This is the fat wash most bartenders meet first. Don Lee built the Benton's Old Fashioned on it at PDT in 2007 — Four Roses bourbon washed with fat rendered from Allan Benton's Tennessee smokehouse bacon, then served with maple syrup and Angostura over a large cube. Eben Freeman had popularized fat-washing at Tailor two years earlier; Lee put it in a drink people already knew how to order. The technique is standard now. The bourbon is still the reference version.
What the Fat Carries
Bacon tastes of two things at once: the pork itself, and the hickory smoke it was cured in. Both register through compounds that dissolve far better in fat than in water, which is why dropping a strip of bacon into a glass of bourbon does almost nothing. The fat is where those compounds already live. Stir it into the spirit and the alcohol pulls a share of them across, then the freeze takes the fat back out and leaves the flavour behind.
A trace of the fat itself stays in solution. That is the part you feel rather than taste, a rounder body and a finish that hangs on longer than 80-proof bourbon usually does. It is also the part that sets the shelf life, since fat is the only thing in the bottle capable of going off.
Why Bacon Is an Easy Fat to Work With
Rendered bacon fat is liquid on the stove and solid at room temperature, and that gap does most of the work. Warm, it pours and disperses through the bourbon. Cold, it sets into a firm cap you can lift off in one piece instead of chasing an oil slick around a jar. Freeze the whole thing and the separation is total: the fat goes hard, the bourbon stays liquid because ethanol will not freeze in a domestic freezer, and the two come apart cleanly.
Filter cold, and keep it cold while you filter. A jar left on the counter halfway through straining will warm past the point where the fat holds its shape, and the last of it runs straight through the cheesecloth into the finished bottle. If the bourbon looks cloudy after a night in the fridge, that is what happened; run it through a fresh coffee filter cold and it clears.
Rendering the Fat
Half a pound of bacon gives up roughly the ounce and a half a 750 ml bottle needs, though it varies with the cut and how hard the bacon was smoked. Cook it slowly in a dry pan over low heat so the fat renders out before the meat browns; you want clear liquid fat, not fond. Pour it through a fine strainer to catch the solids, which scorch and turn the wash bitter if they ride along. Benton's is the bacon Lee used, and it is cured dry and smoked hard, which is why the drink reads as smoky rather than merely savoury. Any dry-cured smokehouse bacon works. Bacon cured in a wet brine renders more water and less flavour.
The Bourbon Underneath
Four Roses yellow label at 80 proof is the reference, and the logic holds for anything similar — Buffalo Trace, Old Forester 86, Wild Turkey 81. What you want is a bourbon that stays out of the way. Heavily charred or extra-aged bottlings bring their own smoke and tannin, and stacking those on hickory puts two kinds of smoke in a glass that already contains maple syrup. Spend the money on the bacon.
Keeping It
Bottle it and keep it refrigerated. Filtered properly it holds for about two months, and the limit is the residual fat rather than the alcohol — trace lipids oxidize eventually, and a rancid wash announces itself on the nose long before it reaches the palate. Make it in bottle quantities when you are going to drink it, not as a standing item on the back bar.