Whether you've grown them yourself or the taters come from a box, virtually every cook puts his own spin on classic mashed potatoes. Like many culinary tricks, however, the idea of soaking potatoes before including them in your favorite mashed recipe remains divisive; some swear by the method while others claim there are better ways. Experimenting with your own recipe is the most reliable way to formulate an opinion on the subject, but before you start tinkering, it helps to be informed.
In Support of Soaking
Potatoes naturally contain a starch known as amylose. If you whip up your mashed potatoes without removing some of this starch, you end up with a pasty, gummy dish. Soaking potatoes in water overnight removes some amylose, but for the trick to work, you must cut the spuds into roughly 1-inch pieces, which exposes an optimum amount of surface area. For safety, always soak the potatoes in the refrigerator and limit the soaking time to overnight, at maximum -- although just a few hours does the trick.
Making an Argument
Soaking is only one way to rid potatoes of a little sticky amylose. For an arguably quicker method, wash sliced potatoes after parboiling or steaming them but before you mash them by running them under cool water for a few seconds. This washing doesn't replace washing the potato skins, as it -- like soaking overnight -- targets the starchy insides of the spuds. For extra insurance, following both methods doesn't hurt. Try soaking the potatoes overnight, cleaning, slicing and parboiling the tots, then holding them under cool running water for a few seconds before cooking them completely.
A Taste for Nutrition
Apart from the effects soaking and rinsing have on the texture of mashed potatoes, these methods can affect nutritional content. Soaking can sap potatoes of nutrients. To retain these nutrients and up the flavor of your mash, parboil the potatoes in stock rather than soaking them. For a more subtly sweet flavor, parboil the potatoes in milk. Regardless of your prep methods, leave the skin on while boiling or parboiling to retain as many nutrients as possible. If you go with one of these methods, remember to rinse the sliced potatoes under cool water to remove excess starch.
More Tater Tricks
For even smoother, creamier potatoes, simmer the slices in a mixture of milk and cream after parboiling and rinsing them. Different diners prefer various textures and consistencies, so experiment with a combination of smoothing methods -- including soaking, rinsing and simmering -- until you find the tater tricks that work for you. Do not soak potatoes before frying them; the starch you want to remove for mashed potatoes actually helps fried dishes reach their maximum crispiness.