Technique Academy
Fat-Washing Spirits at Home
Fat-washing infuses spirits with fat-soluble flavor compounds from butter, bacon, coconut oil, and other fats, then removes the solidified fat to leave behind a crystal-clear spirit with a rich, savory, or nutty dimension that no other technique can achieve.
Fat-Washing is one of the most transformative modern bartending techniques. It allows you to add the flavor of butter, bacon, toasted sesame, coconut, or nut oils to a spirit without making the drink greasy, cloudy, or unpleasant. The result is a spirit with a rounded, savory, or nutty complexity that feels unlike any commercial bottling.
The Science
Fats are excellent solvents for certain flavor compounds — specifically, fat-soluble aromatic molecules. When you mix a fat with a spirit, those molecules migrate from the fat into the ethanol. When you then freeze the mixture, the fat solidifies (ethanol has a much lower freezing point than fat) and can be physically removed. The flavor compounds remain in the spirit because they are more soluble in ethanol than in the now-solid fat.
What makes fat-washed spirits unique is that they also pick up a very small amount of the fat's mouthfeel enhancement — not greasiness, but a slight roundness and weight on the palate. This is because some fat molecules are too large to migrate but leave a trace lipid coating on the ethanol molecules.
Common Applications
- Brown butter bourbon: Used in the Fat-Washed Old Fashioned. The nuttiness of browned butter pairs naturally with the caramel and vanilla notes of bourbon.
- Bacon-washed bourbon or rye: Classic combination for savory cocktails. The smokiness and salt complement whiskey's natural grain notes.
- Toasted sesame oil-washed gin: Produces an earthy, aromatic gin suited for East Asian-inspired cocktails.
- Coconut oil-washed rum: Enhances the tropical character of rum without adding coconut sweetness.
Equipment
- A large glass jar or lidded container
- A fine-mesh strainer or cheesecloth
- A freezer
- A skimmer or large spoon
- The spirit bottle (and a spare container for storage)
Step-by-Step Technique
Step 1: Prepare the Fat
For brown butter: melt unsalted butter in a saucepan over medium heat, stirring constantly, until the milk solids turn golden and the butter smells nutty (about 5 minutes). Remove from heat and allow to cool to room temperature — do not use hot fat on cold spirits as it can cause unusual flavor development.
For bacon fat: cook bacon until crispy. Strain the rendered fat through a fine-mesh strainer to remove solids. Let it cool to room temperature before using.
Step 2: Combine Fat and Spirit
Pour the spirit into a glass jar. Add the fat. The ratio is approximately 1–2 tablespoons of fat per 500 ml of spirit. Less fat produces a subtler result; more fat produces a stronger flavor and increases the risk of residual off-notes if the freezing step is not thorough.
Seal the jar and shake well. Let the mixture sit at room temperature for 4–6 hours, shaking or stirring once per hour. For a more intense flavor, extend to 24 hours. Keep at room temperature — do not refrigerate during the infusion phase as this begins solidifying the fat prematurely.
Step 3: Freeze and Separate
Transfer the jar to the freezer. Leave for a minimum of 2 hours, or until the fat layer on the surface is completely solid and firm. For high-fat mixtures, overnight freezing is more reliable.
Remove from the freezer. The fat will have solidified into a firm disk or cap on the surface of the spirit. Break the fat cap with a spoon and lift it out. Some residual fat traces will remain in the liquid — these will be removed in the next step.
Step 4: Fine Strain
Pour the spirit through a Fine Mesh Strainer lined with a layer of cheesecloth or a coffee filter. This removes all remaining fat particles, micro-droplets, and any solids. The finished spirit should be completely clear.
Repeat the fine-straining step if any cloudiness remains. Cloudiness at room temperature indicates remaining fat particles.
Step 5: Bottle and Store
Transfer the fat-washed spirit to a clean, sealed bottle. Label it with the fat type and date. Store at room temperature or refrigerate. Fat-washed spirits are stable at room temperature for several weeks. Refrigeration may cause the spirit to cloud slightly (the residual fat traces semi-solidify in the cold) but this clears at room temperature.
Safety Considerations
- Never use rancid or off-smelling fat — it will ruin the spirit.
- Ensure the fat is at room temperature before combining with spirits. Adding very hot fat to alcohol can release vapors.
- Animal fats (bacon, lard, butter) have a shelf life. A fat-washed spirit using bacon fat should be consumed within 2–3 weeks to avoid any off-flavor development from the animal fat components.
- Discard the fat solids after use. Do not reuse fat that has been infused into alcohol.
Troubleshooting
- Spirit is still cloudy after straining: The fat has not fully solidified or the strainer is not fine enough. Freeze again and use a coffee filter.
- Flavor is too faint: Increase the ratio of fat, or extend the room-temperature infusion period.
- Off-flavors: The fat was low quality, rancid, or the infusion ran too long. Start over with fresh fat and a shorter infusion.
Fat-Washing rewards experimentation. Once you understand the basic principle, you can apply it to almost any fat-soluble flavor: truffle oil, sesame, beef tallow, or nut butters.