First BIAB - Some questions

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stever1000

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I am using BIABacus software to calculate water volumes needed. I started brewing yesterday morning before I had a cup of coffee and I didn't double check the spreadsheet since I set it up last week, and forgot to change my boil time from 90mins to 60mins...

Long story short I added too much water before full volume mashing and my OG was much lower than expected, and I only had time to boil for 60mins. I added 9 gallons of water to the pot before heating the water, with only 10.5 lbs of grain total. So the mash was very dilute

I used EdWorts haus pale ale, with the following grain:
8lbs 2 row
2lbs vienna
0.5lb cara 8

In a perfect world, max points: (8 x 38 points) + ( 2 x 35 points) + (0.5 x 35 points) = 393
(http://howtobrew.com/book/section-2/what-is-malted-grain/table-of-typical-malt-yields)
Final volume was much higher than expected due to the large amount of water and shorter boiling time (60mins vs 90mins calcuated)
= 6.5gallon (6 gallons into fermenter and 0.5gal didn't fit)
1.060 expected perfect gravity (393/6.5)

Using the refractometer, the actual gravity was 1.040 so the efficiency was 67%

Pre-boil the actual gravity was 1.035. Pre-fermenter it was 1.040

I mashed for 90mins because I didn't have a way to adjust (my feeler gauges only go up to 0.025") the gap on my barley crusher from the factory gap of 0.039". I mashed around 152-154 with a bit of heat loss from the kettle (I dont have foil insulation yet so just used towels)

In the future could I theoretically take a reading at 60mins and if I have time, boil longer to reach my perferred OG? i.e. 1.050
 
In the future could I theoretically take a reading at 60mins and if I have time, boil longer to reach my perferred OG? i.e. 1.050

Yes. Depending on your efficiency you might end up with a different volume than you were expecting, though. This might mess with hop utilization as well. Also, if you're boiling for a very long time for a high-gravity beer, you might develop some kettle caramelization.

If you have an accurate means to determine your pre-boil volume and you know what your boil-off rate is, this might help, and you can adjust your hop schedule accordingly.
 
Yes. Depending on your efficiency you might end up with a different volume than you were expecting, though. This might mess with hop utilization as well. Also, if you're boiling for a very long time for a high-gravity beer, you might develop some kettle caramelization.

If you have an accurate means to determine your pre-boil volume and you know what your boil-off rate is, this might help, and you can adjust your hop schedule accordingly.



Thanks, I will avoid the long boiling time then, I will check out brewers friend
 
@enkamania is absolutely correct about using extract to bump up the gravity of your wort. I do partial-extract batches where I try to get as much fermentable sugar from malt as possible, but to make up for my mash tun's low capacity I usually use some DME. It works great, but I usually end up with partial bags of extract sitting in my freezer for a few months. I don't mind having a little bit of old extract on hand, I usually just use it to make starters or bread/pizza dough.
 
Although your feeler gauges only go up to .025" you can measure much thicker that that by stacking them. A .025 plus a .010 gets you to .035. Accuracy for machining would be compromised by stacking but for setting the gap on your crusher it would be "close enough".
 
Although your feeler gauges only go up to .025" you can measure much thicker that that by stacking them. A .025 plus a .010 gets you to .035. Accuracy for machining would be compromised by stacking but for setting the gap on your crusher it would be "close enough".

Wow...mind blown. It's funny how a simple solution can be right in front of you...
Thanks, I will check and adjust the gap tonight. I was thinking .030"
 
As for the feeler gauges, crush til your scared. You can't crush too fine with BIAB, really.

If your worried about efficiency, 90 min boils are a great way to improve it, especially with BIAB. Just start adding your hops at 60 min, instead of at the beginning, or adjust your recipe accordingly.

A longer mash may not help your effeminacy much, but it might improve your conversion.

A mash out has always seemed to help my extraction efficiency with BIAB, but I'm not sure there's any literature to support that.

