Grain adjustment for 5 gallon batches

[bigchilla77]

Hey guys
I'm an extract brewer who just switched to 5 gallon batches with a turkey fryer, I think I read on here that the grain for steeping needs to be adjusted from say a 2 or 3 gallon batch to a 5 gallon batch. I was wondering if there is some kind of equation or rule on how to make those adjustments. Thanks.

 

[cweston]

When you say "2 or 3 gallon batch," do you mean a 5 gallon batch where you boil 2 or 3 gallons and then top off with water to equal 5 gallons in the fermenter?

So you're changing you boil volume, not your batch size, right?

(If not, then ignore the rest)

It's not the specialty grains that need to be adjusted when you go to a full boil process--it's the bittering hops.

Extraction of bittering compounds from the hops is more efficient at lower gravities. Since you're putting the same amount of sugars in a larger volume of water, the boil gravity is lower.

Getting the right amounts can be tricky--that's where commercial or free software can really come in handy.

 

[bigchilla77]

Yeah sorry i meant boil size not batch size. So it is the hops that need adjusting not the grains. Where can I get a copy of the software? Thanks.

 

[cweston]

The beer recipator is a good free site. Enter in your extract, grains, batch size, , hops amounts, and the boil size FOR THE ORIGINAL RECIPE. Note the IBUs. You should do this even if you know the target IBUs of the original recipe.*

Then change the boil size to 6 gallons or whatever amount you plan to start the boil with, and fiddle with the bittering hops to match the IBUs of the original recipe. You don't have to adjust flavor and aroma hops--they contribute a minimum amount of bitterness.

*The reason for this is that there are different ways of calculating IBUs--if you want comparable results, you need to make sure the IBUs are calculated based on the same algorithm.