Page 58 - Craft of Whiskey Distilling

AmErICAn DIstIllInG InstItutE | 47
AgINg THE 53-gALLONS OF MALT wHISkEy pRODuCED IN CHApTER 4
As mentioned above, American straight whiskies are aged in new charred oak bar- rels, while more delicate flavored spirits like the malt whiskey produced in the previous chapters are aged in used-once barrels, such as used bourbon barrels. So, to age our malt whiskey, an empty bourbon barrel is required.
pREpARINg THE bARREL
If the barrel was recently emptied and there are no visible signs of major leakage any- where on the barrel, then it’s ready for filling. However, if the barrel has been empty for awhile, and the wood has dried out, the barrel will leak between its staves. So, it will have to be rehydrated to swell out the wood to close all the leaks. This is done by placing the barrel near a drain and filling it full of water with a hose. The barrel will leak so adjust the water flow so that the barrel stays full. It typically takes 24 to 48 hours for the barrel to seal itself, and the rate of filling can be turned down every few hours. If after rehydrating the barrel for 48 hours, there’s still a leak between two staves, find where along the staves the water is leaking, and take about a 1/2 inch wood chisel and hammer it into the oak about a o inch deep, and about a 1/2 inch from the seam between the staves. Do this on both staves on each side of the leak. Then take two small wedges of cedar and hammer one into each slit made with the chisel. This will tighten the seam between the two staves and seal the leak. Do this for all leaks between the staves. Once the barrel is sealed, it should be kept full of water until the whiskey is ready to go in.
DILuTINg THE wHISkEy
As explained above, 55 to 65% abv is the optimum range of percent alcohol for barrel- aging whiskey, so for our malt whiskey we’re going to dilute it to 60% abv.
In a vat capable of containing at least 53 gallons, prepare a 53-gallon quantity of 60% malt whiskey by diluting the hearts from the spirit run in Chapter 4 to 60% abv with pure water (i.e. distilled or RO water).
The dilution calculation should be done using the following formula: Quantity of hearts = 53 X 0.6 / percent alcohol of hearts
Quantity of pure water = 53 - Quantity of hearts
example: Say, the hearts were 70% abv
Quantity of hearts = 53 X 0.6 / 0.7 = 45.43 gallons of heart
Quantity of pure water = 53 - 45.43 gallons = 7.57 gallons of pure water
Of course, you may chose to dilute the entire quantity of hearts to 60% abv, and to do so, you would use the following formula to calculate the amount of pure water to add: