What the 40’s of Beer Actually Are
Right now you’re standing in a dimly lit tasting room, a glass of amber liquid trembling in your hand, and the bartender whispers, “This is one of the 40’s of beer.” The 40’s of beer are not a decade or a style family—they are beers that push the alcohol content up to, and often beyond, 40% ABV, delivering a potency usually reserved for spirits. In other words, they are ultra‑high‑proof brews that sit at the intersection of craft beer ingenuity and distillery science.
Understanding this niche category means recognizing that these beers are deliberately engineered to achieve a level of alcohol that most traditional ales and lagers never approach. They are made with specialized brewing techniques, massive malt bills, and often a secondary fermentation or fortification step. The result is a drink that can taste like a rich dessert, a barrel‑aged whiskey, or a complex liqueur, depending on the recipe.
How Brewers Reach the 40% Mark
Creating a beer that climbs past 30% ABV already strains the limits of yeast metabolism. To breach the 40% threshold, brewers employ a combination of methods:
Massive malt extracts and adjuncts. A typical 5% ABV ale uses roughly 1.5 kg of grain per 10 L. For a 40% brew, that figure can balloon to 10 kg or more, providing the fermentable sugars needed to sustain high alcohol production.
Yeast selection and adaptation. Standard ale yeasts die off long before reaching 15% ABV. Brewers turn to high‑gravity tolerant strains such as Belgian Trappist “Saison” yeasts, turbo yeast blends, or even specialized distiller’s yeast that can survive and keep fermenting in the 20‑30% range. Some recipes include a step‑up feeding regime, adding more sugars mid‑fermentation to keep the yeast alive.
Fortification. After primary fermentation, many 40’s use a spirit‑like addition—often a neutral grain spirit or brandy—to bump the ABV up without over‑stressing the yeast. This technique mirrors the traditional fortification of port or sherry.
Distillation‑style techniques. A handful of experimental breweries actually distill a portion of the fermented wort and blend it back, creating a hybrid that’s technically a beer‑spirit mash‑up.
Signature Styles Within the 40’s Category
While the overarching definition is the ABV, the flavor profiles vary dramatically. Here are the most common sub‑styles you’ll encounter:
Barrel‑aged Imperial Stouts. These often start as a 12‑15% ABV stout, then undergo a second fermentation in heavily charred oak barrels, sometimes with added maple syrup or coffee beans. The barrel imparts tannins, vanillin, and a smoky edge that balances the high alcohol.
Belgian Quadrupel‑style “Black Gold”. Inspired by the classic Belgian quadrupel, these versions push the malt bill and use a blend of yeast strains to achieve 30‑40% ABV, delivering notes of dried fruit, dark chocolate, and candied ginger.
Spirit‑infused Liqueur Ales. Think of a beer that behaves like a Baileys or Amarula. Brewers finish the brew with a splash of rum, whiskey, or brandy, then age it to allow the flavors to meld, resulting in a silky, dessert‑like experience.
High‑Proof Wheat & Saison hybrids. Some experimental brewers use wheat malt and a dry‑hop regimen, then fortify with neutral spirits, creating a surprisingly refreshing high‑proof session drink.
What to Look for When Buying a 40’s Beer
Because these brews are rare and often produced in limited batches, you need to be a savvy shopper. First, check the label for the exact ABV—some producers will list a range (e.g., 38‑42%). Next, examine the ingredient list: a long grain bill with specialty malts, a clear yeast strain note, and any fortification mentions are good signs of authenticity.
Packaging can also be a clue. Many 40’s are sold in sealed, heavy‑glass bottles or small kegs to protect the volatile aromatics. Look for bottles with a cork or a swing‑top closure, which indicates the brewer expects the beer to age and develop.
Finally, consider the provenance. Established craft breweries with a reputation for experimental high‑gravity work—such as BrewDog, Mikkeller, or The Bruery—are safer bets than obscure micro‑brands that might be chasing hype.
Common Mistakes People Make With 40’s of Beer
Most articles on high‑proof beers get two things wrong: they assume the flavor is always “boozy” and they suggest treating these beers like ordinary lagers. In reality, a well‑crafted 40’s can be nuanced, and they demand a different approach.
Mistake #1: Chilling them too cold. Lowering the temperature below 10 °C can mute the complex aromatics and make the alcohol taste harsh. Serve them slightly warmer—around 15‑18 °C—to let the flavors open up.
Mistake #2: Drinking them quickly. Because of the high alcohol content, sipping is essential. A 40’s is more akin to a fine whiskey; you want to let it linger on the palate, notice the evolution of flavors, and then decide if a palate cleanser is needed.
Mistake #3: Pairing them with the wrong food. Heavy, greasy dishes will clash with the intensity. Instead, pair with rich desserts (dark chocolate, crème brûlée), strong cheeses (blue, aged cheddar), or even a charcuterie board featuring cured meats.
Mistake #4: Ignoring storage requirements. Many 40’s improve with age, but they’re also susceptible to oxidation. Keep them upright, away from direct light, and consume within a year of bottling unless the label explicitly states a longer aging window.
Verdict: Which 40’s of Beer Deserves a Spot in Your Glass?
If you prioritize flavor depth and a drinking experience that feels ceremonial, go for a barrel‑aged Imperial Stout from a reputable brewery. The combination of high ABV, oak influence, and dark malt creates a layered profile that justifies the price and the effort.
If your priority is versatility—something you can enjoy as a nightcap or a special toast—a spirit‑infused Liqueur Ale is the better choice. Its smoother mouthfeel and dessert‑like sweetness make it more approachable for newcomers to the 40’s category.
Regardless of the style you select, remember that these beers are a celebration of brewing ambition. Treat them with the respect they deserve, and they’ll reward you with a sip that blurs the line between beer and spirit.
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