Boil off different for high gravity?

[jeeppilot]

My last two high gravity beers have been way short on OG. Today’s is especially aggravating. My pre-boil volume and gravity were dead on to the recipe (1.033 or 1.051 with the late sugar accounted for and 4.8 gal). Boiled for 90 minutes shooting for 1.081 and 3 gal post boil. Ended up dead on volume, but 1.063. Double checked recipe, dilution rates. Used two different refractometers and my Tilt. All read the same.

What am I missing? Does the concentration rate change the higher the gravity gets? My calculators don’t say so. But I’m out of ideas.

https://www.brewersfriend.com/homebrew/recipe/print/848854

 

[Spyderbyte07]

My last two high gravity beers have been way short on OG. Today’s is especially aggravating. My pre-boil volume and gravity were dead on to the recipe (1.033 or 1.051 with the late sugar accounted for and 4.8 gal). Boiled for 90 minutes shooting for 1.081 and 3 gal post boil. Ended up dead on volume, but 1.063. Double checked recipe, dilution rates. Used two different refractometers and my Tilt. All read the same.

What am I missing? Does the concentration rate change the higher the gravity gets? My calculators don’t say so. But I’m out of ideas.

https://www.brewersfriend.com/homebrew/recipe/print/848854

I can’t view your recipe without a brewers friend account.

How much sugar did you add? And what does your “1.051 with the late sugar accounted for” calculation look like? Yes, 4.8 gallons of 1.051 wort would boil down to 3 gallons of 1.083, but the late addition sugar isn’t going to get more concentrated throughout the boil.

With that said, even if you were planning the sugar to add 18 points per finished gallon, 4.8 gallons of 1.033 wort boils down to 3 gallons of 1.053 wort. Adding the sugar should bring it to 1.071.

How late was your sugar addition? Is there any chance it didn’t have a chance to fully dissolve? I’d be surprised, but I did have that happen once with a flameout honey addition.

I would also ask the temperature of your preboil wort when you measured the gravity (temperature correction calculators seem to get wildly inaccurate once you get very far from calibration temperature), but a refractomer uses such a small sample it should cool it down very quickly.

 

[jeeppilot]

I can’t view your recipe without a brewers friend account.

How much sugar did you add? And what does your “1.051 with the late sugar accounted for” calculation look like? Yes, 4.8 gallons of 1.051 wort would boil down to 3 gallons of 1.083, but the late addition sugar isn’t going to get more concentrated throughout the boil.

With that said, even if you were planning the sugar to add 18 points per finished gallon, 4.8 gallons of 1.033 wort boils down to 3 gallons of 1.053 wort. Adding the sugar should bring it to 1.071.

How late was your sugar addition? Is there any chance it didn’t have a chance to fully dissolve? I’d be surprised, but I did have that happen once with a flameout honey addition.

I would also ask the temperature of your preboil wort when you measured the gravity (temperature correction calculators seem to get wildly inaccurate once you get very far from calibration temperature), but a refractomer uses such a small sample it should cool it down very quickly.

Sorry, I guess I didn’t know a BF account was needed to view that shared recipe and I’m not sure how to share it any other way. I’ll see if I can change that.

My late sugar addition was done at 10 minutes left in the boil and was 1 lb. Pre-boil gravity was 1.033 and 18 points from the sugar should bring it to 1.051. I was under the impression sugar/candi sugar/honey is usually added near the end of the boil...just enough to sterilize and dissolve it. But by these calcs I should have added it after the mash at the start of the boil??

There is a late addition selection in my recipe which was selected to account for it not being mashed, but I’m not sure exactly when the recipe accounts for it being added.

 

[Big Monk]

Sorry, I guess I didn’t know a BF account was needed to view that shared recipe and I’m not sure how to share it any other way. I’ll see if I can change that.

My late sugar addition was done at 10 minutes left in the boil and was 1 lb. Pre-boil gravity was 1.033 and 18 points from the sugar should bring it to 1.051. I was under the impression sugar/candi sugar/honey is usually added near the end of the boil...just enough to sterilize and dissolve it. But by these calcs I should have added it after the mash at the start of the boil??

There is a late addition selection in my recipe which was selected to account for it not being mashed, but I’m not sure exactly when the recipe accounts for it being added.

After performing some back of the envelope calculations, it appears you may have picked the wrong ppg value for the sugar. What value does BF assume for the sugar you used? You arent going to get 18 points out of 1 lb of sugar at those volumes and gravities.