Another simple option, is to reserve a gallon of the heated strike water for slowly pouring over the bag while it is draining. It can help with efficiency quite a bit.

65-70% is pretty typical for BIAB.

Good luck!
 
A longer mash may not help your effeminacy much, but it might improve your conversion.

I agree. Longer mashes can do a lot of things, but helping effeminacy probably isn't one. :)

ef·fem·i·nate
əˈfemənət/
adjective
(of a man) having or showing characteristics regarded as typical of a woman; unmanly.

Kidding aside, if your conversion is improved, your efficiency will correspondingly improve. So I don't think the statement above (disregarding typos) is correct.
 
As for the feeler gauges, crush til your scared. You can't crush too fine with BIAB, really.

If your worried about efficiency, 90 min boils are a great way to improve it, especially with BIAB. Just start adding your hops at 60 min, instead of at the beginning, or adjust your recipe accordingly.

A longer mash may not help your effeminacy much, but it might improve your conversion.

A mash out has always seemed to help my extraction efficiency with BIAB, but I'm not sure there's any literature to support that.

Another simple option, is to reserve a gallon of the heated strike water for slowly pouring over the bag while it is draining. It can help with efficiency quite a bit.

65-70% is pretty typical for BIAB.

Good luck!

Thanks, thats great info :mug:

I don't want to crush too fine because that risks clogging of my bag by the fine particles, or causing re circulation problems.

I thought mashing and efficiency were related...Isn't conversion linked to efficiency? The less conversion there is, the lower the extraction efficiency?

I will try a mashout as well as reserving water to pour over the draining bag. I've heard of 80% efficiency for BIAB so that's my target :D
 
Thanks, thats great info :mug:

I don't want to crush too fine because that risks clogging of my bag by the fine particles, or causing re circulation problems.

I thought mashing and efficiency were related...Isn't conversion linked to efficiency? The less conversion there is, the lower the extraction efficiency?

I will try a mashout as well as reserving water to pour over the draining bag. I've heard of 80% efficiency for BIAB so that's my target :D

If the starches are well gelatinized, they can be extracted whether they are converted or not.

Yeah I mean don't grind it to flour, but you'd be surprised how low you can go. I'm using one of the nice bags sold by one of our members here, they rock, super fine mesh fabric. I haven't tried recirculating yet, but was actually planning to on one of my next few brews so we'll see how that goes.

Cheers!
 
You can also add extract to up the gravity. Beersmith has a tool to do that. I found a page where it shows the calculation (looks like you like to do math) http://www.brewgeeks.com/calculate-stuff.html

Excellent advice...plus 1 on this!! I keep some DME handy for OG adjustments or building starters for yeast. I swore when I went AG I'd never buy extract again. Who was I fooling?

Being that you have excess volume and can adjust with DME, hopefully you have a system that can handle odd amounts. Since I keg, I have to stick to 5G or 10G...etc so it fits in a keg. I suppose I could bottle a few if I had excess, but man oh man bottling is the pits to me!
 
Also, dont get too wrapped up in efficiency for efficiency's sake. What you should be striving for is reproducibility or consistency (which means you have predictability). for a 5 gallon batch, the difference in efficiency between 70% and 80% is probably less than a dollar of grain cost.
 
If the starches are well gelatinized, they can be extracted whether they are converted or not.

Yeah I mean don't grind it to flour, but you'd be surprised how low you can go. I'm using one of the nice bags sold by one of our members here, they rock, super fine mesh fabric. I haven't tried recirculating yet, but was actually planning to on one of my next few brews so we'll see how that goes.

Cheers!

Hmm I have to do more reading :confused:

What gap do you use?
 
Tried another test batch... this time my readings were:

1.032 pre boil
1.038 post boil

Why is my preboil gravity so low?
I posted pictures of my crush and mill type and some people said it looked fine.
I maintain a mash temperature of 152F as the recipe stated
I mashed for 60mins, boiled for 60mins
I used 10lbs of grain (all 2row) and started with 8.5gallons of water before mashing

Thoughts?
 
