What a Forty of Beer Actually Is
Let’s cut to the chase: a forty of beer is simply a 40‑liter keg that holds roughly 107 standard 12‑ounce bottles or cans. In other words, it’s the most efficient way to serve a crowd without constantly refilling glasses. The term comes from the keg’s volume—40 liters—mirroring the familiar “forty‑inch” truck size, and it’s become shorthand among bars, festivals, and home‑brew enthusiasts for a full‑size, party‑ready container.
Most people think “forty” refers to a specific brand or a fancy craft brew, but it’s actually a size designation that can be filled with any style, from light lagers to hoppy IPAs. Whether you’re planning a backyard BBQ, a wedding reception, or a pop‑up bar at a music festival, the forty‑liter keg offers a predictable, cost‑effective solution for serving large groups.
How a Forty Is Made: From Grain to Keg
The production process for a forty of beer doesn’t differ from any other batch; the key difference is the volume of the final packaging. Brewers start with malted barley (or alternative grains), water, hops, and yeast. After mashing, boiling, and fermenting, the beer is filtered and carbonated before being transferred into a stainless‑steel 40 L keg.
Most commercial breweries use a closed‑loop filling line that sanitizes the keg, pumps the beer in under pressure, and seals it with a standard Sankey coupler. This ensures the beer stays fresh, carbonated, and protected from oxygen exposure. For craft brewers, the same equipment can be used, but they often hand‑fill the kegs to preserve delicate aromatics, especially for hoppy or barrel‑aged beers.
Styles That Shine in a Forty
Because the forty can hold any beer, the choice of style depends on your audience and the event’s length. Here are three reliable categories:
Session Lagers – Light, crisp, and low‑alcohol (3–4% ABV), they keep guests drinking without getting overly intoxicated. Perfect for daytime festivals or outdoor picnics.
American‑style IPAs – If your crowd loves bold hop character, a well‑balanced IPA in a forty will stay aromatic thanks to the keg’s airtight seal. Aim for a slightly lower IBU (45–55) if the keg will sit for more than a few hours.
Belgian Saison or Farmhouse Ale – These medium‑bodied, spicy brews work well for evening events where you want something a bit more complex but still drinkable.
Don’t let the myth that “kegs are only for cheap lager” steer you; high‑end craft breweries regularly ship limited‑edition barrels in forty‑liter kegs for special releases.
What to Look for When Buying a Forty
First, verify the keg’s material. Stainless steel is the industry standard—galvanized or aluminum kegs can impart off‑flavors. Next, check the coupler type. In North America, most kegs use a Type D (Sankey) coupler, while Europe often uses a Type S. Make sure your tap system matches the coupler to avoid costly adapters.
Second, consider the beer’s freshness date. Kegs are best consumed within 30‑45 days of packaging, especially for hop‑forward styles that degrade quickly. Ask the supplier for a “first‑draw” date and plan your event accordingly.
Finally, evaluate the price per litre. Because a forty holds 40 L, the per‑litre cost is usually lower than buying cases of bottles. However, hidden fees—delivery, keg deposit, and cleaning—can add up. Calculate the total landed cost before committing.
Common Mistakes People Make With a Forty
Mistake #1: Ignoring Temperature Control – Beer served too warm loses carbonation and flavor. A forty should be stored at 38‑40 °F (3‑4 °C) in a walk‑in cooler or a dedicated kegerator. Many first‑time users place the keg on a regular refrigerator shelf, which can’t maintain a stable temperature over 40 L.
Mistake #2: Over‑Carbonating or Under‑Carbonating – Unlike bottles, kegs rely on pressure settings. Too much pressure (over‑carbonation) creates a foamy mess; too little (under‑carbonation) leads to flat beer. Use a regulator set between 10‑12 psi for most ales and 12‑14 psi for lagers.
Mistake #3: Forgetting the Keg Return – Some venues charge a hefty deposit that isn’t refunded if the keg isn’t returned on time. Plan a pick‑up schedule and keep the deposit receipt.
Most articles skim over these operational details, leaving readers with a half‑filled keg and a lot of wasted beer.
The Verdict: Which Forty Should You Choose?
If your priority is cost‑effectiveness and you need to serve a large crowd quickly, go for a standard stainless‑steel 40 L keg filled with a session lager. It’s cheap, easy to chill, and keeps the party flowing.
If you want to impress craft‑savvy guests, opt for a forty of a well‑reviewed American IPA or a Belgian Saison. The higher price per litre is justified by the flavor complexity and the novelty of serving a keg‑packed craft beer.
Bottom line: the best forty of beer is the one that matches your event’s vibe, budget, and logistics. Choose the right style, keep it cold, set the correct pressure, and you’ll have a crowd‑pleasing, waste‑free solution that outperforms dozens of individual bottles.
Where to Get Your Forty
Many local breweries now offer direct keg sales, and large distributors can ship a forty to your door. For a seamless experience, use a reputable supplier that guarantees a fresh brew date and provides a compatible tap system. Need help navigating the market? Check out our guide to buying and serving beer for more tips on handling kegs like a pro.
