The Difference Between Cask and Keg Beer

Things that characterise real ale in pubs:

1. Temperature: You’ll find most cask ales are best drank when they’re served around 11-13 degrees. This is typically the temperature of the cellar where the beer has been stored and allows the full flavours of the beer to be released.

2. Serving: Cask beer is often dispensed using a gravity-fed system or from a traditional hand-pump where the beer is pulled directly from the cask and into the glass being filled. It’s a pretty simple setup but means the beer is being served direct from cask to glass. You’ll find these setups almost always include a sparkler on the dispensing nozzle to produce a long lasting, and creamy head to the beer, but whether or not to use one is an age old debate, separating North & South!

3. Freshness: As with all food and drink, there’s an optimal time frame during which it is in peak form, and cask beer is no different; it’s classed as a live product, after all! With most real ales, once the cask has been opened and is being served on the bar, the beer is at its best for around 3-4 days. A good cellar manager will be tasting the beer every day before service to check for quality, as off-flavours can begin to creep in as the beer ages (not a bad job if you ask me…)

4. Flavour Profile: Cask beer drinkers appreciate the nuanced flavours and aromas from this style of beer. The natural conditioning process allows the beer to develop complex tastes over time and the lack of additional carbonation during this process allows the subtle flavours of the beer to shine through.

Key characteristics of keg beer:

1. Carbonation: Unlike cask beer, which naturally carbonates in the cask, keg beer is artificially carbonated during kegging. This is typically achieved by injecting carbon dioxide (CO2) and sometimes nitrogen into the beer under pressure, resulting in a higher level of carbonation compared to cask beer.

2. Temperature: Keg beer is usually stored and served at colder temperatures, normally around 3-7 degrees Celsius. This is primarily to keep the CO2 in solution while being served but has other benefits – the main one being that the resulting beer is crisp, refreshing and very satisfying to drink, especially on a hot summer’s day!

3. Pressure: Keg beers are dispensed under pressure, using a gas powered system (either by CO2 or nitrogen) that applies pressure to push the beer through the tap.

4. Shelf Life: Whilst cask beer has a relatively short shelf life after being tapped, kegged beers have a much greater shelf life. The filtration process it undergoes helps to preserve the beers freshness, allowing it to be served over a much longer period. Depending on filtration levels and whether or not the beer is pasteurised, it can be up to a few weeks (but as brewers you’d always hope a keg was done in a week!)

5. Consistency: Properly cared for keg beer can potentially offer greater consistency in terms of flavour, carbonation, and appearance from the start of the keg to the end, thanks to the lack of yeast present and the addition of a CO2 blanket on top of the beer that reduces oxidisation.