Pot still, reflux still or column: which is right for you?

The principle: how many times the vapour is refined

When a wash boils, its vapour is richer in alcohol than the liquid it came from. Condense that vapour and boil it again, and the result is richer still. Each boil-and-condense step is one stage of separation - what chemical engineers call a theoretical plate.

A pot still gives roughly one stage per run. A reflux column gives many: vapour rising through the column meets liquid running back down, and they exchange alcohol and other compounds again and again on the way. More stages mean a stronger, cleaner and more neutral spirit - up to the limit of the azeotrope, at about 96% ABV.

The pot still

A boiler, a short path for the vapour, and a condenser. Little or nothing refines the vapour on the way, so what comes out reflects the wash closely: its fruit, grain and character carry through.

• Strength: a single run of a typical wash gives low wines of around 25–35% ABV; a second run brings the hearts to roughly 60–80%.
• Cuts: the transitions are gradual, so the cuts are broad judgements - and that's where much of the craft lies. See making the cuts.
• Best for: whiskey, rum, brandy and other spirits made for flavour.

Some pot stills add a thumper (or doubler): a vessel between the boiler and the condenser in which the vapour bubbles through liquid, giving the effect of a second distillation in one run.

The reflux still

A tall column, packed with material that offers a large surface - such as stainless or copper mesh - or fitted with plates, sits on the boiler. At the top, part of the vapour is condensed and sent back down as reflux. The balance between what is returned and what is drawn off - the reflux ratio - sets how strong and clean the spirit is.

• Strength: commonly 90–95% ABV in a single run.
• Character: clean and neutral; most of the wash's flavour is left behind.
• Cuts: separation is sharp. The heads are concentrated early and the hearts run long and steady, but the tails arrive quickly once the column can no longer hold them.
• Best for: vodka, and neutral spirit for gin and liqueurs.

Ways of controlling the reflux

Home reflux stills are often described by how they control the draw-off:

• Vapour management (VM): a valve splits the vapour between the reflux and the product condenser.
• Liquid management (LM): all the vapour is condensed at the top, and a valve decides how much of the liquid is drawn off.
• Cooling management (CM): the amount of cooling at the top of the column decides how much vapour is returned as reflux.

The plated column

Instead of packing, the column holds a small number of plates - often three to six - each with a pool of liquid that the vapour bubbles through. Each plate acts roughly as one stage. With a few plates the spirit comes off strong and clean in one run while keeping much of the wash's character; many plated stills let you bypass or remove plates, so one still can behave more like a pot or more like a column.

• Strength: roughly 70–90% ABV in one run, depending on the number of plates and how they are run.
• Best for: flavourful spirits in a single run - whiskey, rum and brandy with a cleaner profile.

Side by side

Typical figures; the actual strength depends on the wash, the still and how it is run.

How to choose

• Mostly whiskey, rum or brandy? A pot still - perhaps with a thumper - is the natural choice, and the simplest to run well.
• Mostly vodka and gin? A reflux column gives a clean neutral in one run. For gin, a pot still is then ideal for the botanical run - see Odin's Easy Gin.
• A bit of everything? A modular still - a pot with an optional column, or a plated column with removable plates - covers most needs.

Whatever you choose, steady heat matters: a reflux column in particular depends on a stable balance between heating and cooling. See your element isn't the power on the label.

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