Calculating sparge water

Strike is easy, xyz lbs. x 1.33, but what's the general number for finding sparge volume?

.5 G per lb? Maybe. The best way is heat that much and sparge until your runoff is 1.010 SG.

One of the many things I like about decoction mashes is you sparge with everything that is left until you hit your preboil volume. If you sparge until you get to 1.010 you might be boiling for hours depending on how efficient your MLT is.

ChemE said:

One of the many things I like about decoction mashes is you sparge with everything that is left until you hit your preboil volume. If you sparge until you get to 1.010 you might be boiling for hours depending on how efficient your MLT is.

Click to expand...

My solution to having to boil down a large volume was to get more powerful burner. I can get 2 gallons of boil off an hour now not even trying.

And if you're doing really big beers where you could potentially have to boil down a huge volume, then you could get good efficiency by using a multiple batch sparge method.

Wow, that's a crazy evaporation rate. How many BTU's is your burner? Does it eat propane canisters like Pez?

ChemE said:

Wow, that's a crazy evaporation rate. How many BTU's is your burner? Does it eat propane canisters like Pez?

Click to expand...

Claims to be 185k BTUs. Since getting it the sides and bottom of my pot have some new color to them. The old burner my pot didn't even look like it was used.

I really just love the control of the flame though. It has a fixed psi regulator and what seems to be a needle valve. Really precise control. It's the Bayou Classic SP-10.

As far as propane usage, I think I'm 2 AG batches into this tank and it seems to have a good bit left. At least one more batch if not two.

I never really put much thought into calculating sparge volume. Software just makes it too easy. If I'm starting out with 7 gallons pre-boil and I only get two gallons from my first runnings, then I know I need to collect 5 more. The grain isn't going to absorb more water after the first time around, so using Bobby M's double batch sparge I use 2 equal infusions of 2.5 gallons. Once you have your brewing efficiency set, it works just about every time.

I guess if you don't have software, you'd have to measure your gravity to know when to stop sparging. The only problem I see with this is that you might get stop when your gravity reaches 1.010, but if your efficiency was better or worse you would end up with more or less wort for the boil.

I probably didn't help you in the least bit, but I'm curious to see if there is a way to figure this all out with software and still get your desired boil volume.

I'll second what McKBrew said, and if your lazy like me, you don't want to sit around waiting for wort to boil down just so you can start your 60 minute hop additions. I'd rather take the hit on efficiency. The key to my laziness is to figure out what your preboil volume is going to be so that you boil for 60 minutes and you end up with 5.25 gallons (or whatever your target is). For me it's about 6.5 gallons. Then work backwards from there based on what McKBrew said.