Amount of spare water needed...

[magnoliabrew]

I am attempting my first all grain brew tomorrow. I have 10 lbs 6 oz of grain for an amber ale recipe. My calculations show my mash water to be 2.91 gallons. This is to be a 5 gallon post boil batch. If I also calculate my gear to boil off approx 2 gallons over an hour, is it correct that I am sparging with almost 4 gallons to meet pre-boil level (7 gal)? Extracts with specialty grains never required this step. Brewing on a RIMS system, so not batch sparging.

 

[wilserbrewer]

You will lose about a gallon to grain absorption, and if you anticipate 2 gallons boil off, your total water required will be approx 5 + 1 + 2 = 8 total gallons required.

Some also figure loss to trub yeast cake at 10% batch size, ymmv

Ps you don't really need any spare water lol cheers

Pss 2 gallons boil off seems a bit high for a typical 5 gal batch...assuming large kettle and heat source idk

 

[magnoliabrew]

I meant sparge water...auto correct.

 

[magnoliabrew]

I also think a 2 gallon boil off is high and I think that number popped up on beer smith for a 10 gallon batch. In any case, sparging is new to me and it just seems like a lot of water to do that. Thanks for the reply!