Here's how this sticky state of affairs happens: Cooking causes the starch granules within the potato cells to absorb water and swell. Some cells will inevitably burst, releasing tacky gel that helps give mashed potatoes their cohesiveness.
Too much starch is what makes mashed potato gluey and ruins its fluffy texture. If you want to keep your mashed potatoes from getting gummy the best way to do this is using a potato ricer. Otherwise, you can still make classic fluffy mashed potatoes without a ricer by using a Food Mill instead.
According to Serious Eats, when your mashed potatoes end up with a pasty or a gluey consistency, it's due to an excess of starch. As a result, limiting the amount of starch in your dish is the key to nailing perfect mashed potatoes. Luckily, there's an easy way to do this: Don't overwork your potatoes.
Too much — or too vigorous — mashing will produce gluey potatoes. Your best tool is an old-fashioned masher, fork, ricer or food mill. If you've already done the damage, turn pasty potatoes into a casserole: Spread them in a baking dish, drizzle with melted butter and sprinkle with grated cheese and breadcrumbs.
Fix them: Scoop the watery mashed potatoes into a pan and stir constantly over low heat to evaporate the excess liquid. If the potatoes are really watery, you can add either cornstarch or instant mashed potatoes a half teaspoon at a time to help the spuds thicken to your preferred consistency.
Once mashed potatoes reach the glue stage, there's no going back. Your potatoes may taste fine, but the thick, gloppy texture could be more than your guests can stomach.
You can use what you have on hand: Flour, cornstarch, or powdered milk are all solid options that are probably already in your pantry. Potato flour and potato starch would work as well. Stir in the thickening agent gradually, about a tablespoon at a time, until the potatoes have reached your desired consistency.
The best potatoes to use for mashed potatoes are Russet potatoes or Idaho potatoes because of their high starch content. Yukon gold potatoes are another good option, the texture of Yukon gold is a bit more buttery and not quite as starchy.
But the most essential suggestion, per Bon Appétit, is always to salt the water you are boiling your mashed potatoes in. It acts as pre-seasoning, and Bon Appétit recommends adding a full cup of kosher salt to the boiling water.
If you've been adding too much milk or butter, try cutting back to achieve the perfect consistency. Let your mashed potatoes sit for a few minutes before serving. As they cool, they will thicken up slightly.
To thicken mashed potatoes, you can add a thickening agent like cornstarch, flour, powdered milk, or tapioca. Add one tablespoon at a time until you reach your desired consistency. You can also add heat, more potatoes, or even strain the mashed potatoes in order to reach your desired consistency.
Adding additional liquid, such as milk, plant-based milk, or vegetable broth can also help by keeping the potatoes from drying out. To reheat mashed potatoes in the oven: Place your leftover mashed potatoes in an oven-safe dish. Stir in melted butter, melted vegan butter, or oil and milk/cream, vegan milk, or broth.
Add a Thickening Agent
This is the most common, and perhaps the simplest way, to thicken mashed potatoes. You can use what you have on hand: Flour, cornstarch, or powdered milk are all solid options that are probably already in your pantry.
If your mashed potatoes are done too soon, they could cool or dry out before the meal. Start the potatoes during the last hour of cooking, when you start the gravy. If that's too much, keep mashed potatoes warm in a slow cooker. Stir in a little warm milk or butter for added moisture.
How Long to Boil Potatoes. The cooking time is going to come down to size — whether your potatoes are large or small, cubed or whole. In general cubed or small potatoes will take about 10 to 15 minutes to boil, while larger, whole potatoes will take between 20 to 25 minutes.
If this occurs, the outlet recommends correcting course with more fat: Adding more liquid in the form of melted butter, extra-virgin olive oil, cream, or full-fat milk.
Never try to mash up cold potatoes. It has to do with some chemical-y thing with the starch. If your potatoes go cold, heat them up again (in warm water, a microwave) and then try to mash them.
Add a Thickening Agent
This is the most common, and perhaps the simplest way, to thicken mashed potatoes. You can use what you have on hand: Flour, cornstarch, or powdered milk are all solid options that are probably already in your pantry.
If they're undercooked, you'll have pockets of crispy potato chunks-—a big no-no for classic fluffy mashed potatoes. If you overcook them they disintegrate and your potatoes will be soupy.
Feel Test. Soft potatoes are still alright to eat, but if it's mushy, leaking liquid, or too soft that it can't hold its shape, it's better to discard it. After feeling your potato, check if it smells rotten—sometimes, the softness shows that the inside has decayed.
That's liquid you DON'T want, since it'll make your mash all watery. 6. Do NOT add cold liquid. Make sure the milk or cream you add to your potatoes is HOT.