If your beer tastes or smells like it was filtered through a skunk’s butt, it is probably due to the beer being “skunked” or named Heineken or Rolling Rock (zing!). Almost nothing makes for a worse beer experience than getting a mouthful of rancid beer water when you were hoping for hoppy deliciousness. But why does this happen? WHY!
Let’s get this out of the way first: temp changes don’t skunk beer. It’s not recommended to subject a beer to extreme temperature shifts, but you aren’t going to taste the back end of Pepe Le Pew because of it. Skunking comes from beer that is exposed to sun or fluorescent light, which is why it’s technically referred to as “lightstruck.” A chemical reaction causes the beer to produce methyl mercaptan, also found in what skunk’s spray, hence the similar odor.