How to get that great “hoppy” beer taste without the exploding bottles

Enlarge / In dry hopping, hops are added during or after the fermentation stage of the brewing process. (credit: Natasha Breen/Getty Images)

Last month, the Quebec-based Le Castor brewing company recalled three different brands of its beer after numerous incidents of exploding bottles. The beer was re-fermenting in the bottle, and the resulting high pressures proved too much for the bottles to withstand.

This is hardly an isolated case. In 2014, a sour fruit beer called Swill was pulled from North American shelves after several bottles exploded. And a Manhattan barback is suing his former employer after a bottle of Corona exploded while he was placing it in an ice bucket (the incident left him permanently blinded in one eye). That wasn’t even the first time a Corona bottle had exploded at the bar. Google “exploding beer bottles” and you’ll get hundreds of results.

The culprit is probably the hops, according to Thomas Shellhammer, a food scientist at Oregon State University and co-author of a recent paper in the Journal of Agricultural and Food Chemistry—specifically, Shellhammer points to the growing popularity of a brewing process known as “dry hopping.” Far from being the chemically inert ingredient brewers have long assumed, hops contain starch enzymes that, under certain conditions, can boost their activity to such a great extent that excessive re-fermentation occurs (“hop-creep”).