A manual Frother is typically designed as a hand pump utensil consisting of a container with a fine mesh screen on one end and a pump handle attached to a plunger on the other. Several types of manual Frothers are manufactured for Frothing. Some are made as self-contained, single stainless-steel or plastic chambers that are immersed into a glass of milk for Frothing. Others are made as canister frothers with glass containers that hold the contents to be Frothed and a pump built into the container. Those that are built as self-contained utensils have a pump handle plunger that fits into the stainless container. As the pump is pulled upward it draws air and liquid into the stainless steel chamber of the Frother. The pump plunger is then moved in a downward direction to force out the liquid and air through the fine screen so the air and liquid mixture becomes aggitated to create a foam filled with tiny bubbles as it exits the Frother. Canister Frothers work in the same manner of pumping the contents to draw air into the milk in order to froth it. The Canister Frother works best when filled with only a third of the container filled with milk to allow for the expansion of the Froth.
There are several common types of battery operated Frothers, some with small wire whisks or others with small propeller blades. Each is effective for aggitating the liquid to create a thick foamy froth or for simply blending easily blended solutions. As liquids are frothed with an propeller Frother, this type of utensil may be slightly more damaging than a wire whisk to some of the surfaces of containers holding liquids to be frothed. However, the propeller Frother may be able to blend and foam a wider variety of liquids or ingredients without being over-worked as may occur with a fine wire whisk type of Frother.
Electrical Frothers are built as an accessory to an appliance, such as a coffeemaker or as a self-standing frother with a blender-like apparatus built within to whisk the milk into foam. The Frother built on coffeemakers uses heated water from a seperate holding tank to provide steam that is forced out the Frothing stem as the water heats and agitates the liquid being foamed. Many cappucino and expresso coffeemakers are equipped with built-in Frothers. The blender-like Frothers are made to hold 2 to 4 cups of liquid to be Frothed at one time in order to produce larger volumes of foam. With an appearance similar to a food processor, this type of Frother will heat the milk and then quickly agitate it into foam. This type of Frother is often used in commercial kitchens or in homes where the Frother is used several times a day for more than one cup of Froth.
As a general rule, heavier liquids such as cream or whole milk will provide a thicker foam than fat-free or low-fat milks. However, the ligher liquids such as low-fat milk can be foamed if the reduced-fat alternative is desired and this type of milk will provide a very nice Froth. When steam is used to create a Froth, the result is a heavier textured mixture, thicker in consistency that may be slightly harder to digest for some. Thus, lighter Froths which are typcially made without steam can also provide a nice alternative for those preferring a lighter texture. The best Froth is made when cold milk temperatures range from 32ºF to 40ºF (0ºC to 4ºC) or warm milk temperatures reach a temperature of 140ºF (60ºC).