Getting Frustrated with Beersmith

[Gustatorian]

This is infinitely frustrating.

Using the sessions tab after a brew session should really help dial in your system...but it's not.

Currently, I'm working on 2 different equipment settings (no-sparge low-gravity and no-sparge mid-gravity).

Values I know and can adjust:

1. Grain Absorption. I'm constantly readjusting the grain absorption to find a mean for all grain bills (since you can only have 1 for the entire program),

2. Boil Off Rate. I adjust the boil-off rate based on the brew session, and then plug those numbers into the equipment profile.

3. MLT Dead Space: Measured this with the help from this thread. It should stay fixed.

4. Trub Loss: I have the ability to change this, but I feel like I shouldn't. To me, if you start with a specific total volume for a no-sparge brew, then collect a specific volume to boil after the mash, then collect a certain amount in the fermentor, BeerSmith should give you this value. I continue to document the trub loss, but it's difficult to measure as a volume, especially with the expansive capabilities of hops within that volume.

Once I plug every known value into the equipment, it changes the necessities for a specific recipe...upping the total volume of water, misjudging the pre-boil volume, etc. If I were to brew that recipe again, with that specific equipment profile (using those newly recommended volumes) I would again have to readjust because my gravity numbers will be off. This program makes you constantly chase numbers. Plugging a value in will change another and so on...

What am I missing?

 

[Oginme]

(1) Grain absorption should be fairly constant if you are consistent in your process. I've tracked mine over 100+ BIAB brews and find no correlation (r-squared - 0.032) in my system between grain absorption and grain weight into the mash. There is some variability which I can track quite closely to the use of wheat and rye malt and flaked grains.

(2) Boil off rate is somewhat dependent upon the time of year and ambient conditions as well as your ability to reproduce a consistent heat supply. Inside on my stove, I am very consistent whereas outside in the fall and spring, there is a lot more variability due to the temperature and lack of good controls on my propane burner. Inside, my boil off rate has a variability of around 2% and outside it is slightly more than 10%. In my case this is highly process and control issues. I use an average boil off rate based upon 100+ calculations for my indoor BIAB and 6 readings for my outdoor brewing.

(3) You are correct, this should remain a constant.

(4) BeerSmith treats the trub loss as a FIXED variable. YOU set the value and BeerSmith uses this value and the volume to fermenter to back calculate the volumes needed through the process. The software cannot calculate the trub loss for you unless you fix another volume target in the system as there would be too many variables to solve for. I aim for 10 liters in the fermenter and 1 liter of trub in my indoor BIAB system. I typically get 10 to 10.5 liters in the fermenter and 0.5 to 1 liter of trub. There are always some minor variation, but it is less than 100 ml and can be related to my starting volume being +/- 0.1 liter.

My advice is not to plug the numbers from one brew into the next, but use the average of at least 3 to 5 brews as a starting point. No one process is perfectly consistent and some variability should be expected. Once you have your volumes coming out within your margin of being able to measure them, your brew house efficiency (and therefore, mash efficiency) will become more consistent and you will get repeatable gravity readings. Using this approach, the last time I made a change to my equipment profile was 34 brews ago when we bought a new gas stove with a higher BTU burner output.

 

[pricelessbrewing]

Trub loss will vary with recipe, as it's tied to the protein content of the grain, how much grain there is, how big the wort volume was (more wort = longer heating time), and how much hops you used. Beersmith ignores this, and treats it as a constant.

Other than that, the rest are pretty constant, absorption rate varies slightly with types of grain (moisture content of grain, and wheat vs barley etc). Mashtun loss should be a fixed volume.

 

[jmark]

I set the trub loss to a constant for my equipment profile. Even though, in practice, the amount of trub will change from batch to batch, I don't mind leaving some extra wort in the kettle as I'm simply targeting a specific amount of wort into the fermenter (typically 5.5 gallons for 5 gallons finished). Yeah, this might be wasteful, but this does ensure consistent measurement and the 'best' quality wort into the fermenter and into the keg. I also brew indoors so my boil-off rate is fairly consistent too. As others have stated, grain absorption doesn't vary much, so that becomes a constant in my system as well. In the end, if I target specific volumes, then my numbers are always either dead-on or only off by a point or two.

All this being said, I *do* change my expected efficiency when using a lot of wheat or rye (drop it by a few points) or when brewing a BIG beer (drop it by about 10 points), but for most other beers I'm very, very close each brew.

 

[PartagasD4]

From my calculations and working with BeerSmith, the following volumes are thermally expanded: Strike water, sparge water, post mash volume, pre- and post-boil volume. Everything else is at room temperature (volume to fermenter, trub loss). I learned several years ago that in order to balance the volumes in my system, I needed to discount the strike water by the thermal expansion coefficient. Otherwise, I would consistently be right around 4% high (on the average) in my final volume of chilled post boil wort [note: I do full volume BIAB, so the water I measure is near room temperature].

MT/LT loss, I cannot comment on, since everything I have is in one kettle.

There is no way to consistently apply a specific temperature to each measurement in the program. I use a thermal expansion or 2%, which is close to where it would be in the mid-150's F. I undershoot my initial water measurement by that 2% and almost always come out within a few 100 ml of my target post boil volume. It is inconvenient at times, but not that hard to compensate for.

Wow, strike and sparge water :smack: now that I look at the brew sheet it plainly tells me to add xx amount of water at xx temperature . For 5 years now I've been adding ~2% too much strike and sparge water. Thank you for this info,

 

[Gustatorian]

(1) Grain absorption should be fairly constant if you are consistent in your process. I've tracked mine over 100+ BIAB brews and find no correlation (r-squared - 0.032) in my system between grain absorption and grain weight into the mash. There is some variability which I can track quite closely to the use of wheat and rye malt and flaked grains.

(2) Boil off rate is somewhat dependent upon the time of year and ambient conditions as well as your ability to reproduce a consistent heat supply. Inside on my stove, I am very consistent whereas outside in the fall and spring, there is a lot more variability due to the temperature and lack of good controls on my propane burner. Inside, my boil off rate has a variability of around 2% and outside it is slightly more than 10%. In my case this is highly process and control issues. I use an average boil off rate based upon 100+ calculations for my indoor BIAB and 6 readings for my outdoor brewing.

(3) You are correct, this should remain a constant.

(4) BeerSmith treats the trub loss as a FIXED variable. YOU set the value and BeerSmith uses this value and the volume to fermenter to back calculate the volumes needed through the process. The software cannot calculate the trub loss for you unless you fix another volume target in the system as there would be too many variables to solve for. I aim for 10 liters in the fermenter and 1 liter of trub in my indoor BIAB system. I typically get 10 to 10.5 liters in the fermenter and 0.5 to 1 liter of trub. There are always some minor variation, but it is less than 100 ml and can be related to my starting volume being +/- 0.1 liter.