Just an FYI, but a narrow crush in a recirculating BIAB system can actually make your efficiency drop. This is counter to the advice given for traditional BIAB, but has been documented by several folks here in the forum.

I had my first experience with it on my last brew when I tightened my mill to 0.032 from 0.035. Efficiency dropped 5 points from what it should have been, even though I had no recirculation issues.

Next brew day I'm loosening up to 0.040. I expect an increase in efficiency.

Edit: have you mentioned your wort return method? Depending on this answer, you could be experiencing channeling in the grain bed, which would also cause poor efficiency.
 
Tried another test batch... this time my readings were:

1.032 pre boil
1.038 post boil

Why is my preboil gravity so low?
I posted pictures of my crush and mill type and some people said it looked fine.
I maintain a mash temperature of 152F as the recipe stated
I mashed for 60mins, boiled for 60mins
I used 10lbs of grain (all 2row) and started with 8.5gallons of water before mashing

Thoughts?

How big of a batch were you planning when you started with 8.5 gallons? If I were doing a 5 gallon batch I would be starting with much less water, more like 6.5 gallons. If I didn't have enough wort for my pre-boil, I would sparge to volume. That would leave me with a less diluted wort so I would get a higher pre-boil gravity.

TexasWine mentioned recirculating but I don't see you mentioning it. If you aren't recirculating, crush finer, much, much finer. See just how tight you can set the mill and still get grains to go through.
 
Just an FYI, but a narrow crush in a recirculating BIAB system can actually make your efficiency drop. This is counter to the advice given for traditional BIAB, but has been documented by several folks here in the forum.

I had my first experience with it on my last brew when I tightened my mill to 0.032 from 0.035. Efficiency dropped 5 points from what it should have been, even though I had no recirculation issues.

Next brew day I'm loosening up to 0.040. I expect an increase in efficiency.

Edit: have you mentioned your wort return method? Depending on this answer, you could be experiencing channeling in the grain bed, which would also cause poor efficiency.

My crush is set to 0.039" so I thought it would be fine for recirculating?
Right now I am recirculating through the lid and it's dropping onto the surface of the water. I think there's enough water in that the direction of flow is redirected before it hits the water. I have locline I need to attach ASAP
 
How big of a batch were you planning when you started with 8.5 gallons? If I were doing a 5 gallon batch I would be starting with much less water, more like 6.5 gallons. If I didn't have enough wort for my pre-boil, I would sparge to volume. That would leave me with a less diluted wort so I would get a higher pre-boil gravity.

TexasWine mentioned recirculating but I don't see you mentioning it. If you aren't recirculating, crush finer, much, much finer. See just how tight you can set the mill and still get grains to go through.

I'm using BIABacus calculator and if my final volume into the keg is 5 gallons, then it told me to start with 8.5gallons to make up for losses from boil evaporation, wort left in kettle, wort left in fermentor, grain and hop absortion.

Is there a better way to calculate this? I agree, it's definitely very dilute, but I don't know what would be the best starting point until I can verify each loss.

:confused:
 
FWIW, sample size 1.

I had too many grains for the mash tun, so I essentially double mashed with two batches of water and added the final grains on the second mash. My 10 gal AG fly sparge set up get 72-73% efficiency. I hit 69% in this BIAB batch.

If I had just gone with the first runoffs, I wouldn't have hit anywhere near that. I only added base malt to the second batch. I could tell from the color of the second runnings that there was still a lot of stuff left in that grain bed from the first mash.
 
I'm using BIABacus calculator and if my final volume into the keg is 5 gallons, then it told me to start with 8.5gallons to make up for losses from boil evaporation, wort left in kettle, wort left in fermentor, grain and hop absortion.

Is there a better way to calculate this? I agree, it's definitely very dilute, but I don't know what would be the best starting point until I can verify each loss.

