Help! Beersmith3 attenuation way off

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CJnCincy

CJnCincy

The Lusk Farm & Brewhouse
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Is there a way to manipulate the attenuation in BS3? The estimated attenuation is typically 10% pts or higher than what I see the yeast capable of. For example:

I'm using WLP003 for an Altbier.
White Labs lists attenuation for this yeast as 73-80%
When looking at this yeast's profile in BS3 it is the same as above.
However in the "session tab" in BS3 it as 87.3% as the estimated attenuation.

If BS3 is using an 87.3% attenuation estimate in recipe formulation, this will throw off my ABV/FG# estimate at a minimum and now I'm left guessing (or doing the math myself) on what OG to hit to meet a specific desired ABV.

This is not an anomaly for me in BS3. Most estimated attenuation % in the "session" way overestimate what the yeast seems capable of, and my own FG numbers are always higher than what BS3 estimates due to this discrepancy.

Is there a way I can edit estimated efficiency in the program?
 
There are a number of factors which are involved in the modeling of the FG calculation. The biggest impact is the yeast attenuation which is based off of the manufacturer's published data. Many of the yeast profiles in BeerSmith have not been updated with the latest specs from the yeast suppliers so the first thing I would check is if the profiles for the yeasts you use are up to date.

For your Altbier example, do you have simple sugars in your recipe? This will raise the apparent attenuation, since simple sugars ferment completely and attenuation ranges are based upon using an all malt wort.

If you find that your attenuation is consistently off and correlates to your mash temperature, you can adjust the fermentability based upon mash temperature in the 'options' > 'advanced' section. Make sure that your data is pretty conclusive before you adjust these parameters.

Personally, I have never had an issue with the calculation of estimated apparent attenuation in my copy of BeerSmith. It is usually pretty close to the measured attenuation.
 
Might be your mash profile. BS3 does take mash temp into account in estimating attenuation.

I just tried that yeast it gave me 77.6 for estimated attenuation with my current mash profile on a previous recipe. I then changed the mash profile to "single infusion, light body, no mash out" and BS3 estimated 82.7. Then I changed to a Hochurz mash that I designed and it estimated 87%. This was all malt recipe with sugar or adjuncts it would have estimated even higher attenuations.
 
eric19312 said:
Might be your mash profile. BS3 does take mash temp into account in estimating attenuation.

I just tried that yeast it gave me 77.6 for estimated attenuation with my current mash profile on a previous recipe. I then changed the mash profile to "single infusion, light body, no mash out" and BS3 estimated 82.7. Then I changed to a Hochurz mash that I designed and it estimated 87%. This was all malt recipe with sugar or adjuncts it would have estimated even higher attenuations.
Click to expand...


This is a good point! The model for attenuation in BeerSmith is really based upon a single point saccharification rest. Doing step mashes always seems to mess up the prediction of FG and attenuation. I've learned to ignore the estimates for fermentation when I have done step mashes with multiple rests within the activity range of the amylase enzymes.
 
Oginme said:
This is a good point! The model for attenuation in BeerSmith is really based upon a single point saccharification rest. Doing step mashes always seems to mess up the prediction of FG and attenuation. I've learned to ignore the estimates for fermentation when I have done step mashes with multiple rests within the activity range of the amylase enzymes.
Click to expand...

So I changed from a BIAB multi step mash profile to a BIAB single temp infusion in the BS3 recipe for this Altbier. The estimated attenuation dropped to 81.5%, which is still higher than what WhiteLabs has listed for the attenuation range for this yeast.

This is a AG recipe....no adjucts or simple sugars.

I've consistently hit the estimated OG numbers with various recipes in BS3, Ive never hit the estimated FG with any of them though. Going back through the session logs of these, the estimated attenuation was higher than what the yeast manufacture has as its stated attenuation range. I just dont understand why BS3 does this, or how I can manipulate it so that the estimates are more realistic.

I'll pull some data together and try to share with the group.
 
CJnCincy said:
I'll pull some data together and try to share with the group.
Click to expand...