My advice is not to plug the numbers from one brew into the next, but use the average of at least 3 to 5 brews as a starting point. No one process is perfectly consistent and some variability should be expected. Once you have your volumes coming out within your margin of being able to measure them, your brew house efficiency (and therefore, mash efficiency) will become more consistent and you will get repeatable gravity readings. Using this approach, the last time I made a change to my equipment profile was 34 brews ago when we bought a new gas stove with a higher BTU burner output.

1) My process has shown me that grain absorption, based on your equation, is a bit higher than what Beersmith provides (1.08-1.106, as compared to the provided 0.96). I've always found this odd, because it would seem that liquor absorption in grain
should be universal, if not fairly close to the value provided. Anyways, based on the previous equations you provided, I'm confused as to when/if I should subtract the MLT dead space at all. I'm wondering if BeerSmith even factors that into the grain absorption. For example, after subtracting the collected pre-boil liquor (10 G, corrected with thermal expansion (1.04) first to 9.615) from the total added (12.15), then subtracting the dead space (0.125 G for me), then dividing it by my total grain (17.88 lbs) and adjusting for measurements, I get 1.078 (close to what I've always gotten). It just feels like my calculated value for grain absorption is too far from what is provided. Should the thermal expansion coefficient be closer to 2%, rather than 4%, at approximately 150ºF? This would give me a value of 0.99, much closer to what BeerSmith provides. Furthermore, should this calculated value be placed in "grain absorption or BIAB grain absorption or both" within the no-sparge RIMS system I use?

2) Boil-Off Rate should be fairly consistent for me, as I brew inside with an electric system always with the same power per my PID.

3) 0.125 G, got it!

4) Trub Loss: I like the idea of zero-ing this value. I get that it's treated as a fixed value, but can't it mess up the entire equipment profile? For example, let's say I had an equipment profile with a trub loss value set at zero. If I were to start with 12 Gallons of liquor, collected 6 into the fermentor, and had an actual 0.5 G trub loss, then I placed that 0.5 G value into the equipment profile - it would adjust all the volume values up. This would mean that the next time I brewed the same recipe on the same equipment profile, I would have 1 G of trub loss. Not to mention the effects this would have on your gravity readings...following me? Furthermore, isn't the batch volume treated as a fixed value? So the only volume values that change while adjusting would be pre-boil volume and total?

When I build my recipes, I first add my raw materials (grains, hops, yeast), then look to BeerSmith to give me the total water necessary. Is this the wrong way of going about things?

Also, how does one measure trub loss in a situation with heavy amounts of hops added to the BK/whirlpool (see photo below). This is with 5.25 ounces added total to the BK/Whirlpool. Isn't guessing the actual amount of trub loss from that photo, then back calculating volumes based on that seem risky? Would it make more sense to zero that trub loss down, collect what is necessary to fill the fermentor, and know that the batch size volume on BeerSmith won't reflect the actual volume within the fermentor?

 

[Gustatorian]

I set the trub loss to a constant for my equipment profile. Even though, in practice, the amount of trub will change from batch to batch, I don't mind leaving some extra wort in the kettle as I'm simply targeting a specific amount of wort into the fermenter (typically 5.5 gallons for 5 gallons finished). Yeah, this might be wasteful, but this does ensure consistent measurement and the 'best' quality wort into the fermenter and into the keg. I also brew indoors so my boil-off rate is fairly consistent too. As others have stated, grain absorption doesn't vary much, so that becomes a constant in my system as well. In the end, if I target specific volumes, then my numbers are always either dead-on or only off by a point or two.

All this being said, I *do* change my expected efficiency when using a lot of wheat or rye (drop it by a few points) or when brewing a BIG beer (drop it by about 10 points), but for most other beers I'm very, very close each brew.

A few questions for you:

You're changing the BH efficiency when brewing with adjuncts/big beers, as that's the only one you can change, correct?

Does this include all adjuncts or just wheat/rye?

What is considered a lot of wheat/rye and why wouldn't Beersmith correct this efficiency for you, this is a yield issue, correct?

 

[Oginme]

You can and should change the grain absorption to match your calculated results. I measure my grain absorption on a hot water to hot wort basis because BeerSmith subtracts this figure before applying the volume correction for thermal expansion on the 'vols' tab. BeerSmith gives you a place in the 'options' to adjust this and other values to match your system.

Regarding your trub, measure that as 3.25 qts of trub and you will be fine. While there are hop solids and protein solids in the solution, the vast majority is water. I've dried down the trub before to get some idea of the volume of solids versus water and it surprisingly very little volume there (in terms of the proteins) and the hop solids have an apparent density of 5 grams/ml when dried. As such an ounce of hops is not an ounce of fluid. One ounce of hops is about 5.7 ml of your trub. So, for example, if you added 5.25 ounces of hops to that recipe, the volume which can be attributed to hop is 5.25 oz / 5.7 g/ml * 28.3 g/ oz = 26 ml. 3.25 quarts is 3075 ml. That is less than 1% of the volume which can be attributed to the hops. It may look like a lot, but much of the volume is water which has been absorbed by the hops.

In terms of the trub loss, you are looking at the calculations backwards. The program starts from the back end: volume to the fermenter and trub loss and work and works the calculations forward to determine the amount of water needed, not by specifying the amount of water and the batch volume and figuring out the volumes in between.

BeerSmith does not change the gravity readings when you change the fermenter volume or trub loss because it does its calculations off of the brew house efficiency. It will adjust the mash efficiency up or down in response to the change in volume. Personally, I don't care for this method of approach, but it is the one that Brad has written into the program to calculate the extracted sugars.

So in your example, if you zeroed out your trub loss and set your fermenter volume for 6 gal, then put 5.5 gal into your fermenter and had 0.5 gal of trub loss, you can set up the program to reflect the 5.5 gal into the fermenter and 0.5 int trub loss and you would not change a thing. If on the other hand, you set the trub loss for 0.5 gal and kept the fermenter volume at 6 gal, then it would respond by increasing the water volume needed to reach this new end point you specified.

 

[Gustatorian]

You can and should change the grain absorption to match your calculated results. I measure my grain absorption on a hot water to hot wort basis because BeerSmith subtracts this figure before applying the volume correction for thermal expansion on the 'vols' tab. BeerSmith gives you a place in the 'options' to adjust this and other values to match your system.

