For anyone who enjoys a pint at the local, understanding what’s actually pouring from those taps can enhance our appreciation of Britain’s favourite tipple.
Whether you’re a seasoned ale enthusiast or simply curious about what you’re drinking, knowing the distinction between cask and keg beer can improve your enjoyment of it. So let’s dive into the fascinating world of beer storage before our significant others can remind us of how dull we are.
The Basics of Beer Storage
When we talk about beer storage, we’re essentially discussing how the golden nectar makes its journey from brewery to glass. The vessel that houses the beer plays a crucial role in determining its character, freshness, and overall drinking experience.
Throughout brewing history, various containers have been used to store and transport beer. From ancient clay amphorae to wooden barrels and modern metal vessels, each era has brought innovations in beer storage. Today, the two dominant methods in British pubs are cask and keg—each with distinct characteristics.
The storage method affects everything from carbonation levels to serving temperature, and ultimately, the flavour profile of your pint. Understanding these differences helps explain why the same beer might taste different depending on how it’s stored and served.
Beer storage isn’t just about preservation—it’s about presentation and sometimes even continuation of the brewing process itself. This is particularly true for cask ales, which continue to develop even after leaving the brewery.
Cask Ale: The Traditional Choice
Cask ale represents brewing heritage at its finest—a traditional method that has been cherished in British pubs for centuries. Often referred to as “real ale” by enthusiasts, cask-conditioned beer undergoes a fascinating journey before reaching your glass.
A traditional cask is a barrel-shaped container typically made from aluminium or stainless steel nowadays, though historically they were crafted from wood by skilled coopers. These vessels are designed to be stored horizontally, with a circular opening (the bunghole) where a tap is eventually inserted to draw the beer.
What makes cask ale special is that it’s a living product. When beer enters the cask, it hasn’t completed its journey—it continues to undergo secondary fermentation inside the vessel. The live yeast remains active, consuming residual sugars and creating gentle, natural carbonation. This process contributes to the distinctive character that cask ale aficionados love.
Unlike other beer serving methods, cask ale contains no added carbon dioxide or nitrogen. Instead, all carbonation occurs naturally through the ongoing fermentation process. This results in a softer mouthfeel and allows the subtler flavours to shine through without being masked by excessive fizz.
Keeping Cask Ale
Maintaining cask ale requires skill and attention to detail. The process begins when a cask arrives at the pub, where it needs proper handling before it’s ready to serve.
First, the cask must be “stillaged”—positioned correctly in the cellar to allow sediment to settle. Then comes “tapping” (inserting the tap) and “venting” (allowing excess gas to escape while keeping the beer in). This preparation process can take up to 48 hours before the beer is ready to serve.
Temperature control is crucial for cask ale. The ideal serving temperature ranges between 11-13°C (cellar temperature), which allows the full spectrum of flavours to be appreciated. Too cold, and the subtle notes are suppressed; too warm, and the beer can taste flat or overly yeasty.
Most cask ales contain finings—substances often derived from fish bladders or gelatin—that help clarify the beer by drawing yeast and protein haze to the bottom of the cask. This traditional practice means many cask ales aren’t suitable for vegetarians or vegans, though some breweries now offer vegetarian-friendly alternatives.
Once tapped, cask ale has a relatively short shelf life of about three days. This ephemeral quality is both a challenge for publicans and part of the charm for enthusiasts—a properly kept cask ale is a fresh, living product that captures a moment in time.
Understanding Keg Beer
Keg beer represents a more modern approach to beer storage and serving, designed with consistency and convenience in mind. Unlike its cask counterpart, keg beer is typically filtered, pasteurised, and stored under pressure.
A keg is usually a cylindrical stainless steel container with a single opening fitted with a valve system. This design allows gas (typically carbon dioxide, sometimes mixed with nitrogen) to be pumped in, pushing the beer out through the draught lines to the bar tap. This pressurised system is what gives keg beer its characteristic carbonation and longer shelf life.
The filtration and pasteurisation processes remove yeast and other particles, creating a clear beer with consistent flavour from the first pint to the last. While purists might argue this removes some character, it ensures reliability and stability—qualities valued by both publicans and many consumers.
Keg beer is typically served cold, at temperatures between 3-8°C. This chilled serving style enhances refreshment and accentuates the crisp, clean characteristics that keg beers are known for. It’s particularly suited to lagers, modern craft beers, and styles where a bright, effervescent quality is desirable.
Popular Styles in Keg Format
The keg format accommodates a wide range of beer styles, from traditional lagers to innovative craft creations.
Lagers dominate the keg beer world, with their clean, crisp profiles perfectly complemented by the cooler temperatures and higher carbonation levels that kegs provide. From classic pilsners to refreshing helles, the keg format showcases lagers’ bright characteristics.
Stouts and porters often appear in keg form, sometimes with added nitrogen for a smoother, creamier texture. This serving method creates the cascading effect and velvety head that many stout drinkers appreciate—think of the iconic pour of certain famous Irish stouts.
Modern craft beers, particularly American-influenced styles like IPAs, pale ales, and experimental brews, frequently utilise keg serving to maintain consistency and showcase hop aromas. The controlled environment of a keg helps preserve the volatile compounds that give these beers their distinctive characters.
Session ales and lower-alcohol options also benefit from keg serving, as the added carbonation can enhance the drinking experience of beers that might otherwise seem thin or lacking in body. This makes them perfect choices for longer pub visits when you’re looking to moderate your alcohol intake.
Cask vs Keg: Key Differences
So, to reiterate at a glance, the key differences between Cask and Keg are:
- Storage and Serving Temperature – Cask ales are typically served at cellar temperature (11-13°C) to emphasize flavour. Kegs are served much colder (3-8°C) for a more refreshing experience.
- Carbonation Method – The carbonation in cask ale develops naturally during secondary fermentation. Keg beer receives its carbonation through added pressure.
- Shelf Life – Once tapped, cask ale remains at its best for only about three days. Keg beer, being pressurised with minimal oxygen contact, can last for weeks without significant quality degradation.
- Preparation Requirements – Cask ale demands skilled cellar management, including stillaging, tapping, venting, and monitoring. Kegs are essentially ready to serve upon delivery, needing only to be connected to the gas and dispensing system.
- Flavour Profile – Cask ales typically offer more subtle, complex flavours with a softer mouthfeel and natural conditioning. Keg beers present brighter, more consistent flavours with pronounced carbonation that can enhance certain characteristics like hop bitterness or crisp finishes.
Choosing Between Cask and Keg
When faced with the choice between cask and keg at your local, several factors might influence your decision beyond simple preference.
Consider the occasion and setting—a cold, crisp keg lager might be perfect for a summer garden session, while a rich, complex cask ale could be ideal for a cosy winter evening by the pub fire. Different contexts call for different beer experiences.
Think about the specific beer style you’re in the mood for. Some styles simply shine brighter in one format than the other—traditional British bitters often express themselves beautifully in cask, while Czech pilsners typically benefit from the carbonation and temperature control of keg serving.
Trust the reputation of the establishment. A pub known for excellent cellar management will serve cask ales in peak condition, while one with high-quality keg lines and proper glass washing will showcase keg beers at their best.
Don’t be afraid to experiment and expand your palate. Many beer enthusiasts appreciate both cask and keg offerings for different reasons, recognising that each has its place in British pub culture.
You don’t have to be a cask man or a keg man, you can be both.
