What Is Lactose and Why Is It in My Beer?

April 18, 2019

By Miles Liebtag, April 18, 2019

Without sugar, there is no beer. Yeast metabolize sugar to produce ethanol. In other words, your 10% ABV imperial stout owes its booziness, in part, to sugar. The sugar we’re most familiar with is sucrose, AKA common or table sugar, usually derived from sugar cane. Lactose, a sugar which occurs naturally in the milk of all mammals, has only about 15% the perceived sweetness of sucrose, but it can also add richness to food products—including beer. Today, craft brewers are turning this once-uncommon ingredient into a major component of popular styles.

The origin of the milk stout can be traced back to early 20th century England, an outgrowth of the increased popularity of dark ales like porter, and later strong (or “stout”) porters. Marketed as a fortifying drink for convalescents (and sometimes even children), “milk,” “sweet,” or “cream” stouts were generally beers with low amounts of alcohol but high amounts of residual sugar. Residual sugars are those left in a beer after the yeast has completed its fermentation. Because lactose is unfermentable by brewer’s yeast, lactose added to a beer makes the final product sweeter, fuller, and creamier.

For more than a century, lactose found its way into very few beer styles beyond sweet stouts. The popularity of this small style family waned in its native England as the 20th century wore on, and most drinkers today are probably more familiar with the iconic American craft brand Left Hand Milk Stout than they are with classic UK-born examples like Mackeson’s Triple Stout. Left Hand Milk Stout is arguably the best known sweet stout brand today, and its associated Milk Stout Nitro brand—infused with nitrogen and served on draught through a stout faucet to accentuate its natural creamy richness—has become an American classic since its introduction in 2011.

The resulting drink is often something that is only vaguely recognizable as a beer, let alone an IPA.”

A lot has changed since then. Today, craft beer drinkers are almost more likely to encounter lactose in an IPA than in a traditional milk stout. As the brewing industry continues to find increasingly inventive (some might say desperate) ways to reimagine the best-selling craft beer style in history, lactose has been pressed into service. The once outré “milkshake IPA,” as the name hints, employs lactose to fill out, sweeten up and flavor beers that bear no real resemblance to India Pale Ale as it’s been traditionally understood. Not that there’s anything wrong with breaking away from tradition—American craft brewing wouldn’t exist otherwise. 

Milkshake IPAs are generally regarded as a symptom of the New England IPA craze, an iteration of IPA where the rough edges have been sanded down. The NEIPA is low in bitterness, with a very soft and “pillowy” mouthfeel, often derived from the use of copious amounts of unmalted oats, which add a silky and full texture to the finished beer. The milkshake IPA goes further—usually with a heavy dose of lactose for creaminess—it is also sometimes accentuated by flour or pectin (a gelling agent used in making jam), then flavored with fruit puree or another dessert-like ingredient. Henok Fentie of Omnipollo created the first milkshake IPA in collaboration with Tired Hands Brewing Company in 2015, and the beer included oats, lactose, and pectin, as well as strawberries and vanilla beans.

A good milkshake IPA, according to Fentie, “should be seamless and not forced. And [the lactose] should be paired with some other element to give it balance.” Hops here are employed largely for their fruity characteristics and added very late in the brewing process (or as massive dry hop additions) to maximize sweet fruit aromas and flavors without adding bitterness. Lactose is usually added as a powder late in the brewing process, simply stirred in and dissolved. The resulting drink is often something that is only vaguely recognizable as a beer, let alone an IPA. These are thick, sweet, dessert-like beers.

I’m lactose intolerant myself, but can easily drink a couple of these beers. Two glasses of milk would be a different story.”

“Dessert-like” may actually belie the nutritional truth here: these beers are dessert. Some of today’s most popular beer styles—high gravity hazies, decadent pastry stouts and, yes, milkshake IPAs—pack a wallop in terms of calorie, carbohydrate, and sugar content. Consider that a typical homebrew milkshake IPA recipe calls for one pound of lactose sugar. Since none of that sugar will ferment, a resulting 12-oz. serving would contain around eight grams of milk sugar. Not bad compared to a can of Coke, which tops out at almost 40 grams of sucrose, but soda has potentially half the calories of a 12 oz milkshake IPA. Once you account for the added sugar, fruit and flavorings, and precious, precious ethanol, your average milkshake IPA (or flavored stout) can easily clock in at 250 to 300 calories per 12-oz. serving. Of course, you’re drinking a pint can—right?

Getting a handle on the nutritional content of lactose-heavy beers can be tricky. “I think if an educated customer is drinking a beer made with lactose they accept a higher level of residual sugar,” says Ryan Morrow, brewmaster at Collective Arts Brewing in Ontario. Fentie of Omnipollo says they endeavor to a light touch with milk sugar: “We try to stay low on the lactose and use a less is more principle… [but] our thesis is that lactose sugar in beer comes across as less offensive. I’m lactose intolerant myself, but can easily drink a couple of these beers. Two glasses of milk would be a different story.” And there’s no real clear indication as to how milk sugar content in beer might affect the lactose intolerant generally, Fentie’s strong stomach notwithstanding. “You really don’t want to taste the lactose,” Fentie says. “It's more a feeling we are after. If you can taste the lactose, we have failed.”

Some drinkers, however, just don’t want animal products anywhere near their beer. For instance, isinglass, a traditional clarifying agent historically made of collagen derived from fish bladders, has been enough to turn off some drinkers. And although isinglass is no longer in wide general use, mammal-derived lactose sugar can still be a red flag for some. "I find it amusing how often lactose is used these days, despite an ever-increasing customer base who doesn't want to drink beer with a milk byproduct in it,” says Chris Davison, head brewer at Wolf’s Ridge Brewing in Columbus, Ohio. In today’s incredibly competitive beer market, alienating any potential customer is a risky proposition. “I won't let those concerns keep me from using lactose where I feel the need,” Davison says. “But I hear the question often enough to take note that I don't want half my draft list to contain lactose either.”

When asked if Davison has an idea of how using lactose otherwise affects the nutritional content of their beers, he laughs, “Not really."

Illustration by Adam Waito

ZX Ventures, a division within AB InBev, is an investor in October
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