When we weren’t paying attention, a pot or two (or fifty) boiled over onto the stove. By placing a wooden spoon over the pot in question, you can avoid this common cooking blunder.
This works for a variety of reasons. First, when unstable bubbles from a boiling pot collide with a wooden spoon made of a water-resistant material, the bubbles pop and the water level returns to normal.
Second, because the temperature of the spoon is less than 212 degrees Fahrenheit, the steam-filled bubbles re-condense into water and weigh down the other bubbles.