So the question has popped up on several occasions if you should time boiling when your food goes into the water or when the water returns to a boil. And really I think it is a different answer for what you are trying to achieve. If you are blanching a vegetable, you should start counting the minutes as soon as you plunge your vegetable into the boiling water. The goal is not to cook but to soften slightly while still being crisp and tender. If you start counting when the water returns to a boil, your food will be overcooked. For foods to be cooked all the way through, like pasta or potatoes you should start counting once the water returns to a boil. Of course, when something must be cooked completely it is safest to start checking early to prevent overcooking.