So here is the data...the good, the bad, but mostly the ugly.
Style Yeast BS3 Est. Atten Actual Atten Manf Est Actual
Dunkelwiezen Schneider 86.3 77.6 75-82 No Yes
Hefeweizen v1 Schneider 81.2 66.9 75-82 No No
Dunkelwiezen SchneiderC 81.2 68.4 75-82 No No
Kolsch WLP003 86.7 67.4 73-80 No No
Kolsch WLP003 86.7 75.2 73-80 No Yes
Wet Hops Pale WLP060 82.3 77.8 72-80 No Yes
Hefewiezen2 WLP351 86.4 80.1 75-82 No Yes
Hefeweizen v3 WLP351s1 76 68.5 75-82 Yes No
Witbier WLP400 86.1 73.2 74-78 No No
Dunkel v2 WLP833s1 81.7 72.3 70-76 No Yes
Maibock WLP833s3 81.5 72.4 70-76 No Yes
Dopplebock WLP835 59 69.3 70-76 No No
Helles v1 WLP835s2 81.8 70 70-76 No Yes
Bock WLP860s3 70.6 77.5 68-72 Yes No
Mexican Lager WLP940 85.4 68.6 70-78 No No
Grodzieski WY1007 85.3 71 73-77 No Yes
Helles WY2308 83.9 72 70-74 No Yes
Vienna WY2487 78.1 68.6 70-74 No No
Belgian Pale WY3522 75 69.1 72-76 Yes No
Belgian Dubbel WY3522c 74.8 81 72-76 Yes No

Notable:
BS3 Estimated Attenuation was outside the manufacturers' stated range 16/20 times.
 
TBH if you are using BS3 to check to see if your beer is going to fall in the style just ignore FG and ABV estimates.

Focus on OG, IBU, SRM and then use a style appropriate yeast and mash temperature. When you rebrew with same yeast consider your previous actual results and adjust OG and mash parameters to nudge the beer in the direction you want to take it.
 
You
eric19312 said:
TBH if you are using BS3 to check to see if your beer is going to fall in the style just ignore FG and ABV estimates.

Focus on OG, IBU, SRM and then use a style appropriate yeast and mash temperature. When you rebrew with same yeast consider your previous actual results and adjust OG and mash parameters to nudge the beer in the direction you want to take it.
Click to expand...

You are correct. My attenuation is typically on the low end, or slightly off the mark of the manf. stated attenuation. I do make yeast starters and use a stir plate. My fermentation is temp controlled. Maybe I'm making more of this than I need to, or trying to nail down a wide varible, but I cant understand why my attenuation is so far off of the BS3 estimate.

FWIW
AG brewing only (used adjuncts only in the Mexican and Belgian Styles)
BIAB (Clawhammer Supply 120v, 10gal) system
Multi-step mashing to increase mash efficiency
Mash efficiency ranges between 75-85%. (last 10 brew sessions).
 
^ There are a lot of factors that go into attenuation, but just eyeballing those numbers, a lot of them are just really very low for the styles.

That said, I would not generally expect attenuation in Beersmith (and most programs) to be very close all the time. It doesn't consider makeup of the grain bill in its attenuation calculations.
 
I guess I'm at a loss for understanding the lower attenuation in my operation. I do use multi-step mashing almost exclusively. I use yeast starters ~ 1.5L, have a temp controlled fermentation chamber, and aerate. I should be killing it on attenuation, but I'm typically at the bottom, or lower than what the yeast manf. states as the attenuation range. I just can't figure it out.
 
I've had similar issues, so here are a couple relevant questions:

When you say you are aerating, what exactly are you doing?
What is your mash pH and what is the pH at the end of the boil?
What is your calcium level in your water and what level are you targeting?
Are you using yeast nutrient, specifically zinc?
 
Thanks in advance for the help. I really appreciate it. My answers are below?

When you say you are aerating, what exactly are you doing?
Current method: Pure Oxygen, 1 minute, through aeration stone.

What is your mash pH and what is the pH at the end of the boil?
Typically take a mash PH reading when I begin the beta-amalyse rest. Last 5 reading have been: 5.4, 5.3, 5.3, 5.4, 5.5 I use a combination of aciduated malt and lactic acid to achieve this. My water is very high in biocarbonates (384). I sometimes cut it 50% with distilled water depending on the beer style. Ive never done a PH reading at the end of boil.

What is your calcium level in your water and what level are you targeting? My water starts at 96. I don't have a particular target. I add calcium chloride per BS3 recommendations as appropriate per style.

Are you using yeast nutrient, specifically zinc? I typically use either Servomyces or WLN1000.
 
CJnCincy said:
I guess I'm at a loss for understanding the lower attenuation in my operation.
Click to expand...

Long shot... you're not, by any chance, using a refractometer, are you? If so, are you correcting the readings with a refractometer calculator?
 
Good info, two thoughts:

I don't think 1min of O2 is long enough to get good levels in the wort, especially for lagers. Over years of trial and error, I like 5-6 minutes of O2 at .5LPM. I'm using a 2 micron stone, and I suspect I could get better DO levels if I was using a .5 micron stone, but that 5min seems to net me 9-10ppm DO, so I'm ok with that. I've noticed that if I am foaming the wort, the O2 is not dissolving as efficiently and I need to lower my flow rate.

