Author Topic: Higher ABV than desired  (Read 1359 times)

Offline x3la

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Higher ABV than desired
« on: July 15, 2020, 10:03:53 AM »
I've brewed an English Bitter to the exact same recipe twice now. Both times, the estimated ABV was 3.6% in BeerSmith -- this matches the beer I'm 'cloning'. I have consistently hit 4.5% with both batches. I want to explore my options for the next batch, to bring it down to the desired 3.6%.

The yeast I'm using is Ringwood WPL005 from a home made slant. BeerSmith shows this as having a max attenuation of 74% and this indeed matches the characteristics listed on White Labs for this yeast: https://www.whitelabs.com/yeast-bank/wlp005-british-ale-yeast

Currently, in the Primary fermenter, 6 days into fermentation I have 85% attenuation.

Looking at my graph (attached) I see that I hit my target ABV 2 days ago when the attenuation was at 65%.

What should I do for my next batch to try and get the ABV to ~3.5% ?

Is the issue entirely with the high attenuation?

Should I reduce my grain bill?

Should I adjust the yeast in the tab so that the max attenuation is 85% ? In doing so, will the grain bill dynamically adjust to ensure 3.5% is hit?

If I transfer into Secondary when the ABV is close to 3.5% next time, will this slow the fermentation enough to stall it around my desired ABV?

Offline Oginme

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Re: Higher ABV than desired
« Reply #1 on: July 15, 2020, 11:25:07 AM »
What is your grain bill?  It is hard to troubleshoot without all the information on the recipe. 

The published yeast attenuation max/min are really specification range for that yeast on a standard laboratory wort.  Actual apparent attenuation can be affected by mash temperature, type of malts used, simple sugars, fermentation temperatures, and yeast health along with other things. 

Transferring the wort to a secondary or trying to stop fermentation prematurely will result in having unfermented sugars in your bottles/kegs/packaging which could lead to bottle bombs, uncontrolled carbonation, and heavy foaming when trying to dispense.  IMHO, it is always better to let the yeast finish out so that packaging can be stable.

If you want us to look at your recipe, export it as a .bsmx file and post it here so we can see just how your recipe is constructed and your process surrounding it.

You can export a recipe by highlighting it in the file (do not open), clicking on 'file' > 'export selected' and then saving the file.
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Offline x3la

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Re: Higher ABV than desired
« Reply #2 on: July 15, 2020, 11:45:33 AM »
Thanks! Recipe attached

Offline brewfun

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Re: Higher ABV than desired
« Reply #3 on: July 15, 2020, 11:58:34 AM »
The 90 minute mash at 152 left you with a very fermentable wort. In making low abv beer I used to find the body and flavor lacking when I went for fermentability and all malt grists. I've learned to use much higher mash temps and go for about 1% abv fermentability. The other 2.5% abv. come from an invert sugar addition. Sometime last year I heard a podcast with Ron Pattinson talking about post WWII cask ale where he confirmed that breweries were using this technique well into the 70's.
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Offline x3la

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Re: Higher ABV than desired
« Reply #4 on: July 15, 2020, 02:04:56 PM »
The 90 minute mash at 152 left you with a very fermentable wort. In making low abv beer I used to find the body and flavor lacking when I went for fermentability and all malt grists. I've learned to use much higher mash temps and go for about 1% abv fermentability. The other 2.5% abv. come from an invert sugar addition. Sometime last year I heard a podcast with Ron Pattinson talking about post WWII cask ale where he confirmed that breweries were using this technique well into the 70's.

Presumably the consequence of Rationing. I recently read one of his blogs which has a Grist chart from Fullers which shows the fermentable ingredient variations in Pride over the years. Quite interesting!

https://www.beeradvocate.com/articles/16373/fullers-london-pride-a-variable-veritable-classic/

Offline x3la

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Re: Higher ABV than desired
« Reply #5 on: July 15, 2020, 02:27:28 PM »
The 90 minute mash at 152 left you with a very fermentable wort. In making low abv beer I used to find the body and flavor lacking when I went for fermentability and all malt grists. I've learned to use much higher mash temps and go for about 1% abv fermentability. The other 2.5% abv. come from an invert sugar addition. Sometime last year I heard a podcast with Ron Pattinson talking about post WWII cask ale where he confirmed that breweries were using this technique well into the 70's.

Isn't the effect of mash time factored into BeerSmith's calculations for estimated ABV? It presumably knows my 90 minute mash will have a higher wort fermentability than a 60 minute mash?

Offline Oginme

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Re: Higher ABV than desired
« Reply #6 on: July 15, 2020, 05:31:30 PM »
BeerSmith models the affect of mash temperature but not time.  I can't remember seeing any mash fermentability models which take time into account, though I am sure that someone has taken a poke at it. 
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Offline x3la

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Re: Higher ABV than desired
« Reply #7 on: July 15, 2020, 06:07:18 PM »
BeerSmith models the affect of mash temperature but not time.  I can't remember seeing any mash fermentability models which take time into account, though I am sure that someone has taken a poke at it.

