The component behind Benton’s Old Fashioned and the Brown Butter Old Fashioned, and one of the few genuinely modern cocktail techniques that is worth the trouble at home.
What it does, and why it is not just an infusion. Many aroma compounds are fat-soluble rather than water-soluble, so they will not come out into a spirit on their own. Give them a fat to ride in, let the two sit together, and the flavour crosses over. Then — and this is the whole trick — freeze the mixture solid and lift the fat off, because at freezer temperature the fat sets hard while the alcohol stays liquid.
What you are left with is bourbon that tastes of bacon or brown butter or toasted nuts, and carries a noticeably heavier mouthfeel from the trace fat that stays behind. That weight is half the point; it is what makes a fat-washed drink feel richer than its ingredients suggest.
The technique came into bars from the kitchen — Don Lee learned it from the chefs at wd~50 and used it for Benton’s Old Fashioned at PDT in 2007, which is where most bartenders first met it.
Ingredients
- Bacon version
- 2 oz rendered bacon fat, warm and liquid (see Bacon Grease)
- 1 1/2 cups bourbon
- Brown butter version
- 3 oz unsalted butter, browned (see Brown Butter (Beurre Noisette))
- 1 1/2 cups bourbon
- Also good
Toasted pecan or walnut oil, 1 oz
- Coconut oil, 2 oz — melts clean, very easy to remove
- Duck fat, 2 oz
Directions
- Render or brown the fat and let it cool until it is warm rather than hot — pouring genuinely hot fat into spirit is both a fire risk and a good way to boil off alcohol.
- Pour the fat into the bourbon in a wide-mouthed jar. Wide-mouthed matters — you have to get a solid disc out of it later.
- Stir, seal, and leave at room temperature for 1 to 4 hours. Give it a shake whenever you pass. Longer is not better past about four hours; you are extracting flavour, not making stock.
- Into the freezer for at least 8 hours, ideally overnight. The fat sets into a solid cap on top; the bourbon does not freeze.
- Lift the fat disc off in one piece. If it broke up, fish out what you can.
- Strain the bourbon through a coffee filter — not just a fine mesh. This is the step that decides whether the drink is silky or greasy, and it is slow. Let it drip; do not push it.
- Bottle, label with the date, and refrigerate.
Notes
Ratios are forgiving. Roughly 1–2 oz of fat per cup of spirit is the working range. More fat is more flavour and more work at the filter.
⚠ Refrigerate it and use it within about a month. However well you filter, trace fat remains, and trace fat eventually goes rancid. Alcohol slows that down; it does not stop it. If it smells like old cooking oil, it is done — throw it out.
⚠ Never pour hot fat into spirit near an open flame, and do not do this step next to the torch you are using for the brûléed orange.
Cloudiness after filtering means fat is still suspended. Put it back in the freezer for a few hours and filter again — it will clear.
Salt carries over. Bacon fat brings salt with it, which is generally welcome and is part of why the Benton’s works. If you are washing with something salted and do not want that, use unsalted.
What to wash with what: bacon and duck fat go to maple and Angostura; brown butter goes to lemon and sugar in a sour; toasted nut oils go to a spirit-forward build with demerara. Coconut oil is the easiest to remove and the mildest in flavour, which makes it the best one to practise on.