Regarding your trub, measure that as 3.25 qts of trub and you will be fine. While there are hop solids and protein solids in the solution, the vast majority is water. I've dried down the trub before to get some idea of the volume of solids versus water and it surprisingly very little volume there (in terms of the proteins) and the hop solids have an apparent density of 5 grams/ml when dried. As such an ounce of hops is not an ounce of fluid. One ounce of hops is about 5.7 ml of your trub. So, for example, if you added 5.25 ounces of hops to that recipe, the volume which can be attributed to hop is 5.25 oz / 5.7 g/ml * 28.3 g/ oz = 26 ml. 3.25 quarts is 3075 ml. That is less than 1% of the volume which can be attributed to the hops. It may look like a lot, but much of the volume is water which has been absorbed by the hops.

In terms of the trub loss, you are looking at the calculations backwards. The program starts from the back end: volume to the fermenter and trub loss and work and works the calculations forward to determine the amount of water needed, not by specifying the amount of water and the batch volume and figuring out the volumes in between.

BeerSmith does not change the gravity readings when you change the fermenter volume or trub loss because it does its calculations off of the brew house efficiency. It will adjust the mash efficiency up or down in response to the change in volume. Personally, I don't care for this method of approach, but it is the one that Brad has written into the program to calculate the extracted sugars.

So in your example, if you zeroed out your trub loss and set your fermenter volume for 6 gal, then put 5.5 gal into your fermenter and had 0.5 gal of trub loss, you can set up the program to reflect the 5.5 gal into the fermenter and 0.5 int trub loss and you would not change a thing. If on the other hand, you set the trub loss for 0.5 gal and kept the fermenter volume at 6 gal, then it would respond by increasing the water volume needed to reach this new end point you specified.

Not really following your first point. What do you mean by hot water to hot wort basis? I'm also not seeing a "volumes" tab or "options" tab. Did you mean "preferences"? Not seeing "volumes" under there either.

Your trub loss calculations/theory makes sense. Easier to just take the trub value as is, rather than worry about 1%.

Also, should I calculate my grain absorption based on a thermal coefficient lower than 4%, since the beer is roughly 150ºF?

Ok, I'm sorry, I'm trying to figure this out. So if I start with 2 known volumes (my trub loss = 0.8125 G) and Batch Volume (6 G), it will provide me with a pre-boil volume (which BeerSmith gives as 10.16G...in reality it was 10G) and total volume (which BeerSmith gives as 12.7G, and in reality I only added 12.15G) (this is all based on a grain absorption of 1.0800, an average of what I usually see, and based on a 4% thermal coefficient calculation). I see that the gravity readings aren't changing with the alteration of trub loss and batch volume. And although, with my trub loss volume/batch volume/original gravity correct, all other volumes and pre-boil gravity are off. I get that the pre-boil gravity likely won't reflect the true value because it's based on mash efficiency, which BeerSmith is gauging off of BrewHouse efficiency (and if I change that, I'll change my final gravity).

I guess what I'm getting at is that I didn't change my batch volume because I collected exactly 6 Gallons, I increased my trub loss volume because it's what was measured, and, subsequently, it increased the total necessary, which if I replicated this beer again, with that new total, it would completely smudge my numbers. What am I missing?

 

[jmark]

A few questions for you:



You're changing the BH efficiency when brewing with adjuncts/big beers, as that's the only one you can change, correct?



Does this include all adjuncts or just wheat/rye?



What is considered a lot of wheat/rye and why wouldn't Beersmith correct this efficiency for you, this is a yield issue, correct?

Yes, just change the BH efficiency (that has a knock-on effect on mash efficiency). I usually just change it when I've got 20% plus wheat and/or rye and although Beersmith handles the yield properly, I find that I just don't get the same mash efficiency with wheat and rye (technically, I think it's the lauter efficiency that's lower, but BS doesn't seem to capture that). Really, it's just experience I've built up over the years that drives me to lower the BH number when creating a new recipe.

 

[Gustatorian]

Yes, just change the BH efficiency (that has a knock-on effect on mash efficiency). I usually just change it when I've got 20% plus wheat and/or rye and although Beersmith handles the yield properly, I find that I just don't get the same mash efficiency with wheat and rye (technically, I think it's the lauter efficiency that's lower, but BS doesn't seem to capture that). Really, it's just experience I've built up over the years that drives me to lower the BH number when creating a new recipe.

How much are you lowering it? Does this apply to oats/corn/rice too?

 

[jmark]

I drop it 4 points (72% from my typical 76%) for anything with 20% plus wheats, oats, rye... I've never brewed with rice or anything more than a token amount of corn so can't comment there. For high gravity beers - anything above 1.090 - I drop at least 10 points (66% BH). I haven't brewed enough data points that high (maybe 6 or 7 brews over the 8 years I've been brewing) to get a consistent measure but 10 points gets me pretty close.

 

[Oginme]

Not really following your first point. What do you mean by hot water to hot wort basis? I'm also not seeing a "volumes" tab or "options" tab. Did you mean "preferences"? Not seeing "volumes" under there either.

I measure the strike water heated and the collected wort. Since I do BIAB mostly, this difference is my water absorption. For outside brewing, I do the same thing, except that I know my dead space in my mash tun is 0.6 liters. So the grain absorption here is the difference in hot strike water vs collected wort less the 0.6 liters of dead space.

Your trub loss calculations/theory makes sense. Easier to just take the trub value as is, rather than worry about 1%.

Also, should I calculate my grain absorption based on a thermal coefficient lower than 4%, since the beer is roughly 150ºF?

It is up to you. I figure it is the spot where I take most of the important volume readings, so that is where I set mine.

Ok, I'm sorry, I'm trying to figure this out. So if I start with 2 known volumes (my trub loss = 0.8125 G) and Batch Volume (6 G), it will provide me with a pre-boil volume (which BeerSmith gives as 10.16G...in reality it was 10G) and total volume (which BeerSmith gives as 12.7G, and in reality I only added 12.15G) (this is all based on a grain absorption of 1.0800, an average of what I usually see, and based on a 4% thermal coefficient calculation). I see that the gravity readings aren't changing with the alteration of trub loss and batch volume. And although, with my trub loss volume/batch volume/original gravity correct, all other volumes and pre-boil gravity are off. I get that the pre-boil gravity likely won't reflect the true value because it's based on mash efficiency, which BeerSmith is gauging off of BrewHouse efficiency (and if I change that, I'll change my final gravity).

Work the numbers at temperature (with thermal expansion). So your measured volume (if I am reading your numbers correctly) is 12.15 gal of strike water at temperature (?) less 10 gal collected is 2.15 gal. Now subtract your dead space vol of 0.8125 adn teh difference is your grain absorption.

