Mashed potatoes make a delightful side dish—creamy, fluffy, and filled with buttery flavor. But despite good intentions, they can easily turn out gummy, heavy, and nearly inedible. Follow a few tried and true tips and tricks to keep your mashed potatoes light and delicious.
Start With the Proper Potato
Russets, also called Idaho or baker potatoes, make the fluffiest mashed potatoes. The high starch content and low moisture results in a drier texture and lighter mash. Avoid low-starch, high-moisture potatoes such as red bliss or white potatoes, which need more exuberant mashing to break them down, potentially overworking the starch and turning them gluey.
Yukon Gold potatoes contain a medium level of starch and relatively low moisture, but with a thinner skin and a naturally creamier texture. Some cooks prefer to give up some of the fluffiness of russet in favor of the Yukon Gold's creamier texture, naturally buttery flavor, and attractive yellow hue. For the best of both worlds, consider combining the two. Yukon Golds also make a good choice for those who prefer to keep the skins.
Scrub and peel raw russets, then cut them into uniform 1- to 2-inch chunks so they cook evenly. Place them in a pot with cold water to cover, then bring them to a full rolling boil. Reduce the heat slightly and keep them at a constant low boil for about 20 minutes or until you can insert a knife with no resistance. Drain them thoroughly, then return them to the hot pot and gently move them around for a minute or two until all of the surface moisture evaporates.
Alternatively, you can bake scrubbed russets in their skins in a 400 F oven for about an hour, or until a knife slides in easily. Let them cool, then split them in half lengthwise and scoop out the flesh for mashing. This method eliminates the need to peel the potatoes, cutting the prep time significantly.
Rely on Trusted Techniques
Mashing potatoes with a blender, hand mixer, or food processor breaks down the cells and releases starch, giving you mashed potatoes with the consistency of wallpaper paste. A ricer, food mill, or hand masher poses less of a threat than those metal blades whirling at thousands of revolutions per minute. If you plan to use a food mill, you can skip the step of peeling the potatoes before you boil them. The ricer and food mill both yield a silkier texture than a hand masher, which may leave a few smallish lumps. In all cases, you want to process the mashed potatoes as gently as possible to avoid working them into a state of gumminess.
Keep melted butter warm before adding it to the potatoes. Similarly, you should heat any cream you plan to add to just before steaming, then mix it into the potatoes while it's still warm.
How to Fix Gummy Potatoes
Unfortunately, once the starch in your potatoes has been released, there is no way of getting rid of it. Therefore, there is no way to "fix" gummy potatoes. This is why it's so crucial to mash them gently so that your potatoes don't turn gluey in the first place.
It's been suggested that you can, if not fix, at least remedy a batch of gluey mashed potatoes by adding some properly prepared (i.e. nongluey) mashed potatoes and combining the two batches. This will certainly result in a larger batch of potatoes that is in the aggregate less gluey than before. But if you're going to go that route, you'd be better off simply serving the fresh batch of nongluey mashed potatoes instead, and just discarding the gluey ones.