Making mashed potatoes is one of those tasks where sophisticated kitchen gadgetry does not necessarily do the job better than a simple utensil. Choosing the right potatoes and using a simple technique to prepare the mash make the process easy to complete with the humble fork.
While gourmet chefs inevitably graduate to the potato ricer, which expunges light, fluffy threads of potato, purists stick with a masher or fork, which allows for a coarser mash with the occasional lump for texture. A light, flexible fork will not do the job, however, and takes a toll on the wrists. Use a heavy fork with an easy-to-grip handle and thick tines, working in warm butter or cream as you go. A further advantage of a fork is you can finish off the mash with a wavy design by dragging the tines over the surface, which is great for building a crust on a baked cottage pie, for example.
Potatoes are made up of water and starch, and the best mashed potatoes come from high-starch potatoes such as Yukon gold or russet, also known as Idaho. Waxier specimens such as red skin or new potatoes are more likely to produce a thin, uninspiring gruel. Because the fork does not whisk through skin, peel the potatoes before boiling or cook them with the skin on then slide off the skins with the edge of a knife blade once they are cool.
Do not cut the potatoes into small chunks for boiling as this allows them to absorb excessive amounts of water. Instead, boil equally sized pieces in salted water until the internal temperature is 200 degrees Fahrenheit. Any less and there will be uncooked sections that frustrate the whisking process. Once cooked, immediately drain the potatoes in a colander, then return them to the pot and cook uncovered for a couple of minutes maximum over a low heat to dry out the potatoes. Never leave the potatoes in the boiling water or they become swollen and watery.
Transfer the potatoes to a bowl with an easy-to-grip handle and add warm butter and milk as well as any herbs, gradually working in the mixture with the fork until you achieve the desired consistency. Typically, the point of using a fork is to maintain a fairly stiff texture, so just a lump of butter and dash of milk suffice. Whisk steadily with the fork but not too vigorously. The starch granules in cooked potatoes are swollen but beating too much causes the starch to release, giving the mash the consistency of wallpaper paste.