Until recently, “craft lager” might have sounded like an oxymoron. After all, lager — you know, like Budweiser, Coors and Corona — was the very thing that the craft beer revolution defined itself against. The industrial lagers were flavorless, wan and dilute; craft beer, by contrast, would be rich, complex and delicious.

But over time, that desire for intense flavor turned beer drinking, once a leisure activity, into an endurance sport. Aggressively hoppy IPAs now dominate tap handles at Bay Area beer bars. Everything is aged in bourbon barrels, infected with brettanomyces or brewed with sour cherries or pineapple or lactose. It’s no longer uncommon to see alcohol levels creep into the double digits.

These craft beers are much more flavorful than Budweiser and Coors. But is there such a thing as too much flavor?

“They’re palate wreckers,” says Rob Lightner, co-founder of East Brother Beer Co. in Richmond, of the current craft-beer landscape.

His brewery is part of a growing movement in California to provide an antidote: craft lager. Open since 2017, East Brother is the rare craft brewery that actually specializes in lager (which includes subcategories like pilsner). That means it doesn’t often get to participate in the craft-beer hype machine. “We’ve watched the glitter beers, the brut IPAs, the hazy IPAs all take off,” Lightner says.

But they’ve stuck to their guns, and it’s working — not just for East Brother, whose lagers “outperform” in their taproom, Lightner says — but for craft beer as a whole.

Lager remains the most popular beer style in the U.S., but the macro-lagers — the Coors and Buds — are on a downward trajectory, shrinking 2% by volume in 2018, according to industry analyst IWSR. Within craft, however, lager is a growth segment, says Bart Watson, chief economist for the Brewers Association.

“Lager is a way for craft breweries to reach this light, refreshing portion of the beer market,” Watson continues. “Craft has reached a certain market share where it has to reach out to different consumers — so they’re moving into the biggest space in the U.S. beer market, which is still light lager.”

A lager’s greatness comes from subtle complexity. It should be bright, crisp and clean, finishing dry. Some Bay Area craft lagers are emphatically hoppy (Russian River Brewing’s STS Pils comes to mind), while others are less so (think of North Coast Brewing’s Scrimshaw Pilsner). Recently, we’ve seen a spate of specifically light lagers, even from hazy IPA havens like Fieldwork Brewing and Humble Sea Brewing.

But the major defining trait of the current wave of California craft lagers is maltiness, which can come across as a subtly grainy or biscuity flavor. That maltiness is also what differentiates craft from industrial lager. Craft versions like Local Brewing’s SF Lager and East Brother’s Bo Pils are brewed entirely from malted barley. Meanwhile, the macro-lagers rely heavily on adjuncts, like corn and rice, which are cheaper. (Bud Lite has been flaunting its use of adjuncts in a recent ad campaign. To promote the fact that it doesn’t use corn syrup, it spells out its ingredients: hops, barley, water and rice.)

And lager is a broader category than many drinkers realize. The style invites plenty of experimentation: San Francisco’s Local Brewing Co. produces a red lager, a black lager, a dry-hopped Mexican lager and, as a Beer Week special, a whiskey- and oak-influenced lager. East Brother has a seasonal lager series, which includes maibock, festbier and even Baltic porter (which, yes, is also a subcategory). Of course, pilsner may be the breakout star; everyone from Lagunitas to Firestone Walker is making one now.

Still, lager isn’t sexy. It doesn’t drive cool Instagram posts. It garners mediocre scores on the beer-rating site Untappd. “No one in my circle is ever sitting around and saying, ‘Hey, have you had this lager?’” says Regan Long, founder and brewmaster of Local Brewing Co.

For a brewery, in fact, lager can feel like a thankless labor. It’s more difficult and more time-consuming to produce than many other beer styles. Because lagers must be fermented at colder temperatures, they take considerably longer than ales. “The reality is you can turn a standard West Coast IPA in two weeks, but a lager is taking four to six weeks,” says Long. “They take up a lot of space. For a lot of breweries, they just don’t make a lot of sense.”

Unlike an IPA, whose assertive hops might be able to mask other flavors, lagers are unforgiving. “If there’s an off flavor, if you rushed things, there’s nothing to hide behind,” says East Brother head brewer Paul Liszewski, whose license plate reads “LAGER.” He likens it to the difference between making a barbecue sauce — just throw together ketchup, chile powder, Worcestershire, brown sugar — and a beurre blanc sauce, which has fewer ingredients but relies on precise technique.

Craft lager may look like a new trend, but Watson, the Brewers Association economist, sees lager as having been in craft beer’s DNA from its inception; think Sam Adams Boston Lager. “For much of its history, craft brewing hasn’t been avoiding lagers so much as it’s been trying to go in an opposite direction of American lager and light lager,” he says.

Then, as now, the difference, says Watson, “is just that craft has been trying to add a little more flavor.”

Esther Mobley is The San Francisco Chronicle’s wine critic. Email: emobley@sfchronicle.com Twitter: @Esther_mobley Instagram: @esthermob