I guess what I'm getting at is that I didn't change my batch volume because I collected exactly 6 Gallons, I increased my trub loss volume because it's what was measured, and, subsequently, it increased the total necessary, which if I replicated this beer again, with that new total, it would completely smudge my numbers. What am I missing?

If you collected 6 gal exactly, and had 0.5 gal of trub,
then your post boil volume was 6.5 gal? Or did you end up with 6 gal but put 5.5 gal into the fermenter? If you ended up with your expected final volume (post boil) then if you add the 0.5 gal of trub, you will need to adjust the fermenter volume down to compensate.

If, however, you are saying that you put 6 gal into the fermenter and ended up with 0.5 gal of trub afterwards, then your post boil volume is actually 6.5 gal and you need to readjust your number for (most likely at this point) boil off to reflect your actual results.

 

[Gustatorian]

If you collected 6 gal exactly, and had 0.5 gal of trub,
then your post boil volume was 6.5 gal? Or did you end up with 6 gal but put 5.5 gal into the fermenter? If you ended up with your expected final volume (post boil) then if you add the 0.5 gal of trub, you will need to adjust the fermenter volume down to compensate.

If, however, you are saying that you put 6 gal into the fermenter and ended up with 0.5 gal of trub afterwards, then your post boil volume is actually 6.5 gal and you need to readjust your number for (most likely at this point) boil off to reflect your actual results.

First off, when does the software know to apply “Grain Absorption” vs. “BIAB Grain Absorption” in an equipment profile?

What “figure" do you mean when you say “BeerSmith subtracts this figure before applying the volume correction for thermal expansion"
When I calculate my grain absorption, I’m measuring a full volume that is cold, then subtracting the MLT dead space, then subtracting the collected wort with a thermal coefficient of 4%. If BeerSmith is already factoring that thermal coefficient in, would I just not divide my collected wort by the thermal coefficient and just subtract it from the total volume (along with the MLT dead space) to get grain absorption? I assume that when Beersmith calculates the total volume and pre-boil volume they do so as cold and hot respectively, am I wrong in this assumption?

Working this out, my total volume COLD was 12.15, collected wort WARM (approx. 150ºF) was 10G and my MLT dead space is 0.125 G. (My trub loss is 0.8125) If I alter the warm collected wort with the thermal coefficient of 4% (dividing by 1.04), my Grain Absorption is 1.078. However, if I alter the cold total volume with the thermal coefficient (12.15 X 1.04) and work through the equation, then my grain absorption is 1.12348. I assume one of those is correct, and what I input into the software would be based on what BeerSmith assumes is warm or cold.

 

[Oginme]

BeerSmith assumes a hot absorption factor. This is illustrated on the 'vols' tab in your recipe, where it calculates the net wort from the water added, it subtracts the volume for grain absorption.

BeerSmith applies the BIAB grain absorption setting when you use a profile which has the box for BIAB with full volume mash clicked (see pic).

 

[Gustatorian]

If you collected 6 gal exactly, and had 0.5 gal of trub,
then your post boil volume was 6.5 gal? Or did you end up with 6 gal but put 5.5 gal into the fermenter? If you ended up with your expected final volume (post boil) then if you add the 0.5 gal of trub, you will need to adjust the fermenter volume down to compensate.

If, however, you are saying that you put 6 gal into the fermenter and ended up with 0.5 gal of trub afterwards, then your post boil volume is actually 6.5 gal and you need to readjust your number for (most likely at this point) boil off to reflect your actual results.

BeerSmith assumes a hot absorption factor. This is illustrated on the 'vols' tab in your recipe, where it calculates the net wort from the water added, it subtracts the volume for grain absorption.

BeerSmith applies the BIAB grain absorption setting when you use a profile which has the box for BIAB with full volume mash clicked (see pic).

Ok, I see that. So currently it states that 12.7 G COLD (which I only added 12.15 G) is needed and it's estimating that 10.16 G (which I only collected 10 G ) of HOT wort. The difference between the two values is the 0.125 MLT dead space and the 2.41 G in the grain (which I measured and input that grain absorption value, 1.08).

What's frustrating is that I know my volume collected, I know my trub loss, I know my MLT dead space, I know my grain absorption, I know my boil off rate...and it's still feeding me a total volume and pre-boil volume that are above what I'm seeing.

Still not seeing the BIAB option on equipment profiles. Is it in the equipment wizard?

 

[Oginme]

The BIAB option is in the mash profile, sorry forgot to specify that.

 

[Gustatorian]

The BIAB option is in the mash profile, sorry forgot to specify that.

When I calculate the volume of wort in grain, I'm adjusting the collected wort so that it is a cold volume, then subtracting it, along with the cold MLT deadspace volume, from the total cold volume added. Does BeerSmith know that this volume is cold though? The "grain absorption" under the Vols tab shows me the value I calculated on paper (2.41 G in the grain), but does it alter that value with the thermal coefficient to give me my wort collected (hot)?

My volumes aren't adding up because of a mistake I'm making here. When I use your equation to calculate grain absorption (12.15G - 10G/1.04 - 0.125 = 2.41 G in grain COLD). 12.15G is what I ACTUALLY added. But, here's the odd thing: BeerSmith is telling me to add 12.44G. 12.44G-2.41G-0.125G = 9.9G. 9.9G is the number BeerSmith is giving me for "Est Pre-Boil Volume". In reality, if I would have added 12.44G, I would have collected much more pre-boil wort (approx 10.2G). This makes me think that my grain absorption is off...

 

[Oginme]

OK, I am going to walk through the process using my average batch numbers. This is in metric, but the basic principles apply.

I have a grain bill of 2.38 kg and a water measured into the kettle (cold) at 16.0 liters. Heated to strike temperature, this is 16.3 liters (hot) of water. When I remove the bag of grain, drain, and squeeze, I get 15.6 liters (hot). My grain absorption is [16.3 liters - 15.6 liters] / 2.38 kg = 0.7 liters / 2.38 kg =0.294 liters/kg. This is equivalent to 0.281 oz/oz as BeerSmith needs this value in English units.

On the 'vols' tab, BeerSmith notes the grain absorption (0.7 liters), the total water added in the mash (16.3 liters) and tells me that I will have 15.6 liters available from the mash (still hot volumes). This is under the 'mash' section of the volume tracking -- all hot (thermally expanded) volume.

It then takes the estimated pre-boil volume of 15.6 liters and subtracts my boil off volume of 4.38 liters for 11.22 liters of wort as the post-boil volume. The program THEN takes out the thermal expansion of 0.22 liters to give me a final volume of 11.0 liters, 10 which go into the kettle and 1 which is trub loss.

