What's That Little Ball Rattling Around Inside Guinness Cans? - Chowhound

YnetteT/Shutterstock It's hard to beat the experience of having a bartender pour you a draught glass full of Guinness fresh from the tap, but the stout beer is also sold in bottles and cans. If you've ever purchased cans of Guinness, you've heard the rattling sound that an empty one makes. You may have wondered what's making all that racket, or you may be one of those people who's given into curiosity and sliced…