Bring to a boil

"Bring to a boil" means heat a liquid until it boils: big bubbles rise from the bottom and break all over the surface. At sea level, water boils at 100°C (212°F). It is often a first step before you add pasta, lower the heat to a simmer, or cook something for a set time. British recipes say "bring to the boil".

How to do it

1. Use a pan big enough that the liquid fills it no more than three quarters full.
2. Put a lid on. Covered water boils faster because less heat escapes.
3. Set the heat to high.
4. Watch it as it gets close, especially with milk, sauces and starchy liquids, which boil over easily.
5. When it boils, follow the next step in the recipe, which is often to add food or turn the heat down.

How to tell it is done

Steam pours off the surface and large bubbles break across the whole pan, not only at the edges. Small bubbles on the bottom and sides that do not rise are not a boil yet. If stirring does not stop the bubbling, you have a rolling boil.

Common mistakes

• Walking away from milk or cream. They foam up and boil over within seconds. Stay with the pan and stir.
• Adding food to water that has not reached a full boil. Pasta turns gummy and vegetables take longer and lose color.
• Boiling a sauce or stew hard when the recipe says to bring it to a boil and then simmer. A hard boil toughens meat and can split sauces.
• Using a pan that is too small. It boils over when you add food.

In recipes

"Bring to a boil, then reduce to a simmer" is very common for soups, stews, grains and stocks. The boil makes sure everything is hot, and the simmer cooks it gently. "Bring back to a boil" means wait for the liquid to boil again after you add cold food. "Bring just to a boil" means stop as soon as the first bubbles break the surface. At high altitude water boils at a lower temperature, so food takes longer to cook. For a pot of pasta, see salted pasta water.