. . . courtesy of Adam Hart-Davies!
If you really want to find out how much you fart after a meal of beans, take a bath a few hours later, and take into the bath a small empty plastic bottle. Fill the bottle with water, hold it upside down, keeping the open end under the surface so that it stays full of water, and pull it up between your legs so that when you fart, the gases bubble up into the bottle. Can you beat 250 ml?
If you don’t want to stop eating beans, but find all this flatulence rather embarrassing, then just remember that you’re not alone—everyone does it. Edward de Vere, Earl of Oxford farted loudly as he bowed to Queen Elizabeth I, and was so ashamed that he travelled abroad for seven years. When he returned to her majesty's presence, however, the first thing she said was "My Lord, I had forgot the fart."
. . . hmmmm, now where did I put that empty pop bottle . . . .?