If you have ever tasted a bourbon that smells faintly of bacon, you have probably had a fat-washed spirit. The technique is one of the most useful and least understood things in modern bartending. It looks like magic and it is actually just basic chemistry.
What fat-washing does
Fat carries flavour that water and alcohol cannot. Some of the most distinctive notes in any food, the savoury depth of bacon, the toast of brown butter, the creaminess of coconut, the perfume of olive oil, sit inside fat molecules. Pour bacon directly into bourbon and you get a greasy bourbon. Wash bourbon with bacon fat, freeze it, strain off the solidified fat, and you get a bourbon that smells of bacon with no fat in the glass.
The mechanism: alcohol is partially fat-soluble. When you combine a spirit with melted fat and let them sit, the fat releases its flavour compounds into the spirit. Cool the mixture below the fat's freezing point and the fat solidifies. Strain it out, and the flavour stays behind in the liquid. The technique was popularised at PDT in New York in the late 2000s; bartenders have been quietly using variations of it for over a decade since.
The basic method
- Melt your fat. Cook bacon for the rendered fat, or warm coconut oil, or brown butter on the stove. You want a fully liquid fat at room temperature or warmer.
- Combine in a clean jar: one part fat to about eight parts spirit by volume. Stir to disperse.
- Sit at room temperature for two to four hours. Stir occasionally. This is when the flavour compounds migrate from the fat into the spirit.
- Move the jar to the freezer for at least eight hours. The fat solidifies into a layer on top while the spirit stays liquid.
- Skim or strain off the fat layer. Pour the spirit through a coffee filter or fine mesh to catch any remaining particles.
- Bottle. The fat-washed spirit keeps in the fridge for several months.
Four fat-washes worth trying
Bacon bourbon. The classic. Cook six rashers of streaky bacon, strain the fat into a jar (about 50ml), add 400ml bourbon. Sit, freeze, strain. Use it in an Old Fashioned with maple syrup and orange bitters. The drink reads as breakfast in liquid form, but in a good way.
Brown butter rum. Brown 50g of unsalted butter in a small pan until it smells nutty and the milk solids turn golden. Cool slightly. Add to 400ml aged rum. Process as above. Excellent in a hot toddy or in a butterscotch-leaning old fashioned with demerara syrup.
Coconut oil vodka. Warm 60ml virgin coconut oil. Add to 400ml vodka. Process. The vodka picks up a clean coconut nose without the syrupy sweetness of coconut cream. Use in pineapple-based drinks for a tropical lift, or in a clear pina colada variant.
Olive oil gin. Warm 40ml good quality olive oil. Add to 400ml London Dry gin. Process. The gin smells distantly Mediterranean. Use in a savoury martini with a lemon twist and a single olive. We have poured this at Soluble Solids and it always sparks a conversation.
What works and what does not
Fats that work well: bacon, duck fat, butter (brown or regular), coconut oil, olive oil, sesame oil (use very small amounts), pumpkin seed oil, hazelnut oil. Anything with strong flavour and a low melting point.
Fats that do not work well: any fat that is rancid or stale, deep-fryer oil, anything with too much water content (cream, mayo). Fats with high melting points (palm shortening, lard from beef) are harder to strain cleanly.
Spirit pairings: bourbon and aged rum with savoury fats (bacon, butter, duck); vodka and gin with herbal and floral fats (olive, sesame, hazelnut); tequila and mezcal with smoky or roasted fats. Use white spirits for clean fat-washes and brown spirits for richer ones.
Where it goes wrong
The mistake we see most often at home is freezing too briefly. The fat needs to be fully solid before you strain. If any of it is still liquid you will get a greasy spirit. Eight hours minimum, twelve to be safe.
The second most common: using too much fat relative to spirit. More fat is not more flavour; it just leaves more fat to strain and risks emulsification. Start with 1:8 fat to spirit and adjust from there.
Third: not letting the fat melt and infuse for long enough at room temperature before the freeze. Two hours is the minimum we use. Four is better for subtle fats.
The Malaysian angle
This is where it gets interesting for us. Malaysian cooking is full of distinctive fats: pandan-infused coconut oil, ghee, the chilli oil from sambal, the fat from rendered chicken skin for Hainanese chicken rice. We have been experimenting with washing whisky in chilli oil and with washing rum in coconut-pandan oil. The results are not on any menu yet because we are still refining them, but if you ask we will sometimes pour a small experimental glass for guests who are curious.
One small note
Fat-washing is not about masking a spirit, it is about adding a layer. If you start with cheap bourbon and wash it in bacon fat you will get cheap bourbon that tastes of bacon. Start with a decent base. The technique amplifies what is already there; it does not fix it.
If you have a fat at home and a spirit you do not love drinking neat, this is one of the most satisfying experiments you can do in a weekend. The first time you taste your own bacon bourbon you will probably make three more washes in a row.
Frequently asked questions
What is fat-washing a spirit?
Fat-washing is a technique that infuses fat-soluble flavour compounds (bacon, brown butter, coconut oil, olive oil) into a spirit without leaving fat behind. You combine spirit with melted fat, let them sit at room temperature so the alcohol pulls flavour out of the fat, then freeze the mixture. The fat solidifies, you skim or strain it off, and the spirit is left with the aroma but no greasy texture.
How do I fat-wash bourbon with bacon at home?
Cook six rashers of streaky bacon and strain the rendered fat into a clean jar, about 50ml. Add 400ml bourbon (1:8 fat to spirit). Stir and sit at room temperature for two to four hours, stirring occasionally. Move to the freezer for at least eight hours, ideally twelve. Skim the solidified fat layer and pour the spirit through a coffee filter. Bottle and refrigerate.
Which fats and spirits pair best?
Bourbon and aged rum take savoury fats like bacon, duck, and brown butter beautifully. Vodka and gin work with herbal and floral fats: olive oil, sesame, hazelnut. Tequila and mezcal pair with smoky or roasted fats. Avoid rancid fats, fats with high water content like cream or mayonnaise, and high-melt fats like beef lard or palm shortening, which are hard to strain cleanly.
Can I substitute a cheaper spirit for fat-washing?
Yes, but the technique amplifies what is already in the bottle rather than masking faults. Start with cheap bourbon and you get cheap bourbon that tastes of bacon. A decent mid-tier base (Buffalo Trace, Plantation 3 Stars, Beefeater) gives a much better fat-washed result than a value-tier alternative. Save the premium bottles for sipping; mid-tier is the sweet spot for washing.
Where can I taste a fat-washed cocktail in PJ?
Ask at Dissolved Solids (43-1 Jalan SS20/11 Damansara Kim) or Soluble Solids (50-1 Jalan SS2/24) for the brown butter Old Fashioned or the olive oil Martini; both appear off-menu. We also pour experimental Malaysian-fat washes (pandan coconut oil rum, chilli oil whisky) on request. Message Dissolved Solids on WhatsApp +60 11-4008 7607 or Soluble Solids on +60 11-1682 8651.