What Is the Function of a Water Bath?

Typically used during an incubation in microbiological laboratory work, a water bath keeps water at a consistent temperature. A water bath can also be used to enable a chemical reaction to occur once the water reaches a certain temperature.

A water bath should be filled with distilled water and checked regularly to make sure the temperature remains correct. It is generally recommended to keep a thermometer in the water to record the temperature.

All water baths have a digital interface or dial that allows users to control the temperature. Usually, an indicator light turns on to indicate that the water bath is working. Once the correct temperature is reached, the water bath turns on and off to maintain a consistent temperature. Most, but not all, water baths have a secondary safety setting that prevents the water from heating to a higher temperature. When this temperature is reached, an indicator light turns on.

Some water baths, known as shaking water baths, provide additional controls that allow users to control the speed and frequency of the movements. Used primarily to mix two substances together, a shaking water bath can be used in lieu of a standard water bath by turning the shaking mechanism off.

A water bath goes up to 100 degrees Celsius. For higher temperatures, an oil bath should be used instead.