Author Topic: ABV change when scaling recipe  (Read 3950 times)

Offline critterz

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ABV change when scaling recipe
« on: December 18, 2013, 07:26:01 PM »
I made a all grain Prairie Oatmeal Stout (very good BTW).  When drinking it, the beer seemed to be a low alcohol (which is fine with me).  When I checked my Beersmith software it said the ABV was .6% (point six percent).  I checked the original recipe and it says it is 5.7%.  I scaled the recipe using my Beersmith software from 5 gallon batch to a 3.75 gallon batch (I only have a 4 gallon pot).  I didn't check SG.  Why did the alcohol content change so drastically?

Offline Scott Ickes

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Re: ABV change when scaling recipe
« Reply #1 on: December 18, 2013, 07:30:19 PM »
I'd ask if you used yeast, but that would be me just trying to be funny.

Actually, you really need to give us a lot more information than you have given us.  Can you post your recipes (both the 5 gallon version and the 3.75 gallon version) so that we can look for discrepencies.
Kegs:
 Red IPA
 ESB
 Saison Solera
 Dubel (Aged in Malbec Wine Barrel
Aging:
 80 Shilling (In bourbon barrel)
Bottled
 Peppermint Patty Stout
 Wee Heavy

Scott Ickes
https://creativebrewing.wordpress.com

Offline critterz

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Re: ABV change when scaling recipe
« Reply #2 on: December 18, 2013, 07:54:43 PM »
Scaled recipe:
4 lbs 6.2 oz Pale Malt (2 Row) US
1 lbs 4.1 oz Oats, Flaked
10.0 oz Caramel/Crystal Malt - 10L
5.0 oz Cara-Pils/Dextrine
4.8 oz Chocolate Malt
4.8 oz Roasted Barley
2.5 oz Barley, Flaked
2.4 oz Black (Patent) Malt
0.58 oz Northern Brewer [8.50 %] - Boil 60.0 min
0.58 oz Cluster [7.00 %] - Boil 15.0 min
1 pkg Irish Ale (Wyeast Labs #1084) [125.05 ml] Yeast 11 -
0.60 oz Fuggles [4.50 %] - Dry Hop 3.0 Days

Original recipe:
7 lbs    Pale Malt (2 Row) US
2 lbs    Oats, Flaked
1 lbs    Caramel/Crystal Malt - 10L
8.0 oz    Cara-Pils/Dextrine
8.0 oz    Chocolate Malt
8.0 oz    Roasted Barley
4.0 oz    Barley, Flaked
4.0 oz    Black (Patent) Malt
1.0 oz    Northern Brewer [8.5%] - Boil 60 min    
1.0 oz    Cluster [7.0%] - Boil 15 min    
1 pkgs    Irish Ale (Wyeast Labs #1084)    
1.0 oz    Fuggles [4.5%] - Dry Hop 3 days

Thanks!

Offline Scott Ickes

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Re: ABV change when scaling recipe
« Reply #3 on: December 18, 2013, 08:24:06 PM »
I wasn't able to reproduce your .6%.  I did find that the scaling wasn't proportional, so the 5 gallon recipe and the 3.75 gallon recipe won't reproduce the exact same beer.  I plugged in your numbers for the 5 gallon batch and scaled it down with beersmith and some of the grains were high and some were low compared to your 3.75 gallon version and my beersmith scaled 3.75 gallon version. 

When I just typed in your two recipes as you supplied them, the scaled down recipe was at 5.3% ABV and the 5 gallon batch was above 6% ABV.  However, I don't know if you have your batch size set at 5 gallons exactly or at 5.5 gallons.  I always set my batch size at 5.5 gallons, knowing that I'll lose some volume during fermentation.  I always want 5.5 gallons going into my fermentor.

Something is drastically amiss, if you're getting .6% for estimated ABV. 

Screen shots might help.
Kegs:
 Red IPA
 ESB
 Saison Solera
 Dubel (Aged in Malbec Wine Barrel
Aging:
 80 Shilling (In bourbon barrel)
Bottled
 Peppermint Patty Stout
 Wee Heavy

Scott Ickes
https://creativebrewing.wordpress.com

Offline brewfun

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Re: ABV change when scaling recipe
« Reply #4 on: December 19, 2013, 06:35:13 AM »
I'm wondering if the smaller recipe Type is set as "Extract" instead of All Grain.
Beer Appreciation is the space between pints.

Offline Scott Ickes

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Re: ABV change when scaling recipe
« Reply #5 on: December 19, 2013, 11:14:25 AM »
Brewfun...Good thought...We'll see if that was it...
Kegs:
 Red IPA
 ESB
 Saison Solera
 Dubel (Aged in Malbec Wine Barrel
Aging:
 80 Shilling (In bourbon barrel)
Bottled
 Peppermint Patty Stout
 Wee Heavy

Scott Ickes
https://creativebrewing.wordpress.com

Offline Bajaedition

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Re: ABV change when scaling recipe
« Reply #6 on: December 19, 2013, 12:08:04 PM »
he should have 4 pounds 14.4 ozs of malt and 1 pound 6.4 oz of the flaked oats
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