Strike Water Temperature Calculator

Strike Water Temperature Formula

The strike water temperature calculator above uses the formula detailed by Dan Carrey during a presentation at the 1988 American Homebrewers Association conference.

In it’s simplest form, this is the formula he presented:

Aa + Bb = Cc

The variables in the formula are probably best described by Mike Miller:

The capital letters A, B, and C stand for the specific heats of grain, water, and the mash, respectively, and the lower case letters stand for temperatures of the same variables.

What the formula says is that the product of the temperature and specific heat of a mixture will be equal to the sum of the products of the specific heat and temperature of the two substances that make up the mixture – in this case, water and grist.

A = Heat of grain
a = Temperature of grain °F
B = Heat of water
b = Temperature of Water °F
C = Heat of Mash
c = Target Temperature of Mash °F

For the life of me I can’t imagine why Mr. Casey decided to use such confusing terminology (heat vs temp), but I promise the formula starts to make much more sense once you apply real world values to the formula.

So let’s go through a quick example using the following values from our calculator above.

So let’s pretend for a moment that we don’t know our resulting Strike Water Temperature and we are trying to solve for the example batch information above.

Let’s start by entering in our known values:

A = Grain Weight * 0.05
a = Temperature of grain °F
B = Strike Water Volume (gallons)
b = Strike Water Temperature °F
C = A + B
c = Target Temperature of Mash °F

A = 14 lbs * 0.05
a = 70°F
B = 10 gallons
b = Strike Water Temperature °F
C = A + B
c = 153°F  (156°F adjusted for thermal loss)
**Descriptions adjusted for clarity

Now we can begin to solve for strike water temperature (b).Aa = .70 * 70 = 49
Cc = (.70+10) * 156 = 1,669.2
Bb = 10*b

Now to apply our original formula…Aa + Bb = Cc
49 + 10b = 1,669.2

And adjust to solve for b.10b = 1,637.1 – 49 = 1,620.2

b = 1,620.2 / 10 = 162.02 °F

Alternate Strike Water Temp Formula

Another popular formula for calculating strike water temperature is John Palmers Initial Infusion Temperature formula.W = (.2/R)(T2-T1)+T2
Where:
W = Strike water temperature °F
R = Water to grist ratio in quarts/lb (i.e. 1.25 or 1.5)
T1 = Temp. of your dry grain °F
T2 = Desired mash temp °F

Using the same information from our above calculator, let’s calculate our strike temperature using John Palmers formula.

W = Strike water temperature °F (?)
R = Water to grist ratio in quarts/lb ( 40 quarts/14 lbs = 2.857)
T1 = Temp. of your dry grain °F (70)
T2 = Desired mash temp °F (156 – adjusted for thermal loss)

W = (.2/R)(T2-T1)+T2

Now to plugin in our values from above into our formula:

W = (.2/2.857)(156-70)+156
W = (.07)(86)+156

W = 162.02 °F