A potato ricer is used to process food by forcing it through small holes which are often not much larger than the width of a grain of rice (hence the name). This action results in a purée. Mashed potatoes are a food commonly made using this utensil. In technical terms, it works by a process of extrusion. A potato ricer can also be used to squeeze excess water from sliced or grated potatoes. This is useful to make crispy chips, hash browns and rösti.
At least three types exist. The simplest variety is little more than a grid on a handle. Food is processed against a flat surface or inside a container. Slightly more elaborate models resemble a very large garlic press. A rotary type, called a food mill, also exists and here the food is driven towards the grid by a large screw, similar to a meat grinder/mincing machine but without the rotary blade.
The potato masher consists of an upright or sideways handle connected to a mashing head. The head is most often a large-gauge wire in a rounded zig-zag shape, or a plate with holes or slits.
With a potato masher you have the option to make a rougher mash, whereas with a potato ricer, you will only ever get a purée.