Calculating weight from grain bill % - Home Brew Forums

 Home Brew Forums > Calculating weight from grain bill %

01-14-2011, 06:20 AM   #1
jimbus
Recipes

Jun 2010
Posts: 52
Liked 11 Times on 2 Posts

Can someone help me with this...Im looking to brew a 5 gallon batch of this Kate the Great clone but only have the percent composition of each grain in the total grist. How do you go about calculating how many pounds of each grain are needed for this sized batch?

When we brew a batch of Kate we use 77% Pale malt, 2% Crystal 45, 1% Caramel 120, 1% Chocolate malt,1% Black malt, 3% Carafa DH# 3 (Weyerman),3.5% Wheat malt 3.5% Flaked Barley, 2% Roasted malt,3.5% Special B, 2.5% Aromatic.

01-14-2011, 06:38 AM   #2
Recipes

Aug 2009
NW
Posts: 1,630
Liked 29 Times on 23 Posts

Use a recipe program like beercalculus or promash.

01-14-2011, 06:52 AM   #3
Frodo
Recipes

Nov 2009
, AK
Posts: 1,034
Liked 28 Times on 27 Posts

You can calculate it by hand, but it requires some math labor, especially with that many grains. The software programs have the calculations built in. You'll need to know what your brewhouse efficiency is as well. You'd just enter all the grains in the software then play around with the amounts until the percentages are right.

01-14-2011, 07:02 AM   #4
jimbus
Recipes

Jun 2010
Posts: 52
Liked 11 Times on 2 Posts

ok i just tried messing around with beersmith (i've never used it before) and i was able to add all the grains and tweak them to the correct percentages, with a 70% efficiency...only problem is that its telling me I need about 40lbs of grain for a 5.0gal batch! Also, I noticed that it locked in the boil volume at 5.87gal (when I would really want it to be 6.5gal) and it calculated my OG to be 1.199 when its supposed to be 1.104 ...help?

01-14-2011, 07:16 AM   #5
HItransplant
Recipes

Aug 2010
Portlandia
Posts: 1,033
Liked 8 Times on 7 Posts

Quote:
 Originally Posted by jimbus ok i just tried messing around with beersmith (i've never used it before) and i was able to add all the grains and tweak them to the correct percentages, with a 70% efficiency...only problem is that its telling me I need about 40lbs of grain for a 5.0gal batch! Also, I noticed that it locked in the boil volume at 5.87gal (when I would really want it to be 6.5gal) and it calculated my OG to be 1.199 when its supposed to be 1.104 ...help?
your OG is probably high because you have 40# of grain in the recipe.

can you decrease the amount of grain? Remember, the % is relative... in other words, you can have 90# pale malt and 10# roasted, or 9# and 1# respectively... either way, you have 90% pale malt.

I cant help more since I dont use beersmith... maybe someone who does will recognize something more specific to the program.
__________________
Quote:
 Originally Posted by BlindLemonLars It's comfort foam. :D
Quote:
 Originally Posted by EdWort It's a gentle recipe, so your first time will be enjoyable and memorable. :D

01-14-2011, 01:14 PM   #6
dzlater
Recipes

Apr 2008
New Jersey
Posts: 1,098
Liked 38 Times on 34 Posts

The math is really pretty easy.

Grain bill

original target gu * total volume = total gu

% of fermentable * total gu = gu of fermentable

gu of fermentable / extract potentail / % effciancy = lbs

01-14-2011, 01:18 PM   #7
Oldsock

Recipes

Sep 2007
DC, Washington DC
Posts: 3,237
Liked 256 Times on 169 Posts

Cool, I'd always wondered what was in that beer. I was also under the impression they used some brown sugar.
__________________
Check out The Mad Fermentationist for my adventures in fermentation and my book: American Sour Beers!

Wulfman Likes This
01-14-2011, 01:22 PM   #8
jgourd
Recipes

Feb 2010
Louisiana
Posts: 864
Liked 47 Times on 31 Posts

Grab my brewsheet. It's in OpenOffice format but recent versions of MS Excel will open it just fine. Go to the last sheet (useful formulas) and take a look at the Batch Scaling section. It will let you input your desired OG, batch size, brewhouse efficiency, grains, and grain %. It will compute the amount (weight) of each grain for your specifications. I use it all the time to convert recipes for my system.

01-14-2011, 01:29 PM   #9
Oldsock

Recipes

Sep 2007
DC, Washington DC
Posts: 3,237
Liked 256 Times on 169 Posts

Here are my back of the envelop numbers. Most breweries just do grainbills as a straight percentage by weight, not based on the percent of extract (which I only use for sugar additions).

@70% Efficiency OG 1.104
77% - Pale - 18.5 lbs
3.5% Wheat Malt - .84 lbs
3.5% Flaked Barley - .84 lbs
3.5% Special B - .84 lbs
3% Carafa Special III - .75 lbs
2.5% Aromatic - .6 lbs
2% Roasted - .5 lbs
2% C45 - .5 lbs
1% C120 - .25 lbs
1% Chocolate - .25 lbs
1% Black - .25 lbs
Brown Sugar ?

Looks pretty reasonable to me, 1.75 lbs of dark malt, about the same of crystal.

I'd probably brew it and expect 65% efficiency due to the large grainbill, and get the remaining ~.007 from unrefined brown sugar.
__________________
Check out The Mad Fermentationist for my adventures in fermentation and my book: American Sour Beers!

01-14-2011, 04:21 PM   #10
jimbus
Recipes

Jun 2010
Posts: 52
Liked 11 Times on 2 Posts

Quote:
 Originally Posted by jgourd Grab my brewsheet. It's in OpenOffice format but recent versions of MS Excel will open it just fine. Go to the last sheet (useful formulas) and take a look at the Batch Scaling section. It will let you input your desired OG, batch size, brewhouse efficiency, grains, and grain %. It will compute the amount (weight) of each grain for your specifications. I use it all the time to convert recipes for my system.
thanks for this, looks pretty handy. And thanks to oldstock for the numbers.

What does "GU" stand for in the previous formula?