Should my next batch be an experiment with mash time then? 60 minutes rather than 90?

Offline Oginme

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Re: Higher ABV than desired
« Reply #8 on: July 15, 2020, 06:19:07 PM »
If you are willing to do a series to determine just what your process will produce, that would be an excellent way to do it.  You can apply the learning to any recipes you try later. 
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Offline brewfun

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Re: Higher ABV than desired
« Reply #9 on: July 16, 2020, 07:50:44 AM »
Should my next batch be an experiment with mash time then? 60 minutes rather than 90?

If you do a search for mash conversion experiments, you'll find that it happens in 40 minutes or less. The major factors are water volume, calcium level and pH which when in synchronicity will convert in 15 to 20 minutes. After 40 minutes, there is continued breakdown of dextrine and protein, which will lead to lower FG. However, it's hardly linear and doesn't always warrant the time in styles that need more body.

The homebrew adherence to a long mash is due in part to pro techniques where 4 vessel systems are built around process times for consistency and efficiency, rather than "styles." Thus, the "style," or more likely house character, is flexible based on equipment and sales.

I've done a few time experiments on my brewhouses and each has its own sweet spot. The one I use the most makes its best wort at 150F for 50 minutes after dough in. A new fully automated 30 bbl brewhouse seems to be on rails at 156 for 30 minutes, but the mash is continuously stirred. In both cases, there's a mashout step. By contrast, a 5 bbl system I started using a couple of months ago needs multiple steps lasting 2 hours or else there's a very slow lauter.
« Last Edit: July 20, 2020, 08:50:53 AM by brewfun »
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Offline x3la

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Re: Higher ABV than desired
« Reply #10 on: July 16, 2020, 12:01:24 PM »
This is an experiment to effectively try to decrease my mash efficiency by reducing the time.

It wouldn't be better to reduce the grain bill slightly and always strive for maximum mash efficiency?

Offline x3la

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Re: Higher ABV than desired
« Reply #11 on: July 16, 2020, 12:09:59 PM »
The 90 minute mash at 152 left you with a very fermentable wort. In making low abv beer I used to find the body and flavor lacking when I went for fermentability and all malt grists. I've learned to use much higher mash temps and go for about 1% abv fermentability. The other 2.5% abv. come from an invert sugar addition. Sometime last year I heard a podcast with Ron Pattinson talking about post WWII cask ale where he confirmed that breweries were using this technique well into the 70's.

What mash temp do you target for English Ales?

https://byo.com/article/successful-mash-conversion-tips-from-the-pros/

"If your mash conversion temperature exceeds 153? F, a higher percentage of unfermentable sugars, called dextrins, will be produced. A higher level of dextrins occurs if your grain bill contains a good amount of caramel and caramalts, which are inherently high in these dextrins (14 percent to 18 percent). These dextrins are unfermentable and therefore will raise the final gravity and lower the alcohol percentage of the beer.

I like to use a slightly higher mash conversion temperature when producing maltier styles of beer to utilize the dextrins that add body and mouthfeel to the beer."

Offline Oginme

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Re: Higher ABV than desired
« Reply #12 on: July 16, 2020, 01:14:59 PM »
It really depends upon the style.  For bitters, pale ales, golden ales, IPAs I am in the 152F range.  For milds, browns, porters I am anywhere from 152 to 160 depending upon the style and my goals for body and flavor.
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Offline x3la

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Re: Higher ABV than desired
« Reply #13 on: July 16, 2020, 08:28:47 PM »
If you are willing to do a series to determine just what your process will produce, that would be an excellent way to do it.  You can apply the learning to any recipes you try later.

What would my alternatives be? I know that the brewery that created what I'm trying to reproduce use a 90 min mash.
« Last Edit: July 16, 2020, 11:27:04 PM by x3la »

Offline Oginme

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Re: Higher ABV than desired
« Reply #14 on: July 17, 2020, 02:48:39 AM »
Alternative would be to increase your mash temperature and stick with the 90 minute mash.

Note the advice that Brewfun gave, every process is a bit different.  For my systems, I switched a year ago from doing full volume BIAB to using an all-in-one Anvil Foundry.  Same crush, same grains, same basic process of full volume mash and my mash efficiency dropped about 8 points and my wort was less fermentable.  I changed my crush a bit and increased the mash time to gain back 6 of those points and achieved the same basic fermentability as I had previously.  I could increase my mash time more to get another point or two of efficiency, but would also produce a much more fermentable wort (tried it twice and it worked the same way both times).  So I backed down to where I felt comfortable in my results and what matched my brew day schedule. 

So if a brewery mashes for 90 minutes on a recipe I wanted to mimic, I would take a look at the results and adjust my mash temperature to get the same predicted final gravity (measure of fermentability) as the big brewery and keep my mash schedule as a constant.  It does not mean that keeping the mash temperature the same and adjusting the mash time is wrong. In fact it is just as valid, but just not how I chose to adapt the brewery practice to my system to achieve what I hope would be the same result.
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