 

[Gustatorian]

OK, I am going to walk through the process using my average batch numbers. This is in metric, but the basic principles apply.

I have a grain bill of 2.38 kg and a water measured into the kettle (cold) at 16.0 liters. Heated to strike temperature, this is 16.3 liters (hot) of water. When I remove the bag of grain, drain, and squeeze, I get 15.6 liters (hot). My grain absorption is [16.3 liters - 15.6 liters] / 2.38 kg = 0.7 liters / 2.38 kg =0.294 liters/kg. This is equivalent to 0.281 oz/oz as BeerSmith needs this value in English units.

On the 'vols' tab, BeerSmith notes the grain absorption (0.7 liters), the total water added in the mash (16.3 liters) and tells me that I will have 15.6 liters available from the mash (still hot volumes). This is under the 'mash' section of the volume tracking -- all hot (thermally expanded) volume.

It then takes the estimated pre-boil volume of 15.6 liters and subtracts my boil off volume of 4.38 liters for 11.22 liters of wort as the post-boil volume. The program THEN takes out the thermal expansion of 0.22 liters to give me a final volume of 11.0 liters, 10 which go into the kettle and 1 which is trub loss.

OK this is where I think there is an issue with the original equation you gave me. In the original equation, you change the volume of the collected wort to COLD by dividing the value by 1.04. You then continue with the math. Above, you're altering the total volume and changing it to HOT, then continuing with the math. These will give you two different results.

For example, with the original equation, my fl. oz./oz. grain absorption in 1.078. If I change the total volume to hot, then work through the equation, my fl. oz/oz absorption is 1.123. Math below:

Equation 1: 12.15G - (10G/1.04) - 0.125 = 2.410G. 2.410G in 17.88 lbs of grain comes out to 1.078 fl oz/oz.

Equation 2: (12.15G x 1.04) - 10G - 0.125G = 2.511G. 2.511 G in 17.88 lbs of grain comes out to 1.123 fl oz/oz.

Which one is correct?

A few other questions:

In your case, your "water available from mash" should equal "estimated pre-boil volume", correct? Like you, I don't sparge, but for some reason, when I look under the volume tabs, my "water available from mash" and "sparge volume" = "estimated pre-boil volume". Any clue on how to amend this? I assume there is a way to let BeerSmith know that you're running a No-Sparge system and it will zero that value out for you...or add all of that volume into the "Water available from the mash"...

 

[Oginme]

I have stated several times that the calculations are done on the thermally expanded volume and have been consistent about this fact.

Water available from mash is equivalent to pre-boil volume IF there are no top off water additions made to the kettle. If you are running a no-sparge system, then treat it like a BIAB mash to tell the software that you are using full volume in your mash.

 

[Gustatorian]

I have stated several times that the calculations are done on the thermally expanded volume and have been consistent about this fact.

Water available from mash is equivalent to pre-boil volume IF there are no top off water additions made to the kettle. If you are running a no-sparge system, then treat it like a BIAB mash to tell the software that you are using full volume in your mash.

Oh I totally believe you've been saying that the whole time! So that means, equation 2 is giving me the correct absorption rate, right? Also, does that mean that the "total water needed" that is provided is thermally expanded and I should divide that value by 1.04 to get the amount that I should add to my system?

Don't think I'm not sending you a box of beer once I figure all of this out, either. Not homebrew stuff either lol. You've been a huge help!

 

[Oginme]

Equation (2) is correct, if I am following your numbers correctly: Hot in - hot out.

 

[Gustatorian]

Equation (2) is correct, if I am following your numbers correctly: Hot in - hot out.

Perfect!

So stay with me here...Based on equation 2, my Grain Absorption is 1.1235. I'm plugging this into BIAB grain absorption because, on this system, I don't sparge. It's not giving me a "total water needed" value of 12.64. This has to be a HOT value, correct? That would make sense because 12.64/1.04 = 12.15 (The actual amount of COLD water I added to the system for this brew)

 

[Oginme]

You got it!

 

[Gustatorian]

If you're sparging isn't raising your efficiency, then you're doing it wrong or getting channeling.

Grain absorption is an equipment variable, and you will need to adjust it based on your equipment. 0.08 is typical for a BIABer, if you're using a mashtun with a false bottom or braid, then it's probably 0.12-0.125 gal/lb.

Grain potential (or yield) is given either in PPG, or as a percentage (of the potential of succrose ie 1.046 ppg). You'll need to get that from your recipe, the quickest way is to set beersmith to 100% brewhouse efficiency, and take the predicted OG and do the following. It's a measurement of how much sugar we can expect to extract and be converted during the mash.

OG * wort volume = Total points.

Total points / Total weight of grain = average potential.

Just to verify, the "wort volume" in your equation is "batch size" and "trub loss", correct?

 

[pricelessbrewing]

Just to verify, the "wort volume" in your equation is "batch size" and "trub loss", correct?

When using that trick, use batch size and OG.

You could also use preboil volume and preboil gravity, but you will then need to adjust for the thermal expansion coefficient and you will lose some accuracy due to that adjustment.

The fact that we're on page 15 is a testament on how much beersmith would benefit from some ease of use updates, and how much the community could use a better free alternative...

 

[pricelessbrewing]

I have stated several times that the calculations are done on the thermally expanded volume and have been consistent about this fact.

Water available from mash is equivalent to pre-boil volume IF there are no top off water additions made to the kettle. If you are running a no-sparge system, then treat it like a BIAB mash to tell the software that you are using full volume in your mash.

Just to complicate things further, beersmith does use room temp calculations to determine the total necessary water, and boil off rate I believe is a cold volume as well. The only things adjusted to temperature is wort volume/gravity @ mash, preboil, and postboil, (but lauter tun, and kettle losses are cold volumes, and gravities should NOT be temperature adjusted as they should ALWAYS be done at room temp). Yeah, it's a mess.

I don't recommend using beersmiths temperature adjustments, as it applies to things that it shouldn't apply them to. Instead, set it to zero % and adjust things by hand (or use alternative smarter software for this *cough* *cough*)

(you can double check by setting boil off rate to 0, then changing it to 1 gallon and seeing that the total water needed is 1 gallon more).

 

[Oginme]

Just to complicate things further, beersmith does use room temp calculations to determine the total necessary water, and boil off rate I believe is a cold volume as well. The only things adjusted to temperature is wort volume/gravity @ mash, preboil, and postboil, (but lauter tun, and kettle losses are cold volumes, and gravities should NOT be temperature adjusted as they should ALWAYS be done at room temp). Yeah, it's a mess.