:confused:

Lets calculate this backwards. You want 5 gallons into the bottles. Add the trub you will leave in the fermenter (about a quart for me, maybe a little more). There is no reason to leave wort in the kettle, it all settles out in the fermenter and the yeast like the trub and can give you clearer beer with the trub in the fermenter (per an experiment by Brulosophy). Now add in how much you boil off. Most of us boil off between .5 and 1 gallon, you might be more if you don't get the burner turned down enough or boil longer. With that the math works out to about this.
5+.25+1=6.25 plus the amount the contraction of the wort as it cools so lets figure about 6.5 gallons. You'll also lose some to grain absorption so lets guess this at .5 gallons. Now we're up to 7 gallons. That will be close.
 
Lets calculate this backwards. You want 5 gallons into the bottles. Add the trub you will leave in the fermenter (about a quart for me, maybe a little more). There is no reason to leave wort in the kettle, it all settles out in the fermenter and the yeast like the trub and can give you clearer beer with the trub in the fermenter (per an experiment by Brulosophy). Now add in how much you boil off. Most of us boil off between .5 and 1 gallon, you might be more if you don't get the burner turned down enough or boil longer. With that the math works out to about this.
5+.25+1=6.25 plus the amount the contraction of the wort as it cools so lets figure about 6.5 gallons. You'll also lose some to grain absorption so lets guess this at .5 gallons. Now we're up to 7 gallons. That will be close.

Thanks, that was very helpful because I like doing the math myself.

I checked BIABacus against http://simplebiabcalculator.com/ and it gets similar amount (>8gallons).

I think I need to find the exact boil off rate, and the exact amount of trub to make it more accurate. I think previously on a different system I usually got a bit more than 1 quart of trub. But I'm not sure of my boil off rate.

I have the PID set to 212F and it was maintaining 211.5 the entire boil...I'm still learning what the proper boil looks like.

My kettle diameter is 15.75"
 
I plugged my numbers in from a recent brew and think you have to watch out for different assumptions around wort absorption. Both calculators will have a different default grain absorption factor, and the screwybrewer calculator adds on a hop absorption factor on top of kettle loss. Also, some measurements are not adjusted for wort expansion, such as the pre-boil amount. That is why its best to stick with one calculator and dial it in with your equipment/process. For me, I find beersmith to be pretty simple and spot on, but you might have a different preference.
 
I plugged my numbers in from a recent brew and think you have to watch out for different assumptions around wort absorption. Both calculators will have a different default grain absorption factor, and the screwybrewer calculator adds on a hop absorption factor on top of kettle loss. Also, some measurements are not adjusted for wort expansion, such as the pre-boil amount. That is why its best to stick with one calculator and dial it in with your equipment/process. For me, I find beersmith to be pretty simple and spot on, but you might have a different preference.

I'm happy using BIABacus because its free...I just need to dial it in like you said I guess
 
Thanks, I tried that one and got
Total water needed
7.88 gallons with a boil off of 1.5gal/hour

I will experiment more :mug:

Sorry I haven't measured my crush, I have a cheap corona mill powered by black and decker that I've used for years. I can generally get a good idea of a crush just by looking, although it did take some practice (and a couple stuck mashes) to be able to do it. Do you have a link to the photos?

Yeah, no matter what calculator you use, you have to experiment. Eventually you'll get your system dialed in on the water volumes. How much you want to leave for trub is entirely up to you.

I'm sure you already know all this, but I'll say it anyway. The biggest hurdle when it comes to BIAB efficiency is the physical limitations. When you place the grain into the strike water, obviously the starches/sugars start to dissolve into the water. Assuming the grain is crushed well, and the temperature is even remotely close, at some point equilibrium will be reached. If after the mash, the gravity of the wort is 1.038, then the wort "trapped" inside the grain after you remove the bag, must also be 1.038. Let's say there is 3/4 of a gallon of wort in there, that's around 1lb of grain at 75% extraction (very roughly). The problem gets worse with larger batches, and higher gravity beers. Imagine a 1.090 beer! A fly sparger will typically be left with a spent grain gravity of something like 1.010, or even less. The reason why I mentioned longer boils, is because you would be diluting the starches/sugars in the wort and grain, thus extracting more, and re-concentrating them in the boil. Boiling with a little more vigor could help increase your evaporation rate, enabling you to use more water and increase your efficiency. Since you have an electric setup it's not a cost issue, but it would take extra time.

