Distilling Glossary: Terms Explained from A to Z

Australian legal note: In Australia, using a still of any size to distil alcohol requires an excise manufacturer licence, and the ATO does not grant licences to distil spirits for personal consumption. Stills over 5 litres also need ATO permission to own. Brewing beer, cider and wine at home for non-commercial use needs no licence. This glossary is for education, for non-alcohol uses of stills such as water and essential oils, and for licensed operations. See the ATO's guidance on stills for the current rules.

Distilling has its own language, and a lot of it comes from centuries of practice in places like the farmhouses of northern Italy, the Scottish Highlands and the Caribbean. Words like heads, feints, dunder and parrot make perfect sense once someone explains them, and very little sense before. This glossary pulls the common terms into one place, grouped alphabetically, with links to our deeper guides where you want to read more.

Bookmark it, and if a term you have come across is missing, ask us in store at Laverton North or Epping and we can look at adding it.

A to C

ABV (alcohol by volume)

The percentage of a liquid's volume that is pure alcohol. A 40% ABV spirit is 40% ethanol and 60% everything else, mostly water. See How Standard Drinks Are Calculated for how ABV links to standard drinks.

Airlock

A one-way valve fitted to a fermenter lid. It lets carbon dioxide escape during fermentation while keeping air, insects and wild microbes out.

Alcoholmeter (alcoholometer)

A hydrometer calibrated to read alcohol percentage directly, for mixtures of only alcohol and water at a set reference temperature. It cannot read a sugary wash or a liqueur. See Alcoholmeter vs Hydrometer.

Alembic

The traditional pot still: a boiler, a domed head, a neck and a condenser, usually in copper. The word comes through Arabic al-anbiq. Read more in Copper Stills and Alembics Explained or browse our Alembic Pot Stills.

Azeotrope

A mixture that boils without changing composition. Ethanol and water form one at roughly 95.6% ethanol by weight, which is why ordinary distillation cannot produce 100% pure alcohol.

Backset

Spent liquid from a previous distillation added to a new fermentation, to adjust acidity and add character. This is the basis of the "sour mash" process used for some American whiskeys.

Barrel chunks

Pieces of oak cut from used barrels, used to give spirit wood character in a jar or demijohn. See Ageing Spirits with Oak.

Boiler

The vessel that holds and heats the liquid being distilled. It may be heated by an electric element, gas or a flame. See our Heated Boilers and Fittings.

Botanical basket

A perforated container that holds herbs, spices or peel in the vapour path of a still, so the vapour picks up aroma on its way to the condenser. Used for gin-style spirits and aromatic waters. See our Botanicals range.

Bubble plate

A plate inside a column still with caps or holes that hold a layer of liquid. Vapour bubbles through each plate, and each plate acts like a small additional distillation. See the copper bubble plate assembly.

Carbon filtering

Passing spirit through activated carbon to remove unwanted flavours and aromas. Common for neutral spirit before flavouring. See the Smart Carbon Filter by Pure Distilling.

Column

The vertical section above a boiler where vapour rises and partly condenses, separating components more finely. Taller and packed columns give cleaner, stronger spirit. See Pot Still vs Reflux Still vs Air Still.

Condenser

The part of a still that cools vapour back into liquid, usually with cold water flowing around a tube or coil. Air-cooled designs use a fan instead.

Copper

The traditional still metal. Besides conducting heat well, copper reacts with sulphur compounds in the vapour, which reduces eggy, rubbery off-aromas in the distillate.

Cuts

Dividing the output of a run into fractions: foreshots, heads, hearts and tails. See Making Cuts: Heads, Hearts and Tails.

D to F

Dephlegmator

A small condenser at the top of a column that sends some vapour back down as liquid. That returning liquid, called reflux, increases separation and purity.

Dilution

Adding water to bring spirit down to drinking or bottling strength. See Understanding Alcohol Dilution and the Spirits Calculators.

Distillate

Anything that comes out of the condenser. Also simply called the output.

Distilled water

Water that has been boiled and condensed, leaving minerals and most impurities behind. Making it is a common non-alcohol use for a small still. See How to Make Distilled Water at Home.

Distillers yeast

Yeast selected for fermenting washes for distillation. Some are bred for flavour (rum, whiskey), others for strength and speed. See Turbo Yeast vs Distillers Yeast and our Distilling Yeasts.

Dunder

The leftover liquid in the boiler after a rum distillation, traditionally reused in later rum fermentations for flavour. Similar in idea to backset.

Essence

A concentrated flavouring added to neutral spirit to make a particular style, such as a gin, whisky or liqueur profile. See our Essences.

Essential oil

The concentrated aromatic oil carried out of plant material by steam. Distilling herbs and flowers produces essential oil and hydrosol. See Essential Oils and Hydrosols with a Still.

Ethanol

The drinking alcohol produced by yeast. It boils at about 78°C, well below water, which is what makes distillation work.

Excise manufacturer licence

The ATO licence needed to manufacture spirits in Australia. The ATO states that a licence is needed to use a still of any capacity to distil alcohol, that there must be a commercial purpose, and that it does not grant licences for personal consumption. See the ATO's guidance.

Feints

The heads and tails fractions, often collected together and set aside rather than kept with the hearts. Usage varies, and some people use the word for the tails only. In licensed operations feints may be added to a later run.

Fermentation

Yeast converting sugar into alcohol and carbon dioxide. Brewers ferment wort and winemakers ferment must. A fermented liquid destined for the still is called a wash. See Sugar Washes Explained.

Final gravity (FG)

The specific gravity reading once fermentation has finished. Compared with original gravity, it tells you roughly how much alcohol was made. See Understanding Wash Gravity Readings.

Foreshots

The very first liquid out of a still. It carries the most volatile compounds, with sharp, solvent-like aromas, and is always discarded.

