Infusion in Cocktail Making: the Guide to Spirit Infusion Methods

Infusion in Cocktail Making: What It Is and How It Really Works

Infusion in cocktail making is the process of transferring aroma, flavour and, sometimes, colour from a solid ingredient (herbs, spices, fruit, fats) into a liquid — usually a spirit or a syrup — to create custom bases that go beyond the commercial bottle. At STILLROOM we don’t talk about a single technique, but about a family of methods that share a common principle and that we master from our laboratory bar at Calle Moreto 9, beside El Retiro: cold maceration, infusion with controlled heat (sous-vide), fat washing and rapid infusion. Each responds to a different goal, and in this guide we explain the complete map so you understand when and why to use each method when infusing spirits.

Knowing these cocktail infusion methods lets you work with the precision of a technical bartender, whether you want to know how to infuse gin quickly for a weekend cocktail or you’re after the delicate extraction that only sous-vide can offer. It’s not magic: it’s physics applied to flavour.

What Happens During an Infusion: the Physics of Flavour

When we infuse, the aromatic and flavour compounds of the ingredient — essential oils, aldehydes, tannins, lactones — migrate into the liquid through a phenomenon of osmosis and solid-liquid extraction. In simple terms: the alcohol (or the water, in a syrup) acts as a solvent and breaks down the ingredient’s cell walls, releasing its soluble molecules. The fascinating thing is that this same principle governs everything from a three-week cold maceration to a five-minute rapid infusion.

At STILLROOM we’ve found that any infusion, regardless of the method, is governed by five variables that every technical bartender must control:

• Time: dictates how much extraction takes place. More time isn’t always better; it can saturate or turn bitter.
• Temperature: speeds up the transfer by increasing the kinetic energy of the molecules. Cold preserves volatile aromas; controlled heat extracts in depth.
• Contact surface: a greater exposed area (fine cuts versus large pieces) speeds up the infusion.
• Medium: the alcohol content, the proportion of water and the presence of fats determine which compounds are extracted.
• Agitation: helps homogenise the liquid and renew contact between the solvent and the surface of the ingredient.

Understanding these variables is what has allowed us to develop everything from delicate chamomile infusions in gin (just two hours at 55°C in sous-vide) to a fat washing with browned butter that lends silkiness and umami without muddying the drink. The same physical principle, applied with surgical precision, gives completely different results.

Infusion Methods: a Comparative Map

The table below shows the four main infusion methods we use at STILLROOM. They aren’t watertight compartments; we often combine steps (for example, a prior maceration that is then vacuum-sealed), but to understand the family it’s worth distinguishing them clearly:

Infusion method	How it works	Approximate time	Ideal for
Cold maceration	The ingredients rest in the spirit at room temperature or in the fridge, releasing their compounds slowly and without degrading volatile aromas.	From 2 days to 3 weeks	Fresh fruit, delicate herbs, hard spices (cinnamon, vanilla), notes that build over time.
Sous-vide (controlled heat)	Liquid and ingredients are vacuum-sealed and submerged in a water bath at an exact temperature (usually between 45°C and 65°C). The combination of heat and the absence of oxygen speeds up the infusion with no loss of aroma.	From 30 minutes to 3 hours	Teas, flowers, roots, delicate extractions where absolute repeatability and precise timing are required.
Fat washing (fat infusion)	A fatty ingredient (butter, olive oil, coconut wax) is emulsified with the spirit and then chilled to separate the solid fat. The alcohol captures the fat-soluble flavour molecules while the fat softens the alcohol’s sharpness.	From 2 to 24 hours of contact, plus 6-12 hours freezing	Adding silkiness, umami and toasted, dairy or nutty notes without clouding the final drink.
Rapid infusion	Intense agitation, controlled direct heat or pressure (such as a whipped-cream siphon) is applied to force the extraction within minutes.	From 3 to 15 minutes	Live service, express creations, when an infused base is needed during service without losing freshness.

Infusing spirits with these methods isn’t just a question of speed or patience. It’s about choosing which aromatic profile we want to highlight, what texture we’re after and what degree of control we need for the infusion to be replicable, especially in a signature cocktail-making context where every drink counts.