Homebrewers can claim to get any efficiency with any system, but that doesn't make it true, and who knows maybe there are some getting 80% with BIAB and no sparging, but I have my doubts. I don't think it's that homebrewers lie, but that many fail to calculate water volumes correctly. Then they think they are getting this great efficiency, and I'm not one to argue. I think your calculating your volumes pretty accurately because your numbers look pretty typical of what I've seen in my own setup.

I hope you don't think I'm knocking BIAB. I have, and will often still, use that technique. It's fast, simple, requires less equipment and makes good beer.
 
I also boil with the lid mostly closed, I wonder how much this is effecting my evaporation rate?
 
Sorry I haven't measured my crush, I have a cheap corona mill powered by black and decker that I've used for years. I can generally get a good idea of a crush just by looking, although it did take some practice (and a couple stuck mashes) to be able to do it. Do you have a link to the photos?

Yeah, no matter what calculator you use, you have to experiment. Eventually you'll get your system dialed in on the water volumes. How much you want to leave for trub is entirely up to you.

I'm sure you already know all this, but I'll say it anyway. The biggest hurdle when it comes to BIAB efficiency is the physical limitations. When you place the grain into the strike water, obviously the starches/sugars start to dissolve into the water. Assuming the grain is crushed well, and the temperature is even remotely close, at some point equilibrium will be reached. If after the mash, the gravity of the wort is 1.038, then the wort "trapped" inside the grain after you remove the bag, must also be 1.038. Let's say there is 3/4 of a gallon of wort in there, that's around 1lb of grain at 75% extraction (very roughly). The problem gets worse with larger batches, and higher gravity beers. Imagine a 1.090 beer! A fly sparger will typically be left with a spent grain gravity of something like 1.010, or even less. The reason why I mentioned longer boils, is because you would be diluting the starches/sugars in the wort and grain, thus extracting more, and re-concentrating them in the boil. Boiling with a little more vigor could help increase your evaporation rate, enabling you to use more water and increase your efficiency. Since you have an electric setup it's not a cost issue, but it would take extra time.

Homebrewers can claim to get any efficiency with any system, but that doesn't make it true, and who knows maybe there are some getting 80% with BIAB and no sparging, but I have my doubts. I don't think it's that homebrewers lie, but that many fail to calculate water volumes correctly. Then they think they are getting this great efficiency, and I'm not one to argue. I think your calculating your volumes pretty accurately because your numbers look pretty typical of what I've seen in my own setup.

I hope you don't think I'm knocking BIAB. I have, and will often still, use that technique. It's fast, simple, requires less equipment and makes good beer.

Thanks, that was very informative. I will definitely play around with my system more to learn the specifics. I have considered sparging as it sounds like it is benefical :mug:
 
I also boil with the lid mostly closed, I wonder how much this is effecting my evaporation rate?

It shouldn't matter if there is a lid on or not for boil off rate. You add a certain amount of energy (the burner), lose some to the cooling due to convection and radiation from the pot, and the rest of the energy is used to convert the water to steam which escapes. Since at a constant temperature (boiling point of water) the losses to convection and radiation must also be constant (ignoring wind blowing for simplicity) the variable is the amount of energy you put into the boil pot as to how much boil off you have.
 
