Some of the Trendiest Craft Beers Are Exploding. Huh?!

When brewers add fruit purees or extracts just before canning, they're feeding active yeast a ticking time bomb.

- By Claire Porter

We all know the sound: tschhhk followed by a fizzy hiss. It's the sound of cracking open a crisp, cold beer. But there's another, much less inviting sound you might have been unlucky enough to hear the loud and definitive pop of an exploding beer can. This explosive phenomenon gained notoriety in 2018 when cans of craft beer, often made with fruit, were spontaneously erupting. In February 2021, one US craft operation voluntarily recalled one of its sour ales for the same reason. The good news is breweries go to great lengths to ensure that these bad batches are the exception, not the norm.

Whether it's beer, seltzer, or soda, as carbonated beverages warm up - from cold refrigeration to room temperature and beyond - the carbon dioxide becomes less soluble, leaving the liquid and moving to the air space at the top of the can. Aluminium cans are built to withstand this normally slight increase in pressure, but at excessive carbonation levels, they're likely to burst at the seams.

This becomes a problem with beers that are prone to refermentation, a process in which yeast and microbes continue to process sugars, expelling additional carbon dioxide. It's most common with increasingly popular fruited or flavoured beers because they have both active yeast and fermentable sugars.