Which Method to Choose Depending on Your Goal

The question isn’t generic; it’s specifically “what do I want to achieve?”. We’ve organised the most common goals when infusing spirits for cocktail making, along with the method that best solves each one:

Goal	Recommended method	Example at STILLROOM
Floral or delicate aromas (elderflower, jasmine, chamomile) without bitterness	Sous-vide	Chamomile-infused gin at 55°C for 90 minutes; ultra-clean, with no harsh tannins.
Fatty, umami or toasted notes (butter, sesame, coconut, olive oil)	Fat washing	Aged rum with browned butter and a touch of vanilla, which we then clarify for the Dry&Stormy.
Whole spices or firm-fleshed fruit (cinnamon, cardamom, red berries)	Cold maceration	Vodka macerated with raspberries for 6 days; we then adjust it with an in-house cordial.
Speed and immediate freshness (fresh herbs, zest, soft fruit)	Rapid infusion	Gin infused in a whipped-cream siphon with basil and lemon in just 4 minutes for a seasonal cocktail.

This table isn’t an iron-clad dogma, but it is a starting point we’ve validated batch after batch at our bar in Los Jerónimos. Signature cocktail making benefits enormously when we understand that how to infuse gin, for example, doesn’t have a single correct answer: it depends on whether you’re after an ethereal note of tea or the punch of pink pepper.

How We Use It at STILLROOM: the Family of Methods in Action

In our liquid kitchen at Calle Moreto 9, infusion is never an end in itself, but a tool that connects several techniques. We rarely design a cocktail without deciding which method in the family best resolves the profile we’re imagining. We’ll tell you how we integrate each technique into our workflow, because we like you to know that behind every drink there are hours of trial with controlled variables.

Precision sous-vide infusions are our go-to when we need absolute repeatability, aromatic cleanliness and extraction without oxidation. We use them for tea, flower and root infusions where one extra degree would ruin the nuances. When the project calls for time and complex layers of flavour, we turn to maceration, which lets us build fruit, spice or unexpected-combination bases over weeks. If the goal is texture and umami — that drink that caresses the palate — we apply fat washing, a technique that stirs real passion in the team for the way it rounds off a spirit without masking it. All of these belong to a wider ecosystem of advanced cocktail-making techniques that you can explore in our laboratory.

Three Ideas to Start Infusing Spirits at Home (or Behind Your Own Bar)

If this map has given you the urge to get your hands dirty, here are three simple routes we’ve tried ourselves that show how each method pushes flavour in a different direction:

Sous-vide Gin Infused with Green Tea and Jasmine

Place 350ml of London Dry gin and 5g of good-quality jasmine green tea into a vacuum bag. Seal it, set your bath to 52°C and leave to infuse for 70 minutes. Strain through a fine-mesh sieve and taste. The result is floral, elegant and without a trace of bitterness. Perfect for a modified Martini or a Gin and Tonic with a neutral tonic that lets the infusion speak for itself.

Fat-Washed Rum with Browned Butter

Melt 60g of unsalted butter until it begins to brown and gives off a hazelnut aroma. Pour it, still liquid, over 350ml of aged rum in a jar; shake for a minute and leave to rest for 3 hours at room temperature. Freeze the whole thing for at least 12 hours, remove the solid fat and filter through a coffee filter. The resulting rum is silky, toasted and has an incredible depth, perfect for an Old Fashioned or simply to drink over ice.

Vodka Macerated with Sichuan Pepper and Juniper

In an airtight jar, combine 500ml of good-quality vodka with a tablespoon of lightly crushed Sichuan peppercorns and four juniper berries. Store in the fridge and taste every day from day 2 onwards. We like it between the fourth and sixth day, when a citrusy, tingling sensation appears that livens up any cocktail with soda or tonic. Strain well and bottle; it keeps for weeks in the fridge.

The Next Step: Try It, Share It and Come to Our Laboratory

Now that you have the map of the cocktail infusion family, it’s your turn to choose a route. You don’t need a professional laboratory: it’s enough to start experimenting with one variable at a time. When you want to see how this theory translates into real signature cocktails, we’re waiting for you at our cocktail menu, where every drink is a direct consequence of mastering these techniques. And if the plan appeals, you can book a table at STILLROOM, right in the heart of Los Jerónimos, to experience it up close.

If you’ve found this content useful, we recommend you keep exploring our cocktail glossary, where we break down every concept with the same technical depth and the same warmth.