Adding a little acid at the end of the boil (I use lactic) to drop the pH to the 5-5.1 range will help the yeast out getting started. They naturally will need to drop the pH to start fermentation, so I like to help them along.
http://braukaiser.com/wiki/index.php/How_pH_affects_brewing#Nutrient_uptake_by_yeast

Of the two, I think that O2 deficiency might be the cause of your under-attenuation issues. It should be easy for you to test out, though I'm not sure if you have a flow meter to determine how much O2 you are pushing. If you don't have one you could just try and eyeball it and if you are foaming, its likely too fast.

Cheers,
Joe
 
RiverCityBrewer said:
Good info, two thoughts:

I've noticed that if I am foaming the wort, the O2 is not dissolving as efficiently and I need to lower my flow rate.

Adding a little acid at the end of the boil (I use lactic) to drop the pH to the 5-5.1 range will help the yeast out getting started. They naturally will need to drop the pH to start fermentation, so I like to help them along.
http://braukaiser.com/wiki/index.php/How_pH_affects_brewing#Nutrient_uptake_by_yeast
Click to expand...

I'll def try this with the Baltic Porter that is on deck for this weekend. For O2, I hit it until I see it bubble up (so I know it is working), then back it off....but still see the wort moving. I use the disposable O2 tanks from ACE Hardware. Maybe its time to invest in an O2 tank?
 
CJnCincy said:
Using a refractometer now....my hydrometer broke :( Whats a refractometer calculator?
Click to expand...


BS3 has one built in. You need to tell it you are using a refractometer to measure gravity of fermenting beer and it needs to know what the OG was. It will get you within a few SG points of right. You should replace your hydrometer and ideally get a FG hydrometer they are awesome. I have one like this: https://www.morebeer.com/products/final-gravity-hydrometer.html - I use my refreactometer on brew day for everything up to and including FG. Then I use the refractometer and the BS3 calculator for monitoring fermentation. But for FG I always use hydrometer.
 
CJnCincy said:
Using a refractometer now....my hydrometer broke :( Whats a refractometer calculator?
Click to expand...

When using a refractometer, both the OG and FG readings have to be adjusted.

The OG reading has to be adjusted because refractometers are calibrated for Sucrose solutions, which beer wort mostly isn't. In the case of OG, the error is fairly small.

The FG reading has to be adjusted, for the same reason as OG, -plus- the presence of alcohol severely skews the reading (alcohol has a refractive index that's different from water). The FG error is quite large.

A refractometer calculator takes both readings as input (it can't figure out FG without the OG) and corrects them.
 
Last edited:
Sounds like you have the nutrient taken care of and I would think 1 min pure O2 through a stone would at least get you in ballpark.

Here are some other thoughts on fixing chronically low attenuation issue:
  • Have you checked the calibration of your mash thermometer? I figured out this weekend my RTD is reading about 4 degrees low. That is enough to produce a less fermentable wort.
  • Are you mashing long enough? For a highly fermentable wort I like 148F for 90 minutes followed by a ramp to 160, hold for 15 min then ramp to 169F.
  • Are you pitching enough yeast on those lagers? 1.5 Liter starter might just not be enough yeast.
  • You mention you do have fermentation temperature control. Are you trying to ferment too cold? Perhaps start higher in the optimal range and bump up at end to finish at the top end of the range.
  • Sort of contrary to previous point but are you actually holding the temperature of the beer steady during fermentation? Data from a Tilt hydrometer can be helpful here. I even used an RC-4 temperature logger for a while to diagnose a temperature control issue I was having (big swings in first couple days of fermentation).
 
eric19312 said:
Sounds like you have the nutrient taken care of and I would think 1 min pure O2 through a stone would at least get you in ballpark.

Here are some other thoughts on fixing chronically low attenuation issue:
  • Have you checked the calibration of your mash thermometer? I figured out this weekend my RTD is reading about 4 degrees low. That is enough to produce a less fermentable wort.
  • Are you mashing long enough? For a highly fermentable wort I like 148F for 90 minutes followed by a ramp to 160, hold for 15 min then ramp to 169F.
  • Are you pitching enough yeast on those lagers? 1.5 Liter starter might just not be enough yeast.
  • You mention you do have fermentation temperature control. Are you trying to ferment too cold? Perhaps start higher in the optimal range and bump up at end to finish at the top end of the range.
  • Sort of contrary to previous point but are you actually holding the temperature of the beer steady during fermentation? Data from a Tilt hydrometer can be helpful here. I even used an RC-4 temperature logger for a while to diagnose a temperature control issue I was having (big swings in first couple days of fermentation).
Click to expand...

Thanks for this!

I'm going to check the calibration of my thermoprobe right now. I'll see how it matches the thermometer I use with my smoker/bbq as well as a thermopen I also have.

My step mashes are typically 1-2hrs long.

