All-Grain Recipe Formulation Question

[Ace_Club]

So, if I'm doing an all-grain 10 gallon batch, but am shooting for 12-13 gallons into the BK, which volume should I formulate my recipes to? Should I formulate using the 10 gallon number assuming that the 12-13 gallons into the BK will be on the low side gravity-wise but will concentrate during the boil, or do I formulate based on the volume I expect to get into the BK (i.e., the 12-13 gallons)???

 

[TheMan]

I'm not sure I understand your question. But you formulate just like you would for a 5 gallon batch. Also, I formulate based on final volume desired, not what I want preboil

To add to that, most people aim to acheive a post boil volume of just a bit more than what is going into the fermenter, to account for trub. I base my batches on a 5.5 gallon post boil amount. A 10 gallon batch I base on getting 11 gallons post boil.

 

[dzlater]

Either way. The way it was explained to me is, to use total gravity points and then divide that by percentages also taking into account efficiancy and points per lb per gallon of the different grains.
12 gallons preboil with a gravity of 1.050=600 gravity points (50x12)
if you calc the post boil gravity @ 10 gallons you get 1.060
vol1xgravity1=vol2xgravity2
(12x50)/10=60
60x10=600 post boil gravity units
so you would need to design the recipe using 600 gravity units as the target

 

[coypoo]

Just focus on your post-boil volume. Everyone has different boil off rates and therefore the recipe can be the same, the post-boil can be the same, but the pre-boil volume will vary a lot. For me, I almost boil off 2 gals/hour, which is much different than other people. I shoot for 7 gals pre-boil, other shoot for 6, etc. As long as you know your efficiency you can tweak a recipe in a recipe calculator to get your desired OG.