There are two processes that affect your wort making efficiency, which is known as "Mash Efficiency" (BeerSmith), "Pre-Boil Efficiency" (BrewersFriend), and sometimes "Extract" or "Extraction" Efficiency (most often by pro-brewers.) The first process is saccharification, i.e. converting starch to sugar. This is characterized by "Conversion Efficiency." Conversion Efficiency is defined as the amount of sugar actually created in the mash divided by the maximum amount of potential sugar in the grain bill (and multiplied by 100% to give a percentage efficiency rather than a fractional efficiency.) The second process is separating the sugar from the grain, along with the water that makes up the wort. This process is called "Lautering", and is characterized by "Lauter Efficiency." Lauter Efficiency is defined as the amount of sugar that makes it into the boil kettle divided by the amount of sugar actually created during the mash. And finally, Mash Efficiency is equal to Conversion Efficiency times Lauter Efficiency.

Crush, mash time and to a lesser extent mash thickness and mash pH affect conversion efficiency. Finer crush, longer mash times, and reduced mash thickness can all have a positive affect on conversion efficiency. Lauter efficiency depends on whether or not you sparge, the grain absorption rate, and the the grain bill weight vs. the pre-boil volume. Sparging increases lauter efficiency by reducing the SG of the wort retained by the grain, thus reducing the amount of sugar retained. Reducing the grain absorption rate (by squeezing) reduces the amount of wort and sugar retained, thus improving lauter efficiency. A larger grain weight to pre-boil volume ratio decreases lauter efficiency because a larger percentage of the wort (sugar) gets retained by the grain.

...

If your worried about efficiency, 90 min boils are a great way to improve it, especially with BIAB. Just start adding your hops at 60 min, instead of at the beginning, or adjust your recipe accordingly.
This is primarily due to increased lauter efficiency from a reduced grain weight to pre-boil volume ratio, as explained above, and you mention in a later post.

A longer mash may not help your effeminacy much, but it might improve your conversion.

A mash out has always seemed to help my extraction efficiency with BIAB, but I'm not sure there's any literature to support that.
If saccharification is incomplete (i.e. conversion is less than 100%), then a longer mash can definitely improve conversion efficiency by allowing more conversion to occur during the extended time. Once conversion has reached 100%, more time will not improve conversion efficiency, although it may allow more of the unfermentable sugars to be converted to smaller, fermentable ones.

Likewise a mash out will not improve conversion efficiency if conversion is already complete. If conversion is incomplete, the the mash out is really just providing extended mash time to allow more conversion, and at a faster conversion rate due to the higher temperature (until the enzymes are denatured.) If you are getting higher efficiency with a mash out, that is an indication that your mash is incomplete in the time you allowed.

Another simple option, is to reserve a gallon of the heated strike water for slowly pouring over the bag while it is draining. It can help with efficiency quite a bit.

...

Sparging can have a very large affect on lauter efficiency. If doing a pour over sparge, you should let the bag drain well prior to starting the sparge. The less wort in the grain when the sparge starts, the more effective the sparge will be.

Another option is a dunk (batch) sparge conducted by placing the grain bag in another pot/bucket, adding fresh water to the grain, stirring well, and then pulling and draining the bag again. Again, minimizing the amount of wort in the grain prior to the sparge will increase the efficiency of the sparge.

If the starches are well gelatinized, they can be extracted whether they are converted or not.

Yeah I mean don't grind it to flour, but you'd be surprised how low you can go. I'm using one of the nice bags sold by one of our members here, they rock, super fine mesh fabric. I haven't tried recirculating yet, but was actually planning to on one of my next few brews so we'll see how that goes.

Cheers!
Starches can be gelatinized but still not soluble, and insoluble starches cannot be extracted (although some portion of any colloidally suspended starch my get lautered.) Starches have to be dissolved in the wort to be extracted. What's soluble is the shorter chain starches and sugars.

...