I don't recommend using beersmiths temperature adjustments, as it applies to things that it shouldn't apply them to. Instead, set it to zero % and adjust things by hand (or use alternative smarter software for this *cough* *cough*)

(you can double check by setting boil off rate to 0, then changing it to 1 gallon and seeing that the total water needed is 1 gallon more).

To be honest, the real issue is that BeerSmith is not consistent with how it defines the water volume. While it uses a thermal expansion coefficient, it does not scale the coefficient to the temperature. It also assumes hot wort from the mash but then applies the gravity reading to that hot volume instead of correcting the volume for the thermal expansion.

In the end, these differences usually do not add up to much greater than the error which most people can measure their volumes and if you work the numbers out, you can (and through calculation, usually do) incorporate the differences in volumes between hot and cold into your grain absorption and boil off rates. It is not the cleanest way to balance the system, but it will work to within most people's margin of error.

 

[Gustatorian]

Just to complicate things further, beersmith does use room temp calculations to determine the total necessary water, and boil off rate I believe is a cold volume as well. The only things adjusted to temperature is wort volume/gravity @ mash, preboil, and postboil, (but lauter tun, and kettle losses are cold volumes, and gravities should NOT be temperature adjusted as they should ALWAYS be done at room temp). Yeah, it's a mess.

I don't recommend using beersmiths temperature adjustments, as it applies to things that it shouldn't apply them to. Instead, set it to zero % and adjust things by hand (or use alternative smarter software for this *cough* *cough*)

(you can double check by setting boil off rate to 0, then changing it to 1 gallon and seeing that the total water needed is 1 gallon more).

Ha, This is giving me a headache...it is a practice in education though, I guess…

Just to address both of you guys (Priceless and Oginme)

"While it uses a thermal expansion coefficient, it does not scale the coefficient to the temperature.” So does BeerSmith just scale the adjusted volumes to one temperature across the board? And can this temperature be adjusted?

And for my clarity..

Room Temp Volumes:

“Total Water Needed” i. e. “Total Mash water adds" -If that's the case, then the total water added in my no-sparge system should be this amount, and not this amount divided by the thermal coefficent, correct?

“Boil Off Rate” - Per the equations discussed above, we've always adjusted the values to COLD. Once we've worked through the equation with all values COLD, we plug this number into the equipment profile. Once the number is plugged in, BeerSmith takes this number and feeds us values that are HOT (via altering that value with the thermal coefficient)??? (i.e. Est. Pre-Boil Volume). So, essentially, the Pre-Boil volume value that we measured and used in the equation to get the Boil-Off Rate will not be reflected on the BeerSmith software, but a thermally-expanded value of the Pre-Boil Volume will?



Adjusted to Temp Volumes:

“Est Pre Boil volume” i.e. “Water available from mash”

“Post Boil” - is this “Batch size” and “trub loss”. This is the most troublesome to me. Reason being is that we plug these numbers in. These values are measured at room temp/fermentable temps. Why would they need to be temp-adjust and what temperature would it even be adjusted to?

A few other things...

Priceless, what did you mean by "set it to zero % and adjust things by hand” - ??? Is this adjusting the “cooling shrinkage to 0%” in the equipment profile? If I were to do that, how would I approach calculating my numbers so that BeerSmith provides me with accurate volumes?


Oginme, Based on this... "It also assumes hot wort from the mash but then applies the gravity reading to that hot volume instead of correcting the volume for the thermal expansion.“ - so is the "est pre-boil gravity" reading that BeerSmith feeds us is at hot temps? That doesn't seem right, as a gravity reading at approximately 150ºF would be much lower than the value it is providing.

Also, Priceless, I plan on thoroughly reading/looking through your site today. Hopefully I'll be able to bring more clarity to this situation.

 

[Oginme]

Ha, This is giving me a headache...it is a practice in education though, I guess…

Just to address both of you guys (Priceless and Oginme)

"While it uses a thermal expansion coefficient, it does not scale the coefficient to the temperature.” So does BeerSmith just scale the adjusted volumes to one temperature across the board? And can this temperature be adjusted?

When you enter a thermal expansion of 4% at boil,
it uses this expansion regardless of the temperature the wort is actually at. Thus, it treats the wort collected as if you were measuring the volume at (or near) boiling. The way to accommodate different temperatures is to lower the thermal expansion coefficient to that of the temperature close to where you normally take your volume readings. This is why I set mine for 2% where my wort is when I remove the grain bag (mid 150's).

And for my clarity..

Room Temp Volumes:

“Total Water Needed” i. e. “Total Mash water adds" -If that's the case, then the total water added in my no-sparge system should be this amount, and not this amount divided by the thermal coefficent, correct?

Yes/no/not really. BeerSmith will give you a total water value based upon all water adds (including fermenter top-off), which is one of the places it mixes hot volume with cold volume. Since you do a no-sparge, like I do, this number should be the volume at strike temperature. In reality it is the volume of the water at the thermal expansion you have it set in the program. If you are measuring the water cold (as I do the night before my morning brew), then you should correct this volume back to room temperature.

“Boil Off Rate” - Per the equations discussed above, we've always adjusted the values to COLD. Once we've worked through the equation with all values COLD, we plug this number into the equipment profile. Once the number is plugged in, BeerSmith takes this number and feeds us values that are HOT (via altering that value with the thermal coefficient)??? (i.e. Est. Pre-Boil Volume). So, essentially, the Pre-Boil volume value that we measured and used in the equation to get the Boil-Off Rate will not be reflected on the BeerSmith software, but a thermally-expanded value of the Pre-Boil Volume will?

I've used cold volumes and repeatedly kept running short on my expected finished volume by (wait for it...) my thermal expansion. Since then, I've used the hot rate of evaporation and have been very, very close to my expected finished volumes. Last 40 brews have been net zero post boil volume versus target. Variability is +/- 100 ml on an 11 liter volume (cold).

Adjusted to Temp Volumes:

“Est Pre Boil volume” i.e. “Water available from mash”

“Post Boil” - is this “Batch size” and “trub loss”. This is the most troublesome to me. Reason being is that we plug these numbers in. These values are measured at room temp/fermentable temps. Why would they need to be temp-adjust and what temperature would it even be adjusted to?

BeerSmith is written to accommodate all types of brewing equipment. Therefore, it does some justice and other methods are a bit wanting. If you look at a common system of having an HLT, the water would already be hot, so that is how it is calculated. To accomplish this, Brad has calculated backwards from the finished cold volumes (batch volume, trub loss) and then applied the thermal expansion to the volumes prior to this point. Thus, if you look at his volumes tab, you will see the post boil volume contains the thermal expansion coefficient, and that is subtracted at that point to bring you back to your original targets.