 

[CascadesBrewer]

Adding 1 lb of Sugar to 4.8 gals of wort would raise the gravity 9.6 points. So your pre-boil gravity would be around 1.043. Boiling this down to 3 gals should yield a gravity of 1.068. Calculating the sugar addition into 3 gals of wort should add 15 gravity points...so your 1.033 wort would boil to 1.053 then the sugar would bring you up to 1.068.

The difference between your actual of 1.063 and the calculated 1.068 is likely just a measurement error (volume or gravity...could just be to the expanded volume that hot water takes up).

 

[Big Monk]

A few things:

1.) The calcs are going to depend highly on the ppg value used for the sugar. Given the known values, 45 ppg (hard sugar) yields 14 gravity points, while 32 ppg (syrup) yields 10 gravity points. I'm accounting for actual volume here by doing the following:

Interim Boil Volume = Preboil Volume - ( Boil Evaporation - ( Boil Evaporation * ( Time of Sugar Addition / Boil Duration ) ) )

Interim Boil Volume = 4.80 - ( 1.80 - ( 1.80 * ( 10 / 90 ) ) ) = 3.20 gal

2.) 1.80 gal of Boil Evaporation on a 4.80 gal preboil volume is insane! That's almost 40% boil off.

 

[jeeppilot]

Adding 1 lb of Sugar to 4.8 gals of wort would raise the gravity 9.6 points. So your pre-boil gravity would be around 1.043. Boiling this down to 3 gals should yield a gravity of 1.068. Calculating the sugar addition into 3 gals of wort should add 15 gravity points...so your 1.033 wort would boil to 1.053 then the sugar would bring you up to 1.068.

The difference between your actual of 1.063 and the calculated 1.068 is likely just a measurement error (volume or gravity...could just be to the expanded volume that hot water takes up).

This is exactly how my actual numbers went! I used the BF default setting for sugar and just figured it was correct. I imagine plain sugar is a widely enough used ingredient someone would have noticed an error if BF had its points/lb listed wrong.

Coincidentally, this happened to me on my last brew also which had a late addition of D-180. Same issue, different ingredient, so I imagine I’m using something incorrectly in the software.

 

[jeeppilot]

 

[jeeppilot]

 

[CascadesBrewer]

Based on the numbers shown (PPG 46 = 18.4 OG) it must assume that you add the 1 lb of sugar into the 2.5 gals of volume in the fermenter. To get to 1.082 the software must be thinking you boil down your 4.8 gals to 2.5 gals and all of that 2.5 gals makes it into the fermenter. I have not used Brewer's Friend, but I would think there is a place where you enter your boil off rate and your kettle loss values. I would check those.

 

[jeeppilot]

Based on the numbers shown (PPG 46 = 18.4 OG) it must assume that you add the 1 lb of sugar into the 2.5 gals of volume in the fermenter. To get to 1.082 the software must be thinking you boil down your 4.8 gals to 2.5 gals and all of that 2.5 gals makes it into the fermenter. I have not used Brewer's Friend, but I would think there is a place where you enter your boil off rate and your kettle loss values. I would check those.

My water requirements go something like:

Pre-boil vol: 4.83
Boil off losses: (1.88)
Vol increase from late additions: 0.07
Hops absorption losses: (0.03)
Kettle dead space: (0.25)
Chiller losses: (0.25)
Amt going into fermenter: 2.5

So these numbers should be right, and I’ve never had any issues hitting my marks on a beer without a late sugar addition. I’m certain the answer lies there somewhere.

On another note a tried entering the same recipe into Beersmith3 and came up with virtually the same numbers. 1.037 pre-boil gravity and 1.081 OG. It even asked me how many minutes left in the boil I’d add the sugar. I used 10 minutes, same as what BF says it uses.

 

[jeeppilot]

A few things:

1.) The calcs are going to depend highly on the ppg value used for the sugar. Given the known values, 45 ppg (hard sugar) yields 14 gravity points, while 32 ppg (syrup) yields 10 gravity points. I'm accounting for actual volume here by doing the following:

Interim Boil Volume = Preboil Volume - ( Boil Evaporation - ( Boil Evaporation * ( Time of Sugar Addition / Boil Duration ) ) )

Interim Boil Volume = 4.80 - ( 1.80 - ( 1.80 * ( 10 / 90 ) ) ) = 3.20 gal

2.) 1.80 gal of Boil Evaporation on a 4.80 gal preboil volume is insane! That's almost 40% boil off.

I have a Megapot 1.2 and it seems like 5 qts/hr is pretty standard for the 1.2 kettle? For a 90 minute boil 1.8 gal is about right and I don’t think I’m boiling it all that “hard”.

 

[Big Monk]

I have a Megapot 1.2 and it seems like 5 qts/hr is pretty standard for the 1.2 kettle? For a 90 minute boil 1.8 gal is about right and I don’t think I’m boiling it all that “hard”.