I'm sure you already know all this, but I'll say it anyway. The biggest hurdle when it comes to BIAB efficiency is the physical limitations. When you place the grain into the strike water, obviously the starches/sugars start to dissolve into the water.
The saccharification process is more complicated than this. The original starch is for the most part insoluble, and there is essentially no sugar in the malt initially. Before you can convert starch to sugar, you need to surround the starch molecules with water, and this is called gelatinization. Gelatinization is the slowest step of the saccharification process, so it is the rate limiting step. Once the starch is gelatinized the amylase enzymes can start catalyzing the reaction of starch with water, which chops the starch chains into smaller starch chains and sugars. The smaller starch chains become soluble, and get dissolved into the wort where enzyme reactions can occur even faster. Dissolved starch molecules don't survive long in the wort if there are enzymes present. Incomplete conversion is primarily due to incomplete gelatinization of the grits. Since gelatinization starts at the surface of the grits and proceeds towards the center, the larger the grit, the longer it takes for the grit to completely gelatinize. This is the reason for the crush size effect on conversion efficiency.

Assuming the grain is crushed well, and the temperature is even remotely close, at some point equilibrium will be reached. If after the mash, the gravity of the wort is 1.038, then the wort "trapped" inside the grain after you remove the bag, must also be 1.038. Let's say there is 3/4 of a gallon of wort in there, that's around 1lb of grain at 75% extraction (very roughly). The problem gets worse with larger batches, and higher gravity beers. Imagine a 1.090 beer! A fly sparger will typically be left with a spent grain gravity of something like 1.010, or even less. The reason why I mentioned longer boils, is because you would be diluting the starches/sugars in the wort and grain, thus extracting more, and re-concentrating them in the boil. Boiling with a little more vigor could help increase your evaporation rate, enabling you to use more water and increase your efficiency. Since you have an electric setup it's not a cost issue, but it would take extra time.
Pretty good description. However, the higher SG of the wort doesn't really affect the lauter efficiency. The lower lauter efficiency is due to having proportionately more grain absorbing wort, thus a larger percentage of the total wort volume is held by the grain. If you collect 4 gal of wort and the grain retains 1 gal, your lauter efficiency is 80%, regardless of the wort SG.

Homebrewers can claim to get any efficiency with any system, but that doesn't make it true, and who knows maybe there are some getting 80% with BIAB and no sparging, but I have my doubts. I don't think it's that homebrewers lie, but that many fail to calculate water volumes correctly. Then they think they are getting this great efficiency, and I'm not one to argue. I think your calculating your volumes pretty accurately because your numbers look pretty typical of what I've seen in my own setup.

...
80% mash efficiency is possible with thinner mashes with no-sparge BIAB. But when doing higher gravity beers, the mash thickness tends to go up, so the lauter efficiency goes down. The chart below shows lauter efficiency for no-sparge and equal runnings batch sparge for several different grain absorption rates, over a range of pre-boil volume to grain weight ratios. This shows how large an effect squeezing (grain absorption ratio), and grain bill size have on lauter efficiency.

No Sparge vs Sparge big beers ratio.png

Brew on :mug:
 
Well 3/3 ive managed to f@ck my batch up. This time I didn't turn the element off while monitoring mash temp and raised the mash to 175F...super upset
then my hop sock fell into the kettle and released some hops,which later clogged my pump.
currently, the batch is cooling outside and i probably have to wait till tomorrow or late night to pitch the yeast.
Rant off... hope there's no infection
 
There are two processes that affect your wort making efficiency, which is known as "Mash Efficiency" (BeerSmith), "Pre-Boil Efficiency" (BrewersFriend), and sometimes "Extract" or "Extraction" Efficiency (most often by pro-brewers.) The first process is saccharification, i.e. converting starch to sugar. This is characterized by "Conversion Efficiency." Conversion Efficiency is defined as the amount of sugar actually created in the mash divided by the maximum amount of potential sugar in the grain bill (and multiplied by 100% to give a percentage efficiency rather than a fractional efficiency.) The second process is separating the sugar from the grain, along with the water that makes up the wort. This process is called "Lautering", and is characterized by "Lauter Efficiency." Lauter Efficiency is defined as the amount of sugar that makes it into the boil kettle divided by the amount of sugar actually created during the mash. And finally, Mash Efficiency is equal to Conversion Efficiency times Lauter Efficiency.

