How to Make Mashed Potatoes Properly

Why do my mashed potatoes look like glue?

To understand this, you first need to know a little bit more about potatoes. Their flesh is composed of millions of small cells attached to each other with a kind of plant-based cement.

These cells contain water and grains of starch. Keep in mind that starch is found inside the cells. During cooking, the plant-based cement softens, allowing the cells to slide over one another, as if a brick wall has suddenly turned into jello. The potatoes have become tender and are now ready to be mashed.

Everything is perfect so far. Break out the potato masher and get to work. The purée looks great when you first start mashing it, but as you continue, it seems to start sticking. You add milk and keep mashing but it gets even stickier. What’s happening?

By mashing, the cells begin to separate from one another and this gives the mixture its puréed consistency (the brick wall has collapsed). But if you mash for too long, the cell walls begin to break and release their starch into the purée. The more mechanical the mashing motion, the more starch will be released. In short, do not use a food processor to mash potatoes.

Tips for the perfect mash

What difference does it make if starch is now on the outside instead of the inside of cells? It’s as if you added cornstarch or flour to your mashed potatoes. This thickens the mixture and makes it stick together due to the starch grains that swell and turn gel-like after coming into contact with hot liquid. What can be done to prevent this disaster? Here are a few tips.

1. The choice of potato

There are two types of potato that exist: floury and waxy. Each has its own characteristics and culinary uses.

• Floury potatoes: These are rather long and brown. The classic example is the Russet potato (also known as the Idaho). Potatoes with the word “oven” on the bag are also floury potatoes. Their flesh is soft and crumbly, some would even say fluffy, after cooking. They come apart easily, making them an excellent candidate for mashing. You don’t need to work too hard to make a smooth mash, so starch is less likely to escape.

• Waxy potatoes: These usually have a round shape and are red or brown. You’ll often find the word “boil” on a bag of waxy potatoes. Their flesh is thin, smooth and creamy (like wax) and does not fall apart during cooking. It’s the ideal choice for salads, stew and boiled potatoes. This type also makes a good purée, but you have to make sure you don’t mash it too much. The yellow-fleshed Yukon Gold variety is known for producing an excellent mashed potato.

2. The mashing technique

Reminder: You want to separate cells, not cause them to break and release starch grains into the mash, making it sticky. The ideal tool for this is a pestle or potato masher. One trick is to mash the potatoes with a pestle to break down the big pieces, and then finish off with a hand mixer to give the purée a lighter texture.

Another trick: Do not overcook (the cells will be less damaged), drain the potatoes well and let them sit and cool a few minutes before mashing (there is less risk of cell breakage when they are warm).

3. The addition of liquid

Liquid, usually milk, is added to make the mashed potatoes creamier. But if it’s moisture you want, why not simply add water? There’s taste and nutritional value to consider but, according to French researchers, it’s possible that milk contributes to a successful mash.

In fact, milk contains large protein molecules (casein) which insert themselves between starch grains and keep them from swelling too much or turning the mash into a sticky clump. There’s your scientific explanation for one of the most common culinary practices.

With these tips, you can now make delicious mashed potatoes following these recipes:

VEGETABLES

Minted Mashed Potatoes

VEGETABLES AND GRATINEES

Spinach and Mashed Potatoes au Gratin

THE BEST

Mashed Potatoes (The Best)

CORN

Mashed Potatoes with Corn and Harissa Butter