You’re drinking a can of Guinness. As you near the bottom, something rattles around inside the can. You look inside and see, to your surprise, what looks like a ping pong ball. Was it a factory error?

Add Yahoo as a preferred source to see more of our stories on Google. Why there's a white plastic ball in Guinness beer cans The Guinness widget is a tiny, plastic ball inside beer cans. During ...

Guinness lovers, ever wondered what gives your favourite pint that iconic white creamy head? Well, there's a secret inedible ingredient that's responsible for that luscious froth. Sure, cracking open ...