Fusel oils

Heavier alcohols produced especially by stressed or hot fermentations. They tend to concentrate towards the tails and give harsh, hot, solvent-like flavours.

G to L

Grappa

Italy's spirit distilled from pomace, the skins, seeds and stems left after winemaking. Grappa is a protected name tied to Italy. See Grappa Explained.

Heads

The fraction after the foreshots. Heads smell sharp and solvent-like, a bit like nail polish remover, and are usually separated from the hearts.

Hearts

The middle, cleanest fraction of a run, and the part that is kept as the finished spirit.

Hydrometer

A weighted glass float that measures the density (specific gravity) of a liquid. Used on wort, must and wash to track fermentation. See How to Take a Hydrometer Reading and our Hydrometers and Refractometers.

Hydrosol

The fragrant water collected alongside essential oil when distilling plants, such as rose water or lavender water.

Infusion

Steeping fruit, herbs, spices or oak in spirit to draw out flavour, with no still involved. A legal and approachable way to make liqueurs from commercially bought spirit. See Blending Spirits and Liqueurs.

Liqueur

A sweetened, flavoured spirit. Many are made by blending spirit with a liqueur base or essence. See Still Spirits Bases Explained.

Low wines

The product of a stripping run: a weaker, rougher spirit that is usually distilled a second time.

M to P

Mash

A fermentable mix of cooked grain and water, as used for whiskey. Fruit-based fermentations are also sometimes called mashes.

Methanol

A toxic alcohol that forms in small amounts during fermentation, mainly from pectin in fruit. Fruit and pomace ferments produce more than a sugar wash. Methanol boils at a lower temperature than ethanol (about 65°C), so it is often linked with the foreshots, although in practice small amounts come through across a run.

Neutral spirit

High-strength spirit with very little flavour of its own, used as a base for gin, vodka and liqueurs.

Oak

The wood used to age spirits, adding colour, vanilla, spice and tannin. French and American oak give different results. See Ageing Spirits with Oak and our Oak Chips, Staves and Planks.

Original gravity (OG)

The specific gravity of a wash, wort or must before fermentation starts. A higher OG means more sugar and more potential alcohol.

Packing

Material inside a column, such as copper or stainless steel saddles or mesh, that gives vapour more surface to condense on and improves separation. See the copper saddles and copper mesh.

Parrot

A small fitting under a still's output that holds an alcoholmeter in the running spirit, so strength can be watched during a run. See the stainless steel parrot.

Pomace

The skins, seeds and stems left after pressing grapes. In Italy it is the raw material for grappa. See Grappa Explained.

Pot still

A simple still where vapour rises from the boiler straight to the condenser with little reflux. It keeps more flavour, which suits whisky, brandy, rum and grappa. See Pot Still vs Reflux Still vs Air Still.

Proof

An older way of expressing alcohol strength. In the US system, proof is double the ABV, so 80 proof is 40% ABV. The old British system was different: 100 UK proof is about 57% ABV. Australia labels in % ABV.

Q to S

Reflux

Vapour that condenses inside the still and runs back down instead of leaving. More reflux means more separation, giving a lighter, purer spirit.

Reflux still

A still with a column designed to create lots of reflux, producing high-strength, clean spirit. See Pot and Reflux Stills and Accessories.

Specific gravity (SG)

The density of a liquid compared with water, which reads 1.000. Sugar raises it, alcohol lowers it.

Spirit run

The second, slower distillation that turns low wines into finished spirit, with careful cuts.

Still

Any apparatus that heats a liquid, collects the vapour and condenses it back into liquid. Stills are used for water, essential oils and, under licence, spirits. In Australia, the ATO requires permission for stills over 5 litres, and you can have a still of 5 litres or less without permission only if you are not using it to distil alcohol. See Home Distilling in Australia: A Beginner's Guide.

Still permission

Separate from an excise licence, the ATO's permission needed to manufacture, move, set up, sell, buy, import or possess a still over 5 litres, if you are not a licence holder. Penalties apply without it. Check the ATO page before buying.

Stripping run

A fast first distillation that pulls most of the alcohol out of a wash with no fine cuts. The result is low wines.

Sugar wash

A simple fermented liquid of water, sugar, yeast and nutrients. See Sugar Washes Explained.

T to Z

Tails

The last fraction of a run. Lower in alcohol, oily, with wet cardboard or wet dog aromas. Usually separated from the hearts.

Turbo yeast

A high-performance yeast blend packed with nutrients, designed to ferment large amounts of sugar quickly to a high alcohol wash. See Turbo Yeast vs Distillers Yeast.

Wash

The fermented liquid that goes into the still, usually made from sugar, grain or fruit. See Sugar Washes Explained.

Worm

A coiled copper condenser tube sitting in a tub of cold water. The classic condenser on traditional alembics. See our Alembic Pot Stills.

Frequently asked questions

What is the difference between heads, hearts and tails?

They are the three main fractions of a run. Heads come early and smell sharp, hearts are the clean middle that is kept, and tails come last and are oily and flat. Foreshots, the very first drops, are always discarded. See Making Cuts.

Is a pot still the same as an alembic?

An alembic is a traditional style of pot still, usually copper with a domed head. All alembics are pot stills, but not every pot still is an alembic.

Do I need a licence to own a still in Australia?

Stills over 5 litres need ATO permission. A still of 5 litres or less can be owned without permission only if it is not used to distil alcohol. Distilling alcohol with any still needs an excise manufacturer licence. Check the ATO page for the current rules.

What is the difference between a hydrometer and an alcoholmeter?

A hydrometer reads density in a sugary liquid. An alcoholmeter reads alcohol percentage in a mixture of only alcohol and water. See Alcoholmeter vs Hydrometer.