Salt raises the boiling point of water slightly, but the effect in a kitchen pot is tiny.

The longer version

Dissolving any solute in water interferes with the ability of water molecules to escape as vapor, so a slightly higher temperature is needed before bubbles can form and persist. This is a colligative property, meaning it depends on how many dissolved particles are present rather than on what they are.

In practice, the amount of salt used for seasoning is far too small to produce a noticeable change in cooking time; the shift is a fraction of a degree. What salt clearly does change is flavor, since it suppresses bitterness and sharpens other tastes. Dissolved material in syrups and heavy brines does produce measurable shifts, because the concentration there is far higher.

Where this entry sits

Everyday ingredients turn out to be full of quiet chemistry and long history. This collection gathers short, plain explanations of how bread rises, why onions sting, where common spices originate, and how coffee, tea, and chocolate reached the modern kitchen. The full list sits on the Food and Drink page, where every entry is listed in order.