Kegging Your Home Brew: Pressure Barrels, Cornelius Kegs & Keezers

Should You Keg or Bottle Your Home Brew?

Kegging saves significant time over bottling: instead of washing, filling and capping dozens of bottles, you do a single transfer and have fresh draught beer from the tap. If you brew more than once a month, a keg system pays for itself quickly in time saved and better beer. If you brew occasionally, bottling with carbonation drops is perfectly fine.

There are two main routes: a simple pressure barrel, or a Cornelius keg system with CO₂. Here's how each works.

Pressure Barrels — The Simple Option

A pressure barrel is a sealed plastic vessel that stores and serves beer under light CO₂ pressure: the simplest kegging option for UK home brewers.

  1. Confirm fermentation is complete with a hydrometer before transferring; kegging too early causes over-pressurisation.
  2. Sterilise the barrel thoroughly with Young's Steriliser.
  3. Siphon the beer in gently, to minimise splashing and oxygen exposure.
  4. Add around 80g of brewing sugar to prime it, then seal.
  5. Leave 7–14 days to condition. Connect a CO₂ charger to restore pressure when serving.

See our full guide: How to Use a King Keg, and our conditioning guide for timing by style.

Cornelius Kegs — The Serious Option

The Cornelius keg ("corny keg") was originally used by the soft drinks industry and has been widely adopted by home brewers. They come in two post types:

  • Ball lock – the more common type; gas and liquid posts are different sizes, so they can't be mixed up.
  • Pin lock – older-style, still compatible with standard CO₂ systems.

A standard 19 litre (5 gallon) corny keg holds around 33 pints. 9.5 litre mini kegs suit tighter spaces.

What You Need

  • Cornelius keg – clean and pressure-tested
  • CO₂ cylinder – 2kg is a sensible starting size
  • Dual-gauge regulator – one gauge for cylinder pressure, one for serving pressure
  • Beer line and tap – typically 3/16" ID line and a picnic tap or kegerator tap
  • Food-grade silicone keg lube and spare O-rings, which are cheap and worth keeping on hand

Keezer or Kegerator?

Your keg needs to stay cold, ideally 3–5°C for most styles.

  • Kegerator: a converted upright fridge with a tap tower. Neater, but can struggle to fit full-size corny kegs in some domestic fridges.
  • Keezer: a chest freezer fitted with a temperature controller run at fridge temperatures, with a wooden collar to mount the taps. More capacity, easier to fit multiple kegs, and often cheaper second-hand. The most popular setup among serious UK home brewers.

Force Carbonation: Two Methods

Once the beer is in the keg and the headspace purged with CO₂:

  • Slow & set: set the regulator to serving pressure (typically 10–12 PSI for most ales and lagers at 4°C) and leave for 5–7 days. Hands-off and very consistent.
  • Quick carbonate: set the regulator to 30 PSI, lay the keg on its side and roll or rock it for 5–10 minutes, then drop to serving pressure for a few hours. Pouring within an hour, though slightly less even if rushed.

Use a carbonation calculator to find the right PSI for your target CO₂ level and serving temperature.

Balancing Your Beer Lines

Line balancing matches the resistance in your beer line to your serving pressure, so it pours without excessive foam or a flat, slow pour.

  • 3/16" ID beer line gives roughly 3 PSI of resistance per foot (≈ 0.9m)
  • At 12 PSI serving pressure, around 4 feet (1.2m) of line balances the pour
  • Too foamy: lengthen the line. Too flat and slow: shorten it.

A warmer keg needs higher serving pressure to hold the same carbonation, which then needs a longer line to balance, so keeping temperature consistent makes the maths much easier.

Getting Clarity on Tap

  • Cold crash the fermenter to 1–2°C for 48–72 hours before kegging to drop yeast and haze.
  • Use beer finings before cold crashing.
  • Transfer via a closed, CO₂-purged transfer to minimise oxygen pickup, especially for hop-forward beers like NEIPAs.
  • The first pull from a new keg is often cloudy; discard half a pint and the rest should pour clear.

Keg Maintenance and Cleaning

  • Rinse with hot water immediately after emptying.
  • Fill with a sodium percarbonate cleaner solution and leave 30–60 minutes, then rinse thoroughly.
  • Inspect O-rings on the lid, posts and poppets; replace annually or at the first sign of cracking.
  • Sanitise with a no-rinse sanitiser before filling, then pressurise with CO₂ and check the seals with a sanitiser spray for leaks.

Pressure Barrel vs Cornelius Keg: Which to Choose?

Pressure barrel Cornelius keg
Upfront cost Lower Higher (keg + CO₂ + regulator + fridge)
Setup Simple More involved
Carbonation control Basic Precise, adjustable
Best for Occasional brewers, simplicity Regular brewers who want full control

Long-term, kegging saves money on consumables too, like crown caps and carbonation drops, on top of the time saved. For a full breakdown, see our cost per pint guide.

Browse our full kegging and draught equipment range at BrewCo.

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