# Help needed with an equation ### Help Support Homebrew Talk: #### hopeye

##### New Member
Hi,

I'm currently gearing up to go AG and am expanding my own brewing software that I have written in VBA with MS-Access. I have discovered that I need an equation/algorithm to calculate the required temperature (either farenheit or celsuis) of a set volume of hot liquor (say 20 litres) to a mash that is currently at 60 degrees celsuis and contains 30 litres HL and 24KG of grain. I have Palmers equations to calculate the volume of water to add of a
given temperature, but, what I am looking for is an algorithm to calculate what temperature a set volume of water is required to be to reach a desired target temperature.

I have Palmer's equation to calculate the amount of hot liquor given the temperature of it, which is as follows:

Initial Infusion Temp equation
Strike Water Temp TW = (0.2/r)(T2 - T1) + T2

Mash Infusion Temp equation
WA = (T2 - T1)(.2G + Wm)/(Tw - T2)

where

r = The ratio of water to grain
WA = The amount of water to add
Wm = The total amount of water in the mash
T1 = Teh initial temp of the mash
T2 = The target temp of the mash
Tw = The actual temp of the infusion water (Hot Liquor)
G = The amount of grain in the mash

What I need is an equation/algorithm to calculate the temperature what the temperature of a set volume of Hot Liquor

needs to be to reach a desired rest temperature.