My cellar holds at 60-62. Ive used this ambient temp for my Hefe's, Kolsch, Grodziskie, and Altbier. My lagers I have the temp controller set at 52 using a thermowell.
 
@CJnCincy Before you go off on a wild goose chase, check your readings with a refractometer calculator. It's almost certainly the issue here. i.e. there likely is no issue, other than measurement interpretation.
 
VikeMan said:
@CJnCincy Before you go off on a wild goose chase, check your readings with a refractometer calculator. It's almost certainly the issue here. i.e. there likely is no issue, other than measurement interpretation.
Click to expand...

So using the Northern Brewer calculator https://www.northernbrewer.com/pages/refractometer-calculator and the readings from the Kolsch I just kegged yesterday, I discovered this:

The measured FG on the refractometer from yesterday's kegging was 1.022 (6 Brix).

Using the above calculator, and converting my original gravity reading (.1050) to Brix (12.5), I found the calculator stating my FG as 1.007.

I had no idea a refractometer calculator even existed.

Now I'm curious if I've never had a problem with attenuation this whole time?

Still checking on my thermometer calibration....will report back soon.
 
Yup you nailed it @VikeMan

@CJnCincy do you use desktop or mobile BS3?

In the mobile version there is a tool you are probably already using to convert brix to SG. At the top of that tool there is a drop down menu with three choices: Unfermented Wort Gravity (default choice), Fermenting Wort Gravity, OG of finished beer. You want to use Fermenting Wort Gravity for checking FG and you have to know what your OG was to get the right number.

In the desktop version the tool is similar and there are also shortcuts to the tool in the recipe/session tab that automatically select whether you are measuring unfermented wort or fermenting wort. These are really nice little shortcuts and sadly missing from the iOS version of the software.
 
eric19312 said:
Yup you nailed it @VikeMan

@CJnCincy do you use desktop or mobile BS3?
Click to expand...

I use the desktop version. Ive seen the refractometer icon, but never knew what it was or used it. I just assumed it didn't mean anything (never clicked on it).

Thats why this forum is great....learn something new all the time!!!!

Still checking my thermo calibration though.....now that I'm curious about it.
 
CJnCincy said:
I use the desktop version. Ive seen the refractometer icon, but never knew what it was or used it. I just assumed it didn't mean anything (never clicked on it).

Thats why this forum is great....learn something new all the time!!!!

Still checking my thermo calibration though.....now that I'm curious about it.
Click to expand...

I believe you could go back and figure out what your attenuations really were.

Leave the tool set to unfermented wort, then put in different values for brix until you find the brix that gives you the specific gravity you listed.

Then change the tool to fermenting wort, enter your OG (best if from your notes, but worth trying just from the recipe if need be) and the brix and you should have a your corrected FG.

I think this paper exercise would give you a sense of where you are with attenuation. Based on the number of beers you have made you must be doing something right or you would of quit by now. A lot of those results you posted before sound like they would be undrinkable yet I see you repeating the same recipe three times in a row so am guessing they were not dumpers.
 
eric19312 said:
I believe you could go back and figure out what your attenuations really were.

Leave the tool set to unfermented wort, then put in different values for brix until you find the brix that gives you the specific gravity you listed.

Then change the tool to fermenting wort, enter your OG (best if from your notes, but worth trying just from the recipe if need be) and the brix and you should have a your corrected FG.

I think this paper exercise would give you a sense of where you are with attenuation. Based on the number of beers you have made you must be doing something right or you would of quit by now. A lot of those results you posted before sound like they would be undrinkable yet I see you repeating the same recipe three times in a row so am guessing they were not dumpers.
Click to expand...

I've had some dumpers (scorched heating element). Never had any that were overly sweet or cloying ..... and to date, no off flavors. (Hopefully I didnt just jinx myself).
 
So I measured my brewhouse thermometer against both a Thermopen and a digital thermometer I use for smoking/bbq. The results were interesting.

@ 100F and 125F all three read the same
@ 150F, brewhouse was 1 deg less than both other thermometers
@ 175F, brewhouse was 2 deg less than both thermometers
@ 200F, brewhouse was 3 deg less than both termometers

Since mash-out temp is typically around 170F, this probably isnt a big deal?
 
CJnCincy said:
So I measured my brewhouse thermometer against both a Thermopen and a digital thermometer I use for smoking/bbq. The results were interesting.

@ 100F and 125F all three read the same
@ 150F, brewhouse was 1 deg less than both other thermometers
@ 175F, brewhouse was 2 deg less than both thermometers
@ 200F, brewhouse was 3 deg less than both termometers

Since mash-out temp is typically around 170F, this probably isnt a big deal?
Click to expand...

I certainly wouldn't expect any major attenuation issues based on these results.
 

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