Originally Posted by Wingfan13
Here is how I am looking at it and please let me know if I am off.
I have a recipe that uses 13.4 pounds of grain. If I cut that in half it is 6.7 pounds of grain.
6.7 pounds of grain
x 1.25 = 8.375 quarts which is 2.09 gallons
+ 1 gallon for boil off (looked this up as an good starting point)
+ .1 gallon per pound of grain (also looked this up as a starting point) = .67 gallons
I would need 3.76 gallons to start ? Does this look right ?
Thanks for the help !
The .1 gallon/lb grain is going to be lost from your strike volume, so if you strike with 2.09 gallons you will lose 0.67 gallons of volume (=1.42 gallons).
Now if you want to do a sparge here, you can use whatever volume you want that will raise the 1.42 gallons to the total volume you want pre-boil.
So say you boil off 1 gallon/hour in your kettle, then you can sparge with 2.08 gallons to get 3.50 gallons pre-boil total volume, and then start your 60min boil to get it down to 2.5 gallons post-boil.
Or you can be lazy like me and just make a calibrated stick with notches for gallon measurements specific to your kettle. Then just estimate the amount of water and boil it all down till you get to your desired pre-boil volume. Some say extended boils cause carmelization, yada yada, but it's worth it to me.