Carboys & Demijohns

Demijohns and carboys

A demijohn is a narrow-necked glass vessel. A carboy is the same idea, usually larger, and often in PET rather than glass. Both exist to do one job a plastic bucket does badly: hold a ferment quietly for weeks or months while it drops clear, without picking up scratches, flavours or air.

That is why wine, mead and cider use them and beer generally does not. A beer ferments hard, finishes fast and goes to bottle. A wine sits, throws sediment, gets racked off it, and sits again. You want to watch that happen, and you want a vessel that will not hold on to whatever was in it last.

Glass or PET

• Glass. Does not scratch, does not stain, does not hold odours, and you can see straight through it. The traditional choice and still the better one for anything ageing long term. It is heavy and it breaks, so handle a full one with respect.
• PET. Considerably lighter at the same volume, and it will survive being knocked. The trade is that plastic scratches, and a scratch is somewhere for bacteria to sit. Good for shorter ferments and for anyone who does not fancy lifting glass.

What is here

The 5 litre demijohns are the core of the range and come three ways: with a screw cap, with a handle and clip top lid, or bundled with bung, airlock and thermometer so there is nothing else to buy. There is also a 5 litre glass brewing kit that adds a syphon. Above that, an 11 litre glass carboy with bung and airlock, and a 23 litre PET carboy for full batches.

Five litres is the size most people should start with. It is one manageable batch, it uses an amount of fruit or honey you will not resent if the first attempt is ordinary, and it lets you run two different things at once rather than committing everything to one recipe.

Bungs, and getting the right one

This is where most orders go wrong, so it is worth being specific. Bungs are sized to the neck, not to the vessel's volume, and the sizes overlap confusingly.

• Rubber 26-32mm, solid or drilled. Suits a 2 litre flagon.
• Silicone 25-38mm, solid or drilled. The general purpose carboy bung.
• No. 10, 43-51mm, drilled. For the PET carboy.

Drilled takes an airlock, which is what you want during fermentation. Solid seals it completely, which is what you want once it is finished and ageing. Most people need both for the same vessel at different stages.

For fermenters, syphons, hydrometers and the rest of the gear, see our wine and fermenting equipment range.

Ships Australia-wide from our Melbourne store. If you are unsure which bung fits what you already own, ring us with the neck measurement rather than guessing from a photograph. It is the single most returned item in the shop and it does not need to be.