Homebrew Beer Kegs: Cornelius, Ball Lock and Pin Lock Guide

Key takeaways

• Cornelius (corny) kegs are the most common choice for homebrewers because they are easy to clean, maintain and convert into home-dispense setups.
• Ball lock and pin lock kegs work on the same principle but use different gas and liquid posts, so you must match your disconnects and fittings to your keg type.
• Sanke kegs are standard in pubs and for many commercial mini-keg products, such as a San Miguel keg compatible with PerfectDraft machines, but they are less convenient for small-batch homebrew unless you invest in extra hardware.
• New stainless steel kegs offer predictable reliability, while reconditioned options can be great value if you are willing to inspect seals and posts and replace parts as needed.
• Safe kegging relies on good cleaning habits, correct pressure settings, and regular checks of seals and fittings to avoid leaks and over-pressure issues.

Why homebrew keg choice matters

Your choice of keg has a direct impact on how your beer tastes, how long it lasts, and how enjoyable your brewing hobby becomes. A well-designed keg system can give you consistent carbonation, clean pours and low oxygen exposure, all of which help your beer stay fresh from the first pint to the last. A poorly matched or awkward keg can lead to leaks, flat beer, over-foaming and a lot of unnecessary frustration.

Homebrew kegging also shapes what kind of setup you end up with. Cornelius kegs lend themselves to flexible, modular systems that can grow with you, from a simple single-keg fridge to a multi-keg kegerator. Sanke kegs, by contrast, push you towards a more commercial-style arrangement, which can be a good fit if you like using prefilled kegs or want a pub-like experience at home, but they are less forgiving if you frequently experiment with small batches.

Understanding ball lock and pin lock connections matters for compatibility too. Once you invest in a set of disconnects, gas lines and taps, swapping keg type later means replacing fittings or buying adapters. Taking a little time now to choose a system that suits your space, your budget and your brewing style will save you both money and effort over the long term.

How to choose the right homebrew keg

Start by thinking about batch size and storage space. If you usually brew around 19 litres, a 5-gallon Cornelius keg is a natural match, but if your fridge or kegerator is tight on height, a short, fat keg or even two smaller kegs might be more practical. Articles such as homebrew keg sizes from 1.5 to 5 gallons can help you visualise how different kegs fit into common fridges and keezers.

Next, decide whether you want the simplicity of ball lock or the slightly cheaper but less common pin lock route. Both systems work well, but ball lock fittings tend to be more widely available and are often used in modern kegging kits. Pin lock kegs are a good option if you find a batch of refurbished units at a good price, but you will need to commit fully to that connection type or use dedicated adapters. It is wise to read a focused comparison such as ball lock vs pin lock kegs before buying your first set.

You should also decide whether your keg will hold your own homebrew or pre-packaged beer. Purpose-made kegs designed for machines like PerfectDraft are ideal if you want ready-to-pour commercial beer, while Cornelius kegs are more suitable for fermenting, force-carbonating and serving your own recipes. In some cases, you may use both: a homebrew setup for your own beer and an additional tap or adaptor for prefilled mini-kegs.

Common mistakes when choosing and using kegs

A frequent mistake is buying kegs that do not fit your fridge, kegerator or keezer. Many new brewers assume all 5-gallon kegs are the same height and only discover clearance issues once they have drilled holes or installed taps. Always measure both the internal height and the door or lid clearance, and remember that gas lines, disconnects and taps add a little extra height on top of the keg.

Another pitfall is mixing ball lock and pin lock hardware accidentally. It is surprisingly easy to buy the wrong disconnects or to inherit mixed posts on a refurbished keg. Gas and liquid posts are not just different shapes; they are designed to prevent you accidentally swapping gas and beer lines. Double-check each keg’s connection type and label your disconnects clearly.

Cleaning and maintenance are also commonly underestimated. A keg that is only rinsed between batches can harbour residue and off-flavour-causing microbes. Proper keg care means full disassembly of posts and dip tubes on a regular basis, replacing O-rings that look worn or swollen, and occasionally deep-cleaning with a dedicated cleaner. Skipping these steps may not ruin every batch, but it will eventually catch up with you.

Cornelius kegs explained

Cornelius kegs, often shortened to corny kegs, were originally used in the soft drinks industry for syrup. Homebrewers quickly adopted them because they are built from stainless steel, have removable lids for easy cleaning, and use simple gas and liquid posts that accept quick-disconnect fittings. A standard 5-gallon corny keg holds most typical homebrew batches with a small amount of headspace for gas.