Having the water volume calculated as hot doesn't work quite so well for those of us who do BIAB or start with cold water in a single vessel brewing system. Setting the thermal expansion coefficient back to 0% will normalize for room temperature water, but it will throw off the expected target for wort collected from mash.

A few other things...

Priceless, what did you mean by "set it to zero % and adjust things by hand” - ??? Is this adjusting the “cooling shrinkage to 0%” in the equipment profile? If I were to do that, how would I approach calculating my numbers so that BeerSmith provides me with accurate volumes?


Oginme, Based on this... "It also assumes hot wort from the mash but then applies the gravity reading to that hot volume instead of correcting the volume for the thermal expansion.“ - so is the "est pre-boil gravity" reading that BeerSmith feeds us is at hot temps? That doesn't seem right, as a gravity reading at approximately 150ºF would be much lower than the value it is providing.

NO! Gravity should always be measured at or near the calibration temperature of your hydrometer. The only thing that BeerSmith throws off by using a hot volume and room temperature gravity measurement is the calculation of mash efficiency and the actual gravity target of the wort collected. This number is not huge (basically the value of your thermal expansion coefficient and does not show up until you get to high gravity readings.

Also, Priceless, I plan on thoroughly reading/looking through your site today. Hopefully I'll be able to bring more clarity to this situation.

.

 

[pricelessbrewing]

Only thing I disagree with @Oginme is that boil off is cold. You can check that yourself easily. Set boil off to zero, then set it to 1 gallon. Your total water needed increases by exactly 1 gallon.

If you want variable automated thermal expansion coefficients, you'll need to switch software to mine. As far as I know, mine is the only one doing this right now. Brewtarget may or may not have it, I remember seeing a code commit pushed a long time ago for it, but I don't think it's actually being used in the software right now.

If you want to set the cooling rate to zero %, and adjust by hand you can do so by using my expansion calculator here https://pricelessbrewing.github.io/BiabCalc/#Thermal

 

[Gustatorian]

"Yes/no/not really. BeerSmith will give you a total water value based upon all water adds (including fermenter top-off), which is one of the places it mixes hot volume with cold volume. Since you do a no-sparge, like I do, this number should be the volume at strike temperature. In reality it is the volume of the water at the thermal expansion you have it set in the program. If you are measuring the water cold (as I do the night before my morning brew), then you should correct this volume back to room temperature."


Ah, so if I did change my thermal expansion coefficient to 2%, I would have to divide the volume of water by 1.02 and add that amount of total water, correct?


"I've used cold volumes and repeatedly kept running short on my expected finished volume by (wait for it...) my thermal expansion. Since then, I've used the hot rate of evaporation and have been very, very close to my expected finished volumes. Last 40 brews have been net zero post boil volume versus target. Variability is +/- 100 ml on an 11 liter volume (cold)."

You precision makes me want to readjust my boil-off rate, but Priceless does bring up a good point about the boil-off rate changes.


I’m brewing again tomorrow (low gravity, no-sparge). I’ll put the fine-tuning to the test…will report back.

 

[Gustatorian]

After today’s brew session, it looks like I’ve honed in my No-Sparge system fairly well, at least for low-gravity beers.

I’ll continue to record and chart volumes and gravities, charting grain absorption and boil-off rate for each brew session, to ultimately find a mean value to input into the software (although I may have to make 2 different profiles for Summer/Winter...I do my brewing inside with the door propped open, so there is minimal exposure to the elements).

A few questions:

Are there any other variables I should continue to record and compare between brew session (besides “grain absorption” and “boil-off rate”) I assume the only volume value that should change is the "total water added”. If my boil-off rate is consistent, and I’m recording the same amount of beer into fermentor/trub loss, the only variable that could change my volumes is the grain absorption (that will vary with amount of grain added, obviously, and will be amended in the amount of water added at the beginning).

My biggest issue today was this: Regardless of checking the BIAB option for my No-Sparge system, the software does not change the BH efficiency when decreasing the amount of trub loss. My current Mash Efficiency is in the low 70’s, but my BH efficiency is in the low 60’s. I’d attribute this massive disparity due to how much trub I’m leaving behind. However, if I decide to decrease the trub loss, subsequently decreasing my total water added, it decreases the mash efficiency (narrowing the difference between my BH Efficiency and Mash Efficiency) and maintains the pre-boil gravity? Why would it recognize the input of a decrease in trub loss as something that would effect the mash efficiency? It has nothing to do with the mash! If you decrease your trub loss and subsequently decrease your total water added in a no-sparge/all water added from the beginning, you should see an increase in pre-boil gravity and subsequently original gravity, right? Why would the software not recognize that and amend those values?

Wouldn’t it make more sense to input the decrease in trub loss, the software responds by decreasing the total water added, decreasing the pre-boil volume, increasing the pre-boil gravity and increasing the original gravity. From there, I could decrease the amount of grain I wanted to add if I was shooting for an actual lower target gravity at the newly decreased volume...

 

[pricelessbrewing]

After today’s brew session, it looks like I’ve honed in my No-Sparge system fairly well, at least for low-gravity beers.

Glad to hear it!

A few questions:

Are there any other variables I should continue to record and compare between brew session (besides “grain absorption” and “boil-off rate”)

I would also record conversion, lauter, mash, and brewhouse efficiency. But I'm probably an outlier. I record a lot of things on brewday I would probably get looks if I brought a brewsheet to a club meeting...

I assume the only volume value that should change is the "total water added”. If my boil-off rate is consistent, and I’m recording the same amount of beer into fermentor/trub loss, the only variable that could change my volumes is the grain absorption (that will vary with amount of grain added, obviously, and will be amended in the amount of water added at the beginning).

Correct.

My biggest issue today was this: Regardless of checking the BIAB option for my No-Sparge system, the software does not change the BH efficiency when decreasing the amount of trub loss.

Beersmith NEVER adjusts the BH efficiency. It relies on you telling it what you expect for this brew, on this equipment, for this recipe. If you want something that does, you will need to use my software. AFAIK, noone else does it.

My current Mash Efficiency is in the low 70’s, but my BH efficiency is in the low 60’s. I’d attribute this massive disparity due to how much trub I’m leaving behind. However, if I decide to decrease the trub loss, subsequently decreasing my total water added, it decreases the mash efficiency (narrowing the difference between my BH Efficiency and Mash Efficiency) and maintains the pre-boil gravity? Why would it recognize the input of a decrease in trub loss as something that would effect the mash efficiency? It has nothing to do with the mash! If you decrease your trub loss and subsequently decrease your total water added in a no-sparge/all water added from the beginning, you should see an increase in pre-boil gravity and subsequently original gravity, right? Why would the software not recognize that and amend those values?

