What is a rolling boil?

A rolling boil is the term used to describe a vigorous and continuous boiling of a liquid, typically water. It is characterized by large bubbles breaking the surface and churning the liquid.

When a liquid reaches a rolling boil, it is heated to its highest possible temperature under normal atmospheric pressure, which is typically 212°F (100°C) for water. This level of heat causes the water to evaporate quickly, creating the rapid bubbling and churning motion.

A rolling boil is often used in cooking, particularly when boiling pasta, vegetables, or making soups and stews. It helps to cook food quickly and evenly, preventing overcooking or undercooking.

It is important to note that a rolling boil may be too intense for some delicate foods, such as eggs or fish, as the rapid movement of the water can break them apart. In these cases, a gentle simmer (small bubbles breaking the surface) may be more appropriate.