On top of the keg you will find a large oval lid sealed by a thick O-ring, a gas-in post connected to a short dip tube, and a liquid-out post connected to a long dip tube that reaches near the bottom of the keg. When you apply CO2 pressure via the gas post, beer is forced up the liquid dip tube and out to your tap. This basic design is the same whichever connection type you choose, which is why Cornelius kegs are so flexible and popular for homebrew.

Think of a Cornelius keg as a stainless steel pressure vessel designed around ease of access. If you can reach inside with a cleaning brush, you can usually keep it in good condition for decades.

Ball lock vs pin lock connections

Ball lock and pin lock kegs use the same internal layout but differ in how gas and beer lines attach to the posts. Ball lock kegs have smooth, notched posts that accept quick-disconnects which grip onto internal ball bearings. Pin lock kegs use posts with small external pins that match corresponding grooves in the disconnects. Both systems are secure and reliable when used correctly.

Ball lock equipment tends to be more common in modern homebrew shops and in complete homebrew kegging kits. If you are starting from scratch, ball lock is often the simplest choice because you can easily find replacement parts and compatible fittings. Pin lock kegs may be shorter and wider, which can be a benefit in some keezers and a problem in narrow fridges; they also commonly come from reconditioned soft drink stock.

If you ever end up with a mix of ball lock and pin lock kegs, adaptors are available, but they add cost and complexity. Ideally, pick one system and stick with it for your gas and liquid fittings, especially if you plan to run more than one keg at a time.

Sanke kegs and prefilled options

Sanke kegs are the standard kegs used by breweries and pubs. Instead of a removable lid and separate gas and liquid posts, they have a single spear going down the centre and a coupler that snaps onto the top. Gas goes in and beer comes out through the same assembly. For homebrewers, Sanke kegs are less convenient to clean because you must remove the spear if you want full access to the interior, and this can require specialised tools.

Despite this, some homebrewers enjoy using Sanke-style setups because they mirror the experience of serving beer in a commercial bar. You can also encounter Sanke technology in smaller prefilled kegs designed for countertop machines. For example, the San Miguel 6-litre keg for PerfectDraft machines uses a proprietary variation of this principle, giving you draught beer at home with minimal setup.

If you enjoy both homebrew and commercial beers, you may end up with a Cornelius system for your own recipes and a separate machine or tap for compatible mini-kegs such as a Stella Artois unfiltered PerfectDraft keg. These products are largely plug-and-pour: you do not need to worry about ball lock or pin lock connections at all.

Keg sizes for homebrew

The most common Cornelius keg size is 5 gallons, which holds the majority of homebrew batches. However, smaller kegs are very useful in practice. Kegs around 3 gallons are ideal for splitting batches, experimenting with different dry hops or flavour additions, or fitting into small fridges. Compact kegs between 1.5 and 2.5 gallons are popular for portable serving, taking beer to gatherings, or maintaining a low-profile setup in a kitchen fridge.

When planning a mixed-size keg fleet, consider your gas management and storage. A single CO2 cylinder and regulator can run multiple kegs if you use a simple gas manifold, and smaller kegs can tuck into corners of a keezer that might otherwise go unused. Articles focused on kegs and accessories for kegerators can help you see how different sizes and layouts fit together in real-world setups.

New vs reconditioned stainless steel kegs

New stainless steel Cornelius kegs offer peace of mind. You get fresh seals, known history, and usually a warranty. They are an excellent choice if you are starting your system from scratch and do not want to spend time inspecting, cleaning, and refurbishing each keg. New kegs may also have modern features such as laser-etched volume markings or slightly improved lid designs.

Reconditioned or used kegs, often ex-soft-drink stock, can offer substantial savings. However, they come with a few extra responsibilities. You should expect to replace all O-rings when the keg arrives, strip and clean the posts and dip tubes, and check for dings, bent handles or slightly warped lids. Many brewers are happy to trade that effort for a lower price, especially if they are building up a multi-keg system.

If you are unsure which way to go, it can help to read targeted advice such as new versus used Cornelius kegs, then decide based on your budget, your willingness to tinker, and the availability of local suppliers.

Cleaning, maintenance and spiles

Good keg hygiene is essential for reliable beer quality. After each batch, you should rinse the keg with warm water, then use an alkaline cleaner designed for brewing equipment. Fully disassemble the posts and dip tubes periodically, soak them, and scrub any stubborn deposits. Follow up with a no-rinse sanitiser directly before filling the keg with fresh beer.

Over time, O-rings can dry out, crack or absorb odours. Keep a small kit of replacement seals for your lids, posts and dip tubes so you can swap them at the first sign of wear. This is especially important for reconditioned kegs, where the original seals may be many years old.

