Here's The Significance Of The Markings At The Bottom Of Your Draft Beer Glass

Have you ever noticed an etched design at the bottom of your glass as you drain the last dregs of your draft beer? No, the etching isn't for decoration. It's not just a branding opportunity for the brewery, either — though many breweries use it as a place to display their logos. Those designs actually serve a practical purpose. "They're etchings meant to cause nucleation," Lane Fearing, co-founder of Roaring Table Brewing Co, told The Takeout. "Nucleation happens when dissolved CO₂ clings to imperfections like etchings, dirt, or soap residue and forms bubbles."

Remember the Mentos-and-Coke experiment from middle school? It's the same process at play, just with more drama. While Mentos may appear to be smooth, tiny irregularities on the surface of the candies trigger a carbon dioxide-powered geyser.

"In an etched glass, that's intentional. Everywhere else, it's usually bad news," said Fearing. Dirty glassware isn't just gross: When CO₂ clings to dirt or grime, the bubbles tend to get trapped on the side of the glass. Etchings on the bottom help direct the CO₂ upwards. "​​Etched glasses create a steady stream of bubbles, help sustain the head, release aromatic compounds, and gradually soften carbonation — making the beer more aromatic and smoother on the palate," explained Fearing. The one downside? Etched glass makes beer go flat faster, so it's not ideal for folks who like to nurse a pint.

You probably know that the shape of a wine glass can affect the experience, even if you don't necessarily know which glass to pair with rosé, and which to pair with Bordeaux. Glasses can have an impact on IPA's and stouts, too, even if the nuances aren't as mainstream — except maybe among craft beer fans, who are famously obsessive about their brews.

Both local breweries and national chains put much thought and consideration into their glassware. The Teku Glass, for example, which looks more like a wine glass than a standard pint, leaves beer snobs divided. And for its part, Applebee's designed the unique Brewtus glass to help keep beer cold.

Glassware doesn't necessarily make or break a beer; its impact on the drinking experience is subtle and tends to be most apparent in aroma, not flavor. But while it doesn't make much sense for a casual beer fan to clutter up their cupboards with glasses for every occasion, if you want to give your bottled beer a boost of straight-from-the-tap carbonation, an etched glass might be the way to go.