Calculating weight from grain bill %

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.

Use a recipe program like beercalculus or promash.

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.

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?

jimbus said:

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?

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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.

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

Cool, I'd always wondered what was in that beer. I was also under the impression they used some brown sugar.

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.

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.

jgourd said:

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.

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thanks for this, looks pretty handy. And thanks to oldstock for the numbers.

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

If you want to do it in beersmith, there is a button to adjust the Gravity while keeping the given percentages the same. That way, you can input 40 lbs of grain (or whatever) to get your percentages, and then just scale down the gravity to a more appropriate number.

That's exactly what I was trying to do but couldn't figure out how. I'll take a look again, thanks.

jimbus said:

And thanks to oldstock for the numbers.

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

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No problem, I might have to brew it as well...

GU is gravity units (a 1.104 beer would have 104 GU). Many brewers think in plato because doing math with it isn't as clumsy (I started with gravity and have stuck with it).

jgourd said:

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.

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hey thanks for sharing.. Ill poach that too

This is what I came up with in Beersmith for a 5.5 gal batch at 70% efficiency...any thoughts on the discrepancies from Oldstock's numbers? or are they negligible?

17.75 lb Pale Malt (2 Row) US (2.0 SRM) Grain 77.0 %
0.80 lb Barley, Flaked (1.7 SRM) Grain 3.5 %
0.80 lb Special B Malt (180.0 SRM) Grain 3.5 %
0.80 lb Wheat Malt, Dark (9.0 SRM) Grain 3.5 %
0.70 lb Carafa III (525.0 SRM) Grain 3.0 %
0.60 lb Aromatic Malt (26.0 SRM) Grain 2.5 %
0.50 lb Caramel/Crystal Malt - 40L (40.0 SRM) Grain 2.0 %
0.50 lb Roasted Barley (300.0 SRM) Grain 2.0 %
0.25 lb Black (Patent) Malt (500.0 SRM) Grain 1.0 %
0.25 lb Caramel/Crystal Malt -120L (120.0 SRM) Grain 1.0 %
0.25 lb Chocolate Malt (350.0 SRM) Grain 1.0 %

Pretty small difference relatively speaking, and probably due to difference in the extract potential for each grain in BeerSmith vs. what Oldsock used. I'd just use BeerSmith's since you now have it entered in there.

Oldsock said:

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).
>>>>>>>>>>>>>>>>>>>>>>>>>

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I couldn't figure out an easy way to figure the %'s by weight.
Say if I want 5 gallons of 1.060 beer with 80% 2 row, 10% c40L, and 10%Munich. And I get 70% efficiency, how would one figure it by weight?

dzlater said:

I couldn't figure out an easy way to figure the %'s by weight.
Say if I want 5 gallons of 1.060 beer with 80% 2 row, 10% c40L, and 10%Munich. And I get 70% efficiency, how would one figure it by weight?

Click to expand...

My quick way to estimate is to multiply the gravity of the beer (60) by the volume (5) and divide by your system efficiency (.7) to get the total points needed (428).

Divide the total points (428) by the approximate points per pound the grains give (base malts are around 38, most specialty malts are a bit lower) 36 is usually a good guess. In this case that means you need 12 lbs of grain.

Then just apply the percentages you want by multiplying the total pounds of grain by the percentages of each. In this case that gets you 1.2 lbs for the Munich and C40, and 9.6 lbs of 2 row.

Oldsock said:

My quick way to estimate is to multiply the gravity of the beer (60) by the volume (5) and divide by your system efficiency (.7) to get the total points needed (428).

Divide the total points (428) by the approximate points per pound the grains give (base malts are around 38, most specialty malts are a bit lower) 36 is usually a good guess. In this case that means you need 12 lbs of grain.

Then just apply the percentages you want by multiplying the total pounds of grain by the percentages of each. In this case that gets you 1.2 lbs for the Munich and C40, and 9.6 lbs of 2 row.

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Cool thanks