Minturn Whisky Co.
How much water do I need to add to proof my whisky?
Adding a little water to cask strength whisky opens it up. Here is exactly how much to add when you’re playing around with proofing at home.
Add this much water
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The arithmetic
water = volume × (starting proof ÷ target proof) − volume
Proof is simply twice the alcohol by volume, so 102 proof is 51% ABV. The alcohol in your glass does not change when you add water. Only the total volume does, which is why the sum works the way it does: you are figuring out how big the finished pour has to be, then topping up the difference.
The hotter the whisky, the more water it takes. Something at 102 proof needs about a quarter as much water as whisky to reach 80. Something at 124 proof needs about half.
Why water helps at all
Three things happen at once. Ethanol vapour sets off the trigeminal nerve, which senses irritation rather than smell, so a cask strength pour is literally harder to smell past. Most of what makes whisky interesting is better dissolved in alcohol than in water, so weakening the solvent pushes those compounds up into the air where your nose can reach them. And the smoky phenols in particular, guaiacol most of all, sit near the surface of the liquid at lower strengths and get pulled down into the bulk at higher ones.
Take it slow, once you pass a certain point the whisky goes thin and lifeless. Where that point sits differs for every bottle and every nose, which is why adding water a few drops at a time and tasting as you go beats any number a calculator can give you.
How low can you go?
Below 80 proof a spirit can no longer be called whisky in the United States. For a glass on your own table that means nothing at all. For anything going into a bottle with a label on it, 80 is the bottom.
Blended and bottled in Minturn, Colorado, at 7,861 feet.
minturnwhisky.com
Minturn Whisky Co.
Make a proofing chart for your own whisky
Put in what you have and how much you pour, and you get the whole table at once. Print it and keep it wherever you keep the bottles, so you never have to work it out again.
Three bottles are the most anyone needs at once. Clear a field you are not using and that column drops away. The figures shown are our own three, if you would like something to try it on.
Proofing chart
Water to add
Se
y
Opens a clean one-page version.
How to use it
Measure your whisky first, then find the proof you are aiming for down the left and read across. The number in the cell is how much water to add to the pour size you set. Add it slowly and taste as you go, because the chart tells you where you will land, not where you will like it.
If you have no cylinder, a teaspoon is just under 5 ml and a tablespoon is just under 15 ml. Close enough for a glass, though worth being more careful than that if you are working with something you cannot replace.
Blended and bottled in Minturn, Colorado, at 7,861 feet.
minturnwhisky.com