Calculating Strike Water Temperature

[Carter1932]

This weekend I am participating in a brew-in being sponsored by a local microbrewery, Bluegrass Brewery Co. (BBC).

I am told that we'll be supplied tap water of approx. 170 deg. F. My software tells me that I my initial protein rest infusion will need approx. 132 deg. F. water to hit a mash of 122 deg. F, and later the saach rest requires 153 deg. F.

Obviously I will have to cool down the 170 deg. to the 132 deg.F, so my question is can someone provide a formula for calculating water temps when mixing various volumes of H2O at different temperatures?

Thanks.

 

[binkman]

Just average the temperatures (as weighted by the volume of water). So if you've got 1 gallon at 170 and 1 at 130, you'll end up at 150. But if its 2 gallons at 170 and 1 at 130 you'll finish 2/3 of the way towards 170, so 2/3 of 40 is about 27, so 157. Etc.

I.e.
(2 x 170) + (1 x 130) = 470

Divide 470 by the total volume of water (3 gallons) = 157 (actually 156 and 2/3 F).

 

[Carter1932]

Cool.. thanks!

 

[ayoungrad]

If you hate math:

http://www.rackers.org/calcs.shtml