Crush, mash time and to a lesser extent mash thickness and mash pH affect conversion efficiency. Finer crush, longer mash times, and reduced mash thickness can all have a positive affect on conversion efficiency. Lauter efficiency depends on whether or not you sparge, the grain absorption rate, and the the grain bill weight vs. the pre-boil volume. Sparging increases lauter efficiency by reducing the SG of the wort retained by the grain, thus reducing the amount of sugar retained. Reducing the grain absorption rate (by squeezing) reduces the amount of wort and sugar retained, thus improving lauter efficiency. A larger grain weight to pre-boil volume ratio decreases lauter efficiency because a larger percentage of the wort (sugar) gets retained by the grain.


This is primarily due to increased lauter efficiency from a reduced grain weight to pre-boil volume ratio, as explained above, and you mention in a later post.


If saccharification is incomplete (i.e. conversion is less than 100%), then a longer mash can definitely improve conversion efficiency by allowing more conversion to occur during the extended time. Once conversion has reached 100%, more time will not improve conversion efficiency, although it may allow more of the unfermentable sugars to be converted to smaller, fermentable ones.

Likewise a mash out will not improve conversion efficiency if conversion is already complete. If conversion is incomplete, the the mash out is really just providing extended mash time to allow more conversion, and at a faster conversion rate due to the higher temperature (until the enzymes are denatured.) If you are getting higher efficiency with a mash out, that is an indication that your mash is incomplete in the time you allowed.



Sparging can have a very large affect on lauter efficiency. If doing a pour over sparge, you should let the bag drain well prior to starting the sparge. The less wort in the grain when the sparge starts, the more effective the sparge will be.

Another option is a dunk (batch) sparge conducted by placing the grain bag in another pot/bucket, adding fresh water to the grain, stirring well, and then pulling and draining the bag again. Again, minimizing the amount of wort in the grain prior to the sparge will increase the efficiency of the sparge.


Starches can be gelatinized but still not soluble, and insoluble starches cannot be extracted (although some portion of any colloidally suspended starch my get lautered.) Starches have to be dissolved in the wort to be extracted. What's soluble is the shorter chain starches and sugars.


The saccharification process is more complicated than this. The original starch is for the most part insoluble, and there is essentially no sugar in the malt initially. Before you can convert starch to sugar, you need to surround the starch molecules with water, and this is called gelatinization. Gelatinization is the slowest step of the saccharification process, so it is the rate limiting step. Once the starch is gelatinized the amylase enzymes can start catalyzing the reaction of starch with water, which chops the starch chains into smaller starch chains and sugars. The smaller starch chains become soluble, and get dissolved into the wort where enzyme reactions can occur even faster. Dissolved starch molecules don't survive long in the wort if there are enzymes present. Incomplete conversion is primarily due to incomplete gelatinization of the grits. Since gelatinization starts at the surface of the grits and proceeds towards the center, the larger the grit, the longer it takes for the grit to completely gelatinize. This is the reason for the crush size effect on conversion efficiency.


Pretty good description. However, the higher SG of the wort doesn't really affect the lauter efficiency. The lower lauter efficiency is due to having proportionately more grain absorbing wort, thus a larger percentage of the total wort volume is held by the grain. If you collect 4 gal of wort and the grain retains 1 gal, your lauter efficiency is 80%, regardless of the wort SG.


80% mash efficiency is possible with thinner mashes with no-sparge BIAB. But when doing higher gravity beers, the mash thickness tends to go up, so the lauter efficiency goes down. The chart below shows lauter efficiency for no-sparge and equal runnings batch sparge for several different grain absorption rates, over a range of pre-boil volume to grain weight ratios. This shows how large an effect squeezing (grain absorption ratio), and grain bill size have on lauter efficiency.

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Brew on :mug:

This is the most awesome beer post ever!
 
Thanks, but I wouldn't rate it that high. There's a lot of good stuff out there, and it helped me learn a lot.

Brew on :mug:

Agreed, that was very informative. It sounds like I have a lot more reading to do as well :mug:

Thanks Doug!!
 

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