What type of thermometer is commonly used in coffee preparation?

The frothing thermometer is specifically designed for use in coffee preparation, particularly for monitoring the temperature of milk during the frothing process. This thermometer typically has a clip that allows it to be attached to the side of a steaming pitcher, making it easy to read the temperature as milk is heated. It is essential for achieving the optimal temperature for frothing, which is crucial in creating a velvety microfoam for lattes and cappuccinos.

In contrast, a liquid thermometer is generally more suited for other applications and might not have the same design features that facilitate use during coffee preparation. An infrared thermometer, while useful for taking the surface temperature of various items without contact, may not be as reliable for precise temperature readings needed in espresso or milk frothing. A glass thermometer could serve similar purposes as the frothing thermometer, but it lacks the specificity and convenience that the frothing thermometer offers for baristas.