Page 38 - Craft of Whiskey Distilling

25 | AmErICAn DIstIllInG InstItutE
Below are the inputs used to calculate the requirements of the mash: Grist Temperature — 75 degrees F. (24 C)
Ingredients 690# — 2 Row Great Western Malt (Canada) Targeted Mash Temperature — 155 deg. F (62.8 C)
Dough In Water Volume — 227.7 gallons (861.9 l, 7.34 uS bbl.)
Mash Tun Thermal Mass — 0 (assumes no heat loss to the mash tun) Heat Loss Due to Piping/Pumping — 12 deg. F (-11.11 C)
Heat Loss to Grist — .017 deg. F per pound of grist at 75 deg. F. (-17.76 C per .45 kg grist)
Water Volume Lost to Grist — 690 # Grist X .12 Water Loss per # = 82.8 gallons (313.4 l)
Therefore...
Grist Heat Loss — .017 X 690 pounds grist @ 75 deg. F = 11.7 deg. F (-11.27 C)
Piping Plumbing Heat Loss — = 12.0 deg. F (-11.10 C) Total Heat Loss — = 23.7 deg. F ( -4.61 C)
Targeted Mash Temperature — = 145.0 deg. F ( 62.80 C) + Total Heat Loss = 23.7 deg. F (-5.4 C)
Dough In Hot Liquor Temperature — = 168.7 deg. F (75.94 C)
So, for this example, you would set the hot liquor temperature to dough in at 169 deg.
F (76.1 C)
Sparge Water — Beyond the 228 gallons that needs to go into the mash, you will also need to know how much sparge water you will need to make up for the water that was absorbed by the grain (82.8 gallons) and that to reach a fermentable volume of 250 gallons.
Therefore...
Dough In Water Volume — 227.7 gallons (861.9 l, 7.34 uS bbl.) • Water Loss to Grain 82.8 gallons (313.4 l) = Mash Tun Wort
Volume: 144.9 gallons (548.49 l, 4.67 uS bbl.)
Fermentable Volume Targeted: 250.0 gallons
• Mash Tun Wort Volume: 144.9 gallons = Makeup Sparge
Water Required: 105.1 gallons (397.83 l, 3.39 uS bbl.)
Now, I wish this calculation was that easy, but it is not. This does not take into account how much foundation water you put in the mash tun prior to doughing in. It also does not take into account how much loss to deadspace that is present in your vessel nor the pip- ing leading to the hydrator and sparge mechanism. These variables are different for every