Mash/Sparge H2O Amounts

Brewing Processes
1

hey all - i’m a fairly new AG brewer and i’m having some problems trying to calculate how much water i should be using in my mash and during my sparge process … would really appreciate your input as to what i’m doing wrong.

for my next 5 gallon brew, i have a total of 20 lbs of grain (plus 1 lb of candi sugar).  i also have 11 quarts of dead space in my mash tun.  how much water should i be using for my mash?

also, with that same brew, how much water should i sparge with?

thanks very much in advance!

2

Batch sparging or fly sparging?

3

fly sparging

i calculated that i’ll need the following:

MASH - 7.5 Gallons (plus 11 Q dead space) = 10.25 Gallons of water

SPARGE - ??  I was told 2Q water per 1 pound grain … that equals 10 gallons, which seems like way too much.

am i anywhere close?

4

Your large amount of dead space is really going to shoot you in the foot here. If you don’t want to mash any thicker than, say, 1.0 qt/lb in order to be able to work with the mash, you’ll infuse 201 + 11 = 31 qt = 7.8 gal. And you’ll be able to recover 7.8 - 200.12 - 2.8 = 2.6 gal. You could then sparge with 3.9 gal if your pre-boil target is 6.5 gal, for example.

Sparging until the runnings hit a target gravity (3°P or whatever) probably won’t be an option due to the deadspace, unless you’re willing to start with a very large pre-boil volume - 12.6 gal if you used 2 qt/lb for sparging.

5

‘large’?  That’s more like gigantic, or enormous, or even ginormous :slight_smile:

6

yea, i agree … which i’m slowly realizing may be the source of my watered down brews … i’ve had to call my last 3 batches “light” beers …

looking into adjusting the false bottom i picked up for my MegaPot from Northern Brewer … dropping it down at least an inch

hopefully that does the trick …

7

It really depends on what you mean by dead space.  If by dead space, you mean space under the false bottom, then it is not a big deal.  If by dead space you mean volume that is not drained from the mash tun, then 11 quarts is a big deal.  Dropping your false bottom won’t help with that though, which is why I think you mean the first version.  If it is a problem of not draining, adjust the pickup tube so that is reduced.  If it is extra water under the false bottom, drop the false bottom if it is easy, if not no big deal.  It’s a lot, but it’s not the worst thing in the world.

8

I have the screen tube which I got from the LHBS.  This effectively makes the deadspace in my mash tun less than two cups of coffee.  Virtually everything drains.  No issues with clogging either.

What advantage does the false bottom offer that I’m missing?

9

False bottom can be an advantage if you fly sparge.  The false bottom having holes across the entire surface is thought to lessen channeling.  For batch spargers, there’s no real advantage.

10

Good answer.  I will keep that in mind when I eventually switch to fly sparging.  I’d need a different setup than I have now tho.

OP: Couldn’t you devise something with less dead space?

11

I don’t suppose that expansion foam insulation stuff is food-grade…  Maybe a couple gallons of marbles?