That just seems like a lot. To be boiling off 40% of the entire volume of the batch? Does it have a lid? Have you tried covered boils before?

I’m also thinking from a volume economics standpoint as well.

 

[jeeppilot]

That just seems like a lot. To be boiling off 40% of the entire volume of the batch? Does it have a lid? Have you tried covered boils before?

I’m also thinking from a volume economics standpoint as well.

I have never done covered boils... I always thought one wasn’t supposed to? [emoji51]

 

[Big Monk]

I have never done covered boils... I always thought one wasn’t supposed to? [emoji51]

Well, let me back up. If you were doing a normal 60 minute boil, then you would be losing about 25% of your volume to evaporation rather than about 38%. Still, 25% of your volume to the air?

I would make sure you aren’t boiling too hard. A simmer is all you need. If you are seeing a rocking, rolling boil, you are likely boiling too hard.

If that isn’t the case, you may try covering the boil for the first 70% of the time then taking it off for the remainder while ensuring you tone down the heat input.

There really is no good reason to boil the bejesus out of the wort or sacrifice 25-40% of it to the atmosphere of you don’t have to.

 

[jeeppilot]

Well I’m certainly closer but can’t say I have figured out the issue yet. It definitely is a late sugar addition issue, not boil-off rate. I have plugged the recipe into Beersmith3 as well as Brewers Friend and both come up with the same numbers. They don’t seem to coincide with manual math, but they match each other. So that seems to eliminate a Brewers Friend software error. Brewers Friend calculates late additions to be made at 10 minutes remaining in the boil, Beersmith you can specify, so I set it to 10 also. 2 out of 2 misses isn’t a good record so any other ideas on where I’m dorking this up? Again this is only occurring when I use late sugar additions, otherwise my numbers are typically dead on.

 

[Spyderbyte07]

My late sugar addition was done at 10 minutes left in the boil and was 1 lb. Pre-boil gravity was 1.033 and 18 points from the sugar should bring it to 1.051. I was under the impression sugar/candi sugar/honey is usually added near the end of the boil...just enough to sterilize and dissolve it. But by these calcs I should have added it after the mash at the start of the boil??

10 minutes left in the boil is plenty of time for the sugar to sanitize and dissolve, no need to add it any earlier.

This is exactly how my actual numbers went! I used the BF default setting for sugar and just figured it was correct. I imagine plain sugar is a widely enough used ingredient someone would have noticed an error if BF had its points/lb listed wrong.

Based on the numbers shown (PPG 46 = 18.4 OG) it must assume that you add the 1 lb of sugar into the 2.5 gals of volume in the fermenter. To get to 1.082 the software must be thinking you boil down your 4.8 gals to 2.5 gals and all of that 2.5 gals makes it into the fermenter. I have not used Brewer's Friend, but I would think there is a place where you enter your boil off rate and your kettle loss values. I would check those.

46 points per pound of table sugar is correct. As CascadeBrewer is saying, you need to look at your volume settings.

Well I’m certainly closer but can’t say I have figured out the issue yet. It definitely is a late sugar addition issue, not boil-off rate. I have plugged the recipe into Beersmith3 as well as Brewers Friend and both come up with the same numbers. They don’t seem to coincide with manual math, but they match each other. So that seems to eliminate a Brewers Friend software error. Brewers Friend calculates late additions to be made at 10 minutes remaining in the boil, Beersmith you can specify, so I set it to 10 also. 2 out of 2 misses isn’t a good record so any other ideas on where I’m dorking this up? Again this is only occurring when I use late sugar additions, otherwise my numbers are typically dead on.

Beersmith has a "Trub Loss" setting. Try setting that to 0.53 gallons to account for your Hops absorption losses: (0.03), Kettle dead space: (0.25), and Chiller losses: (0.25). This way it will account for your late addition sugar being diluted into 3 gallons (well, 3.03), but only 2.5 of those gallons make it into the fermenter.

 

[jeeppilot]

10 minutes left in the boil is plenty of time for the sugar to sanitize and dissolve, no need to add it any earlier.



46 points per pound of table sugar is correct. As CascadeBrewer is saying, you need to look at your volume settings.

Beersmith has a "Trub Loss" setting. Try setting that to 0.53 gallons to account for your Hops absorption losses: (0.03), Kettle dead space: (0.25), and Chiller losses: (0.25). This way it will account for your late addition sugar being diluted into 3 gallons (well, 3.03), but only 2.5 of those gallons make it into the fermenter.

Here is my volume breakdown for the batch in question.

