Mash Out, Sparge Water temp control

So I'm building my brew stand, three level, and I have an HLT on top with a burner. It's a bit higher than I would like but will do I guess. My proposal is to fill it with the total volume plus some of the water required and then using my sight glass, let water flow into the mash tun. My question is how can I calculate how much ice to add to my 200 degree water to drop it to 168 for sparging?

IMHO you don't want to drop the water to 168. You want the grain to be at 168...which usually means that if your talking about a 10 gal batch you want to add 200 water to get the grain bed up to 168...or for a 5 gal batch probably something like 185 sparge water.

I'm assuming the OP wants to fly sparge and in that case, it's pretty common to use a minimal amount of boiling water to get to 168 and then use 168F sparge water the rest of the way.

Now, I wouldn't heat the entire mashout + sparge water volume up to 200 or boiling or whatever you like. Think about it, you're using energy to reach that temp and then using extra energy to make the ice to drop the temp.

Two ways to go: Heat the mashout water in a separate vessel like your boil kettle or figure out how much of the sparge volume should be made up of fresh tap water added after the mashout is removed.

The latter is tricky but not impossible. I'm sure you can build a spreadsheet to figure it out based on the concept of temperature averaging (e.g. 1 gallon of 100F added to 1 gallon of 200F will equilibrate to 2 gallons @ 150F)

Practical example. Let's say you want 2 gallons for mashout and 5 gallons for sparge.

If you heat 5.5 gallons to boiling (212F for me), remove 2 gallons for mashout. Add 1.5 gallons of tap at room temp (70F) to the 3.5 gallons remaining in the HLT and the entire combined 5 gallons should now be at 169F and ready to go.

If iuse brewsmith it tells me typically to
Mash X gal at Y degrees to achieve 150 mash for Z min
Mash out X1 gal at Y1 (200 deg) for Z1 (2) MIN
Sparge with X2 gal at Y2 degree. I fly sparge that.

So if I heat water to 200 for mash out and use 2 gal, I have X2 gal left in HLT and only have a few minutes to get it down to 168 (Y2) to fly sparge. I was going to add ice to drop this temp and wondered if there was a calculation readily available. My fizix books are long gone

Bobby_M said:

I'm assuming the OP wants to fly sparge and in that case, it's pretty common to use a minimal amount of boiling water to get to 168 and then use 168F sparge water the rest of the way.

Now, I wouldn't heat the entire mashout + sparge water volume up to 200 or boiling or whatever you like. Think about it, you're using energy to reach that temp and then using extra energy to make the ice to drop the temp.

Two ways to go: Heat the mashout water in a separate vessel like your boil kettle or figure out how much of the sparge volume should be made up of fresh tap water added after the mashout is removed.

The latter is tricky but not impossible. I'm sure you can build a spreadsheet to figure it out based on the concept of temperature averaging (e.g. 1 gallon of 100F added to 1 gallon of 200F will equilibrate to 2 gallons @ 150F)

Click to expand...

Great idea on using the other burner to heat my mash out. Had not thought of that. Haven't used two burners yet! Problem solved. Thanks Bobby...will be all set now and better when my sightglass arrives