Most mass-market beers—like those made by Anheuser-Busch, Coors, and Miller—have twist-off caps you can open with your hands, but craft brews tend to have pry-offs that require a bottle opener. Pry-off capping equipment is slightly less expensive than twist-off equipment, which is a factor for some small breweries. But many craft brewers choose pry-off caps not for the savings but because they believe those caps provide a better seal against oxygen.

“Oxygen is one of beer’s greatest enemies; it causes beer to become stale,” says Garrett Oliver, brewmaster at Brooklyn Brewery, which uses pry-offs.

It’s difficult to say, however, how much of a safeguard pry-off caps provide. Steve Harrison, vice president of Sierra Nevada Brewing Company, says that his R&D department has studied the oxygen barriers on twist-off and pry-off caps for 12 years. In those tests, they found a slight difference, but not enough to have a significant effect on the beer. (Sierra did, however, recently switch from twist-offs to pry-offs. The reason was that the brewery began using a new bottle-cap lining material that provides a much better oxygen barrier but is too stiff to work with twist-offs.)

Maybe people just think pry-offs are more legit. The Brewers Association, a trade organization for craft brewers, estimates that 80 to 85 percent of its members use pry-off caps on their beer bottles. This reinforces the idea among craft-beer drinkers that only good beers use pry-offs. Admits Oliver, “Twist-offs have a cheaper image.”