It seems from looking at this that we are on the same page here. 4.83 boiling off 1.88 comes down 3.0. Late sugar increase, hops absorption decrease then 0.25 dead space and 0.25 chiller is 2.5 into the fermenter. Does that look correct?

 

[Big Monk]

Here is my volume breakdown for the batch in question.

View attachment 633718

It seems from looking at this that we are on the same page here. 4.83 boiling off 1.88 comes down 3.0. Late sugar increase, hops absorption decrease then 0.25 dead space and 0.25 chiller is 2.5 into the fermenter. Does that look correct?

Post boil losses won’t affect the gravity though.

 

[jeeppilot]

Post boil losses won’t affect the gravity though.

Exactly, only brewhouse efficiency. So my volumes appear correct here.

 

[Big Monk]

Exactly, only brewhouse efficiency. So my volumes appear correct here.

So it would appear one of two things happened:

1.) Volume measurement error;

Or

2.) Gravity measurement error.

Just to be clear: you used table sugar as outlined in the recipe, correct?

 

[jeeppilot]

So it would appear one of two things happened:

1.) Volume measurement error;

Or

2.) Gravity measurement error.

Just to be clear: you used table sugar as outlined in the recipe, correct?

I ended up using turbinado, which to my knowledge is the same ppg, just different srm. I will say I added it closer to 0 minutes instead of 10. If I’m doing my math correct that would be 15.3 points (46/3) where as at 10 minutes it would be 14.3 points (46/3.2)... a difference of 1 point. Negligible and nowhere near the 15 I ended up short.

I can’t imagine a gravity error since I used two different refractometers (a buddies and mine) and my Tilt. All say the same. I flamed out with a visible 3.1 gallons in the kettle so with shrinkage I should be at 3 gal post boil.

Hard part I’m having in this is 2/2 on late sugar addition brews. Every other brew I’m nailing numbers.

 

[Big Monk]

I ended up using turbinado, which to my knowledge is the same ppg, just different srm. I will say I added it closer to 0 minutes instead of 10. If I’m doing my math correct that would be 15.3 points (46/3) where as at 10 minutes it would be 14.3 points (46/3.2)... a difference of 1 point. Negligible and nowhere near the 15 I ended up short.

I can’t imagine a gravity error since I used two different refractometers (a buddies and mine) and my Tilt. All say the same. I flamed out with a visible 3.1 gallons in the kettle so with shrinkage I should be at 3 gal post boil.

Hard part I’m having in this is 2/2 on late sugar addition brews. Every other brew I’m nailing numbers.

Turbinado is probably closer to 43-44 ppg. Not a humongous difference but when you are troubleshooting, everything counts.

Are you sure you weren’t low on mash extract? Can you show the screens from brewers friend for estimated gravity?

 

[Spyderbyte07]

I will say I added it closer to 0 minutes instead of 10. If I’m doing my math correct that would be 15.3 points (46/3) where as at 10 minutes it would be 14.3 points (46/3.2)... a difference of 1 point. Negligible and nowhere near the 15 I ended up short.

Final gravity wise it doesn’t matter when in the boil you add the sugar. You’re only boiling off water; the full pound of sugar will remain at the end of the boil.

Sure, if you were to measure a preboil gravity before and after adding the pound of sugar to those 4.8 gallons you would only see an increase of 9 points at that time, but once you boiled off your 1.8 gallons of water the sugar would be more concentrated and your final gravity would be 15 points higher than if you hadn’t used sugar.

 

[jeeppilot]

Turbinado is probably closer to 43-44 ppg. Not a humongous difference but when you are troubleshooting, everything counts.

Are you sure you weren’t low on mash extract? Can you show the screens from brewers friend for estimated gravity?

I hope this is the one you’re looking for.

Measured (twice actually) 1.033 pre-boil at 4.9 gal at 148F. Dead on estimated pre-boil gravity and volume.

 

[Big Monk]

I hope this is the one you’re looking for.

View attachment 633758

Measured (twice actually) 1.033 pre-boil at 4.9 gal at 148F. Dead on estimated pre-boil gravity and volume.

Something is not right. Even if you account for large amounts of evaporation, you’d need about 28 gravity points from sugar to hit your estimated OG. That’s not possible based on your numbers.

Can you post the grain amounts you used? I’ll run some analysis tomorrow. My guess is there is something amiss in either your profile on BF or in the BF algorithm.

If you can give me the following (here or in PM), i can run some analysis for you:

1.) Full recipe with grains and sugars;
2.) Equipment profile including displacement rate, absorption rate, mlt deadspaces, etc;
3.) Estimated volumes;
4.) Actual measured brewday values

Some of that is already here so if you can fill in the gaps i can help you work through the troubleshooting.

