Champagne Bubbles Show If A Glass Is Clean

According to a Bubble physicist named Helen Czerski says you can tell if a champagne glass is clean by the bubbles. She stated, "If you've got a champagne glass and it's got bubbles coming from everywhere around the inside of the glass, I hate to tell you this but the glass is dirty. Don't tell your host, it won't make you popular. So in a clean champagne glass, there is a rough bit at the bottom."