If you ever work with casks or traditional barrels alongside your kegs, you may also need venting pegs (sometimes called porous spiles) to allow a controlled release of gas. A bulk pack such as a set of 38 mm soft wood venting pegs can be useful if you serve beer from barrels for events while still relying on kegs for everyday home use.

Safety, pressure and keg longevity

Kegs are pressure vessels, so treating them with respect is vital. Always ensure that your regulator is functioning correctly and that you understand the pressure range suitable for beer carbonation and serving. Never bypass safety features or apply uncontrolled gas pressure; doing so risks damage to your keg, lines, or even personal injury.

Most Cornelius kegs have a built-in pressure relief valve in the lid. Use this whenever you need to vent excess gas, whether during force-carbonation or when you are disconnecting gas lines. If your relief valve ever sticks, leaks or fails to operate smoothly, replace it promptly. Periodic inspections for corrosion, deep dents or cracks will further extend the life of your keg system.

With sensible handling, regular cleaning and occasional replacement of seals and fittings, a stainless steel keg can last for many years. Combining good hardware with sound kegging technique, such as that described in a dedicated step-by-step kegging guide, helps ensure consistent, safe and enjoyable pours.

Example keg-related products and where they fit

While this guide focuses on general keg types rather than specific models, it can be helpful to see how a few real-world products fit into the bigger picture. The following examples illustrate how prefilled kegs, homebrew equipment and cask accessories each play a role in different serving setups.

San Miguel 6L keg for PerfectDraft-style machines

A 6-litre San Miguel keg designed for PerfectDraft machines is a ready-to-serve option for those who want draught lager at home without managing their own cornies, CO2 cylinders or taps. You simply chill the keg, load it into the compatible machine and let the built-in pump and cooling system handle the rest.

This kind of keg is ideal if you are not ready to commit to full homebrew kegging but still want the feel of draught beer at home. The trade-off is that you cannot refill it with your own beer. If that sounds appealing, you can explore a 6-litre San Miguel draught keg as an example of this type of product, keeping in mind that your homebrew system would use Cornelius or Sanke kegs instead.

In a mixed setup, you might keep a compact PerfectDraft-style unit on a counter for commercial beers while your fermentation fridge and Cornelius kegs handle your own recipes elsewhere.

Stella Artois unfiltered 6L keg

A 6-litre unfiltered Stella Artois keg, also made for PerfectDraft machines, highlights how these prefilled options allow you to offer a variety of beers without increasing the complexity of your hardware. Swapping between a lager, an unfiltered option and other compatible styles is simply a matter of changing the keg in the machine.

This works well for hosting, where you may not have enough homebrew on hand or want to provide a recognisable brand alongside your own beers. A product like a 6-litre Stella Artois unfiltered keg can complement your kegging setup rather than replace it, giving guests options.

The key point is that these sealed kegs use proprietary fittings, not ball lock or pin lock disconnects, so they live alongside, rather than inside, your homebrew keg system.

Soft wood venting pegs for barrels

Soft wood venting pegs are not kegs, but they are relevant if you venture into cask-style serving. Traditional casks and some barrels require controlled venting to let excess gas escape and to allow air in during serving. Packs of porous spiles or venting pegs make this practical for events and small-scale cask service.

If you experiment with cask ale for special occasions while keeping Cornelius kegs for everyday homebrew, a product like a pack of soft wood venting pegs becomes a simple way to manage your barrels safely. It is an example of how kegging knowledge overlaps with traditional cellarmanship, especially around gas management and serving conditions.

For most homebrewers, this is an optional extra rather than a core part of a kegging setup, but it shows how flexible beer-serving systems can be once you understand the basics of pressure and dispense.

Conclusion

Choosing the right homebrew beer keg comes down to understanding how Cornelius, ball lock, pin lock and Sanke systems fit your space, budget and brewing style. Corny kegs remain the workhorse choice for homebrewers because they are easy to clean, straightforward to maintain and compatible with flexible home setups. Sanke-style kegs, by contrast, are better suited to prefilled or commercial-style serving, including compact 6-litre kegs designed for countertop machines.

By taking a little time to decide which connection type you prefer, what size kegs match your batch volumes, and whether new or reconditioned stainless makes more sense for you, you can build a system that serves you well for many brews. Alongside your main Cornelius kegs, you might also integrate prefilled options such as a draught lager keg for PerfectDraft machines or specialised accessories like venting pegs for occasional cask service. With a solid grasp of how these elements work together, you can enjoy reliable draught beer at home, tailored to your own tastes.