There are the ways to celebrate. The first is obvious, the second is to read this article, the third is to purchase our brand-new beer trivia book Uncle John’s Beer-Topia.

Why do some beers, particularly light lagers in packaged in green bottles, smell bad and taste just a little bit weird?

Do you know what we mean? A less informed individual might say that a Heineken, Grolsch, or Stella Artois beer gives off a weird odor and even tastes a little “skunked.” Both of these are what happen to draught (from the tap) beers in glasses left out on a table for a few hours too many. But Heinken, Grolsch, and Stella Artois are “premium” import beers—and priced accordingly—so why does it seem like they’re rotting before you’ve even had a chance to enjoy them?

Don’t worry—your Heinie isn’t rotting (ha!). Heineken and other pale European-style lagers are very old beers (Heineken began in 1864 in Amsterdam) with very particular and very carefully calibrated flavor profiles. The skunkiness is part of what makes it and other beers taste special (and similar to one another). The taste of “skunked” bottle beer is the result of being light struck. It’s a sour, bitter flavor is chemically created to give the beer an extra dimension. It occurs from exposure to light. Being bottled in a fairly transparent green bottle imparts enough light exposure to slightly change the chemical makeup of the beer—something that doesn’t happen in thick, light-obscuring brown beer bottles. Prolonged exposure to light (and air) is what makes a tap beer in a glass tastes weird.

As for the smell, well, that’s from the hops, a pungent plant that helps give beer its beer-y taste…and it’s related to marijuana.