A cold beer poured into a glass at the end of a long day is one of life's simple pleasures. But have you ever noticed bubbles sticking to the side of the glass after you've poured your beer? While it may seem trivial, it's an indicator that your beer glass might not be as clean as you think.

In a spotlessly clean beer glass, the bubbles should rise steadily from the bottom to the top, creating that classic frothy head people love so much. When bubbles adhere to the side of a glass, it's often because of residues left behind — whether from detergent, grease, or even just an imperfect rinse.

These residues create nucleation sites: small imperfections where CO2 can come out of a solution and form bubbles. Essentially, the bubbles attach to these sites because they offer an easier place for the gas to escape compared to the smoother surfaces of the glass. This phenomenon not only affects the visual appeal but can also change the aroma and overall experience of your beer.

To ensure your beer glasses are clean and prevent nucleation sites on the walls of the glasses, be sure to clean them thoroughly. While it might seem old-fashioned, hand washing your beer glasses can be the best way to ensure they're properly cleaned. This allows you to feel any potential residues and give problem areas extra attention. Detergents can leave behind residues that not only attract the bubbles but can also affect the taste of your beer. So if you do use soap, make sure to rinse the glass thoroughly.

After washing, place the beer glass upside down on a clean dish rack. Letting it air dry rather than using a towel can prevent lint or other residues from being transferred to the glass. Finally, before pouring your beer, inspect the glass in good lighting. Look for any water spots, smudges, or lip marks. Rinsing the glass with water will also help remove any foreign particles like dust before pouring the beer. You can even sprinkle a little salt into the glass to see if it sticks, which indicates residual moisture on the glass.

So, the next time you pour yourself a cold one, let those rising bubbles be a testament to a perfectly clean glass — or a red flag to a lesser beer experience.