A lack of foam is less of an issue for mainstream American lagers, which have few nose-worthy aromas. But many modern craft beers emphasize pungent scents and taste. The right combination of ingredients, alcohol level, equipment and serving style can produce an impressive, fragrant head.

Glassware has long been a hurdle to serving beer with foam. The prime culprit is the shaker pint, the default glass at many bars and breweries — a sturdy, affordable 16-ounce vessel designed for mixing cocktails. “I call shaker pints the cockroaches of beer glasses,” said Randy Mosher, the author of “Tasting Beer.”

The problem with shaker pints is twofold: Their straight-walled, wide-mouthed shape doesn’t concentrate the foam, and they have enough space for only a pint of liquid — 16 ounces, filled to the top.

Some beer drinkers perceive foam as stealing a few precious ounces of beer. Bushwick Country Club, a bar in Williamsburg, Brooklyn, has one particularly foam-averse regular. “If there’s more than an eighth-inch of foam, he complains,” said John Roberts, the owner.

This confusion stems in part from America’s Wild West, no-rules approach to serving size. The federal government doesn’t mandate that a pint glass contain a minimum volume, and some may hold only 14 ounces of liquid. In Britain, regulations require that a pint glass hold 20 imperial fluid ounces, equivalent to about 19.2 fluid ounces in the United States.

“You’d be amazed by how many glasses are ripping you off,” said Ms. Carter, of Bierstadt Lagerhaus. “Bars are saying you’re getting 16 ounces of beer, and you’re not.”

Bierstadt is transparent about its pouring sizes, which makes it easier to educate customers about the merits of foam. Since opening in 2016, the brewery has served beer only in its own style-specific glasses, and requires that other bars serving its beers do the same. The glasses have clear markings that denote a specific metric liquid measure, such as the half-liter for its golden helles, a German-style lager served in a large mug.