Starting with a mini keg setup for homebrew

What counts as a mini keg

Mini kegs are small pressurised containers for beer, typically between 2 and 10 litres. Most homebrew setups use stainless steel kegs of 4 to 5 litres with a screw-on cap. The cap holds a tap and a small regulator that takes 16 g carbon dioxide cartridges, or connects to a full gas cylinder. Some kits use cheaper 5 litre tin party kegs with a built-in tap, which are lighter but less durable.

The appeal is plain. Four 5 litre kegs hold a 20 litre batch. Each one fits on a fridge shelf, which is not true of a 19 litre Cornelius keg. In a small Indian flat with one fridge, that difference decides whether kegging is possible at all.

Mini kegs also make the step to draught beer cheaper and slower. You can start with one keg and fill the rest of the batch into bottles. If you like it, add more kegs batch by batch rather than buying a full kegerator on day one.

The kit you need

• The kegs. Stainless steel lasts years. Check that the keg and cap are rated for the pressure you plan to use.
• A dispensing cap with regulator. This lets you set and hold a steady pressure. A cap without a regulator relies on short bursts of gas, which makes carbonation hard to control.
• Carbon dioxide. 16 g cartridges are easy to find online but run out fast. A small refillable cylinder with an adaptor costs more at the start and far less per litre.
• Cleaning and sanitising kit. A bottle brush that reaches the bottom, an alkaline cleaner and a no-rinse sanitiser.

Two ways to carbonate

You can carbonate a mini keg with sugar or with gas. Natural carbonation adds priming sugar to each keg, much like bottling. The yeast ferments it over two weeks at room temperature. Because the keg has much less headspace per litre than a row of bottles, many brewers use less sugar than for bottles. Check the keg maker's guidance and use a priming calculator. Over-priming a small keg can bulge or damage it.

Force carbonation uses gas instead. Chill the full keg, connect the regulator, set the pressure for your target carbonation and wait about a week. It is faster and more controllable. Our guide to force carbonating with the set and forget method explains the pressures.

Filling without oxygen or yeast

Fill mini kegs straight from the fermenter tap or with a siphon. Run the tube to the bottom of the keg and let it fill from below so the beer does not splash. Leave a few centimetres of headspace. If you have gas, purge the headspace with a short burst of carbon dioxide before sealing. That pushes out most of the air, which matters for hoppy beers.

Leave the yeast behind. Beer drawn from above the sediment gives a clearer keg and a cleaner first pour. If you naturally carbonate, the yeast will settle on the bottom of the keg and the first glass will be cloudy. After that it pours clear.

Mistakes we see most often

• Serving warm. A mini keg on the counter at 30 °C pours mostly foam. Keep it in the fridge.
• Too much pressure on the tap. Serving pressure is usually a little lower than carbonating pressure. Turn it down before pouring.
• Leaving beer in the tap. Rinse the tap after each session. Beer left in it turns sour and sticky.
• Poor cleaning. The narrow neck of a mini keg hides residue. Clean it straight after emptying.

Our list of first homebrew mistakes covers more of the early traps.

A stepping stone or the final setup

Some homebrewers keep mini kegs for good. They suit small flats, small batches and parties. Others move on to Cornelius kegs and a kegerator once they brew more often. Either way you learn the basics of pressure, carbonation and clean dispensing that every draught system relies on. If you belong to a homebrew club, mini kegs are also the easiest way to bring beer to a meeting. Our guide to starting a homebrew club has ideas for those sessions.

Your first step: measure the height and width of your fridge's tallest shelf space. Choose a mini keg that fits it with the tap on before you buy anything else.