Acidulated water is a chemical solution made by mixing an acid with water. It has many cooking applications, most of which focus on retaining color. It is very easy to make acidulated water at home, by adding an acid such as vinegar, lime juice, lemon juice, or white wine to water and shaking it to distribute the acid. The resulting acidulated water should be used relatively quickly. Most cooks mix up a fresh batch for each intended use.

Of the most useful applications for acidulated water is as a soak for fruits and vegetables to prevent browning. Fruits such as apples, avocados, and pears can be dipped in acidulated water to slow the browning process. The same can be done for many vegetables. The acidulated water will not completely stop the browning, but will greatly slow it, keeping the vegetables looking fresh and crisp if they are to be eaten raw. In addition, the faintly tart flavor of the water is pleasing to the palate.

When acidulated water prevents browning, it does so in two ways. Coating a fruit or vegetable in water reduces the amount of oxygen that the cut regions are exposed to. Since browning is caused by oxidation, the rate of browning will be slowed. The lower pH on the surface of the food created by the introduced acid will also slow browning. When using an acidulated water soak, the food should not be saturated, or it will taste soggy. It should also be patted dry before use.

There are also uses for acidulated water in cooking. Vegetables which are cooked in acidulated water will retain their color, instead of graying or browning out. This can make cooked vegetables look much more appetizing, and the faint hint of acid will also have an impact on the flavor. Acidulated water is also used in poaching, as the lower pH of the water will help the proteins in ingredients like eggs and fish to cook thoroughly.

Some people also like to drink acidulated water. The neutral flavor of ordinary water is unappealing to some people, while water with a hint of acid tastes more crisp and refreshing. If people have difficulty drinking their daily recommendation of water, making up a bottle of acidulated water may be a good idea. Lemon and lime are the best additions to acidulated water which is intended for drinking, and a sprig of mint can also make the flavor more appetizing.