Not sure I followed this one, but I'll try. By trub loss, are you referring to kettle losses, or mashtun losses?

Kettle losses basically don't matter as far as beersmith cares, in regards to efficiencies. So when you have a kettle loss of 1 gallon, it increases the water needed by 1 gallon, which dilutes the wort and decreases boil gravity.

Mashtun losses are a factor for lauter efficiency (beersmith doesn't care about this). Mash efficiency = conversion * lauter. Since mashtun losses decreases lauter, they will also decrease mash efficiency. Beersmith does account for it for volumes though, so 1 gallon mashtun loss will decrease your runoff gravity, and boil gravities.

If that's not happening, then I chock it up to Beersmith being dumb again. There may be a "hack" for getting beersmith to "fix" that, but IDK, as I don't really use it much beyond recipe formulation.

Wouldn’t it make more sense to input the decrease in trub loss, the software responds by decreasing the total water added, decreasing the pre-boil volume, increasing the pre-boil gravity and increasing the original gravity. From there, I could decrease the amount of grain I wanted to add if I was shooting for an actual lower target gravity at the newly decreased volume...

Yes, yes it would. That's what my software does. :rockin:

 

[Gustatorian]

"I would also record conversion, lauter, mash, and brewhouse efficiency. But I'm probably an outlier. I record a lot of things on brewday I would probably get looks if I brought a brewsheet to a club meeting…"

How are you measuring conversion, lauter efficiency, and mash efficiency? Obviously BeerSmith will feed you a different mash efficiency than you’re calculating (at least, in my case with the no-sparge set up).

"Beersmith NEVER adjusts the BH efficiency. It relies on you telling it what you expect for this brew, on this equipment, for this recipe. If you want something that does, you will need to use my software. AFAIK, noone else does it.”

Dedicating a good chunk of my day to reading through your site. Get ready for the onslaught of questions

"Not sure I followed this one, but I'll try. By trub loss, are you referring to kettle losses, or mashtun losses?” -

Referring to volume left in the kettle after boil plus loss in tubing/pump during transfer (everything that didn’t make it into the fermentor). My MLT loss is 0.125G consistently, and confirmed with the test you guys walked me through previously.

"Kettle losses basically don't matter as far as beersmith cares, in regards to efficiencies. So when you have a kettle loss of 1 gallon, it increases the water needed by 1 gallon, which dilutes the wort and decreases boil gravity. “

You would think it decreases the boil gravity...but I’m not seeing that reflected within BeerSmith. I see no change reflected in my pre-boil gravity or original gravity when I change my trub loss up or down a gallon. Are you seeing something different? What I DO SEE is a massive fluctuation of Mash Efficiency (while the BH efficiency remains unchanged, obviously).

"Mashtun losses are a factor for lauter efficiency (beersmith doesn't care about this). Mash efficiency = conversion * lauter. Since mashtun losses decreases lauter, they will also decrease mash efficiency. Beersmith does account for it for volumes though, so 1 gallon mashtun loss will decrease your runoff gravity, and boil gravities.”

Not totally following this, do you mind spelling it out for me?

 

[pricelessbrewing]

I'll have to double check the relationship between mash efficiency and kettle losses in beersmith. Sounds like a bug though, as it's mashtun losses that should impact mash Efff, not kettle.

Boil gravity may not be changing since it calculates it backwards based on user input BH eff. It should though (logically speaking), but again I'll have to double check BS formulas.

 

[Gustatorian]

I'll have to double check the relationship between mash efficiency and kettle losses in beersmith. Sounds like a bug though, as it's mashtun losses that should impact mash Efff, not kettle.

Boil gravity may not be changing since it calculates it backwards based on user input BH eff. It should though (logically speaking), but again I'll have to double check BS formulas.

Yea check it out and let me know what you think. Loving the stuff on your site by the way. Working some recipes through the BIAB calc right now. I have a few questions for ya. Will launch them your way once I can organize everything. Cheers!

 

[pricelessbrewing]

Looks like you're correct, since beersmith works from user input on a fixed brewhouse efficiency, changes to mashtun or kettle losses do not change boil gravities correctly.

Mashtun losses don't appear to change any gravity or efficiency estimate.

Increasing kettle losses (trub and chiller), increases preboil gravity (which makes no sense), and increases estimated mash efficiency (which I don't understand why this would occur since kettle losses have no bearing on mash efficiency except for changes in total water needed which beersmith does not use for efficiency calculations, @doug293cz any ideas?)

 

[EarthwormJim]

Looks like you're correct, since beersmith works from user input on a fixed brewhouse efficiency, changes to mashtun or kettle losses do not change boil gravities correctly.

Mashtun losses don't appear to change any gravity or efficiency estimate.

Increasing kettle losses (trub and chiller), increases preboil gravity (which makes no sense), and increases estimated mash efficiency (which I don't understand why this would occur since kettle losses have no bearing on mash efficiency except for changes in total water needed which beersmith does not use for efficiency calculations, @doug293cz any ideas?)

Changes to the kettle losses do effect the pre-boil gravity and mash efficiency correctly, just not intuitively.

Like you said, everything is built on the fixed brew house efficiency. That sets the percentage of the sugar from the grain that gets into the fermentor. All of the other (relavent) values are calulated backwards from there to make/force that to happen. This can end up looking suspicious.

Post-boil and fermentor gravities are equal but the volumes may not be. If there are kettle losses you need a greater quantity of the same gravity wort. This means more total points post-boil which means more total points pre-boil Intuitively, to me at least, it seems the extra volume required pre-boil would cancel out the extra points. It probably does as long as the kettle loss is small enough.

For example, say we are supposed to get 5G of 1.050 wort into the fermentor, no kettle loss and we boil off 1G an hour. That is pre-boil 6G @ 1.04166. If we have a kettle loss of .25G, now we need 5.25G @ 1.050(262.5 points) post boil and get 6.25G @ 1.04200 pre-boil. With .5G kettle loss we get 5.5G @ 1.050(275 points) 6.5G @ 1.04230 pre-boil. I added the extra digits to the gravities just to show the subtle differences with the small volume change. It is climbing slowly, but a large enough loss will have a noticable effect.

This is going to flow further upstream. The extra sugar pre-boil is going to come from the mash. If you get more sugar from the mash your mash must have been more efficient.