When potatoes are mashed, starch is released. The more you work the potatoes, the more starch gets released. When too much starch gets released, the potatoes become gummy, gluey, and unappetizing.
Overcooked or insufficiently drained potatoes can become sticky, as can the wrong kind of potato. But the main problem is overworked spuds. The science is simple: Boiled potatoes develop swollen starch cells. When ruptured during mashing, the cells release starch.
Your potatoes may taste fine, but the thick, gloppy texture could be more than your guests can stomach. Aside from using the potatoes to create a new kind of side dish, the best thing you can do is learn what causes this gluey mashed potato mishap, then start over or apply this knowledge to your next batch.
Start With the Proper Potato
You want to 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.
A quick rinse under cold water can wash away much of the surface starch. More starch is removed from a cut potato than a whole peeled potato, because a greater surface area is exposed on cut potatoes. Soak them in cold water for as long as a few hours to remove more starch than by rinsing alone.
Overcooked potatoes aren't always dry and hard, as it's possible to overboil a potato too. When you do so, more water is absorbed by the potato. Then, when you go to mash them, the water releases, resulting in that sad, soupy mess you may want to toss in a compost pile far, far away.
Throwing in a cold stick of butter and a splash of milk straight from the refrigerator will immediately cool down some of the spuds, which will prevent a creamy, smooth mash. If you take the time to slowly heat milk or heavy cream and butter in a small saucepan on the stove, you'll have much better results.
Make sure the potatoes are cut to the same size for even cooking. Rinse twice to remove the starch: rinse once before cooking and one more time after cooking. Start with the potatoes in a pot of cold water (instead of pre-boiling the water) to ensure even cooking from the outside in.
The more you mix, the denser your mashed potatoes will be.
Otherwise you can still make fluffy mashed potatoes without a ricer by using a Food Mill instead. Both will work best since it breaks down the potato without excessive mashing. Avoid using a blender or food processor for this reason.
Always start potatoes in cold water.
Dropping them into boiling water is a bad idea because the hot water will cook the outsides of the potatoes faster than the insides, leaving you with unevenly cooked taters. By the time they've fully cooked to the core, the outsides will be mushy and start to flake apart.
Overworking the potatoes.
When too much starch gets released, the potatoes become gummy, gluey, and unappetizing. Overworking the potatoes can happen in a couple ways: either by simply handling them too much, or by using a food processor, blender, or similar tool, which mixes the potatoes too aggressively.
Visual signs: The potato skin will start to wrinkle when over cooked. The potato, when wrapped in foil or placed on the bottom of a pan will have a dark brown spot on the bottom, a sure sign of over cooking. Foil traps the moisture in the potato causing the skin to be wet and the inside flavorless or gummy.
As potatoes are quite porous, when they spend time in a big pot of water, they tend to soak up a lot of the water they're in. With all that soaking, it makes it so potatoes retain water and may release it in the finished salad product, leaving you with a mushy end-result.
They are low in starch and high in moisture and sugar. These potatoes are usually small and round in shape, although some varieties can be bigger. Waxy potatoes are good for boiling because they hold their shape well, and their firm yet creamy texture makes perfect potato salads!
Soaking potatoes in water helps remove excess starch. Excess starch can inhibit the potatoes from cooking evenly as well as creating a gummy or sticky texture on the outside of your potatoes. Cold water is used because hot water would react with the starch activating it, making it harder to separate from the potatoes.
Soaking potatoes has benefits beyond removing a small amount of starch. Soaking reduce levels of acrylamide, a chemical formed when foods high in starch are fried or cooked at high heat, such as baking or roasting. Acrylamides may contribute to cancer in animals and may have health risks for people.
Raw potatoes should be firm to the touch with tight skin that's free of large bruises, black spots, or other blemishes. If a potato has become soft or mushy, you should throw it out. Though it's normal for potatoes to smell earthy or nutty, a musty or moldy odor is a hallmark of spoilage.
You may think the dish is ruined, but don't fret. Here's a tip on How to Fix Over Boiled Potatoes. Drain the potatoes and place them back into the pot over medium heat and stir them. Stirring removes the excess water and dries them out.
It is easy for you to check whether your potatoes are undercooked. Pierce them with a fork which should smoothly go through and slide off easily. However, it is not advisable to use a knife since it is sharp and can cut through food.
Soupy, watery mashed potatoes usually happen because the cooked potatoes were cut into pieces that were too small, weren't drained well enough, or were overcooked. Fix them: Scoop the watery mashed potatoes into a pan and stir constantly over low heat to evaporate the excess liquid.
We consider Yukon Gold potatoes the best choice for classic dense mashed potatoes. Their rich texture and subtle creaminess make them great for all of your mashing needs. A true all-purpose potato, they're also good for shredding, roasting, grilling, blending (?!), and shingling.
To make Gordon Ramsay's mashed potatoes, boil potatoes for half an hour and set them aside. Then, melt butter in a pan and cook garlic in it. Add milk to the pan and stir for a minute. After that, add the warmed milk, chives, salt, and pepper to the potatoes and mash them until smooth.
For most potato dishes it's important to add the potatoes to cold water and allow the water to come to a boil with the potatoes in the water. The potato starch can react as soon as it comes in contact with hot water, which will promote uneven cooking and mealy potatoes.
“Salting the water not only seasons the potato, but it also allows it to boil to a hotter temperature. This in turn cooks the potatoes' starch more thoroughly, resulting in a more creamy texture [for mashed potatoes],” says Sieger Bayer, Chef and Partner at The Heritage.