 

[jeeppilot]

I think I have figured something out here that potentially is an issue. I'm going to try again and link the whole recipe. I have it selected to be a public recipe and I'm using the share as URL, so I hope non-BF folks can see this. If not, I'm piecing together some screen shots in here.

https://www.brewersfriend.com/homebrew/recipe/view/843769/lematre-s-cosmic-tripel

Recipe

Water Volumes

To be very clear here... 90 minute boil, with 0.5 gal combined loss to kettle dead space and chiller, so my post-boil volume is 3.0 gal and is not directly shown on the water volumes. The final 2.5 gal is in my fermenter after kettle dead space, hop absorption and chiller losses.

See the next two pictures, one of the detailed grist bill and a crude spreadsheet I made. I figured each individual ppg for each grain. Pay attention to the yellow boxes on the spreadsheet. These are the points added at 2.5 gal volume and with my brewhouse 75% efficiency applied.

Detailed Grist

Spreadsheet

To the points:

- All grains INCLUDING the late sugar addition were calculated at 2.5 gal, which is my volume in the fermenter! I boiled down to 3 gal, and had .5 gal losses.

- The late sugar addition DID NOT have the 75% efficiency applied.

So my questions/conclusions are:

- Why is the software calculating a boil down to my fermenter volume? Even with my batch size set to 2.5 gal and "Fermenter", wouldn't the OG calculation be based on the points at 3 gal (my flameout volume) with the brewhouse efficiency applied?

- Why is the late sugar addition the only thing NOT having the 75% brewhouse efficiency applied? Is it because it 100% fermentable? But then Carapils, Aromatic, Pilsner and Rye all have differing fermentability, but are being applied the same.

- There is a selection in the advanced recipe stats section that I recently saw and have been researching to understand exactly what it means. It is labeled "Use Boil Size and Boil Evaporation Rate". Selecting this box changes the OG significantly in my recipes. Having now put together this spreadsheet and comparing those numbers, it appears this selection uses my flameout volume to calculate the OG!!! This makes sense to me. Question 1, does not, unless perhaps you have ZERO losses from kettle to fermenter.

- According to my spreadsheet, taking all the 3 gal points applied with 75% except the late sugar which I added at 3.2 gal and DID NOT apply the 75% efficiency, then my OG should have 67.5, rounded up to 68. With the above mentioned Boil Size and Evaporation Rate box selected, BF calculates an OG of 1.070. Pretty darn close and likely acceptable in rounding differences. Most importantly, my measured OG was 1.067!

So, although most of my recipes have somehow been coming out nearly spot on for the last couple years, it seems I need to change my selection to use Boil Size and Boil Evaporation Rate to get the most accurate numbers. At least until I redesign my system/process to improve my post-boil losses. It would seem the closer that gets to zero, the less impact the selection would have.

@RPIScotty - Thanks for all your input and continuing on this thread as I worked this out.

@Spyderbyte07 - You first clued me in to the late sugar points not being correct which eventually got me to my destination.

@CascadesBrewer - You thought that the recipe was calculating the late sugar addition at 2.5 gal volume which includes my post-boil losses...well, you were right and then some!

@Yooper - This (at least partly) addresses our email discussion.

 

[Yooper]

Remember that the reason that sugar doesn't count 75% towards your efficiency is because the sugars are already there and don't get mashed (like if it was extract or honey or something like that).
So you are really in the ballpark with a difference of .002!

 

[Big Monk]

So where did the original 1.081 O.G. come from?

 

[doug293cz]

My last two high gravity beers have been way short on OG. Today’s is especially aggravating. My pre-boil volume and gravity were dead on to the recipe (1.033 or 1.051 with the late sugar accounted for and 4.8 gal). Boiled for 90 minutes shooting for 1.081 and 3 gal post boil. Ended up dead on volume, but 1.063. Double checked recipe, dilution rates. Used two different refractometers and my Tilt. All read the same.

What am I missing? Does the concentration rate change the higher the gravity gets? My calculators don’t say so. But I’m out of ideas.

https://www.brewersfriend.com/homebrew/recipe/print/848854

Here's the proper way to do the math:

4.8 gal of 1.033 wort has 4.8 * 33 = total 158.4 gravity points

Adding 1 lb of table sugar adds a total of 46 points, so your total points value is: 158.4 + 46 = 204.4 pts

3 gal with 204.4 pts equals 204.4 pts / 3 gal = 68.1 pts/gal, which converts to an OG of 1.068.

The difference between 1.063 and 1.068 is likely attributable to volume measurement errors, which become more important with smaller batch sizes.

Brew on