In Absolute Best Tests, our writer Ella Quittner destroys the sanctity of her home kitchen in the name of the truth. She's boiled dozens of eggs, seared more Porterhouse steaks than she cares to recall, and tasted enough types of bacon to concern a cardiologist. Today, she tackles mashed potatoes.
The world's first potato moved from a pocket of dirt to a mouth sometime between 8,000 and 5,000 B.C.E., in Peru. Some millennia later, Spanish conquistadors brought the tubers back to Europe, resulting in the earliest recorded recipe for mashed ones. It came courtesy of The Art of Cookery Made Plain and Easy, written in 1747 by Hannah Glasse, and went something like this: Boil your potatoes, then peel, then mash within a saucepan. Add a pint of milk, some salt, stir—with attention to the layer at the pan's very bottom—and a quarter-pound of butter. Stir again. Serve.
Many have tried to hack the humble mashed potato since.
Take, for instance, Jeffrey Steingarten, who documented his attempts two-and-a-half centuries later in a 1997 essay called "Totally Mashed."
"My mashed potatoes still get gummy on me. Sometimes they go cataclysmically wrong, turning sticky and gluey or doughy and pasty, bonding to my teeth and gums and the roof of my mouth," he writes, before sharing his breakthroughs in boiled potato manipulation. (More on that later.)
In 2010, the intrepid J. Kenji López-Alt over at Serious Eats broke down the science behind velvety purées, versus fleecier mounds. His findings? It all boils down to the starch. A few years later, Food52's own Sarah Jampel took to the lab (kitchen counter) to put a handful of masher-less mashing techniques to the test, and our Resident Genius, Kristen Miglore, scouted a clever trick for richer flavor: add the butter before the cream.
But the absolute best way to mash a potato? Out of every single way? I had to know for myself. So with the findings of all the potato pundits before me in hand, I set out to pit 11 cooking and mashing methods against one another. Which would yield a batch so fluffy one could use it as a pillow on the drive home from Thanksgiving dinner? Are creamy whipped potatoes without a trace of gumminess a myth?
And before you say that spending an entire day straight obsessively poking, peeling, and mashing potatoes sounds somewhat unhinged, well—actually, you're correct. I haven't had contact with a human since. All of my friends are potatoes now. Let's dive in.
"Mealy types fall apart into individual cells and small aggregates," writes food scientist Harold McGee in On Food and Cooking, referring to Russets and the like, "so they offer a large surface area for coating by the added ingredients, and readily produce a fine, creamy consistency. Waxy potatoes require more mashing to obtain a smooth texture, exude more gelated starch, and don’t absorb enrichment as easily." Sold: All tests would feature Russet potatoes of a similar size.
"Rinsing the boiled potatoes of excess starch both before and after cooking was the key," found López-Alt when, in 2010, he engineered the fluffiest possible spuds. So to minimize excess starch, all potatoes—except the baked batch—would be peeled, quartered, and rinsed once before their cook method and once before their mash test.
After its initial rinse, each batch of peeled potato quarters (excluding the Instant Pot group, the Jeffrey Steingarten bunch, and that pesky baked one) would make its way into a large pot of cold, heavily salted water—one tablespoon kosher salt per quart of water—and cooked until tender all the way through. Once rinsed a second time, the potato pieces would return to a pot on the stovetop, where they'd be nudged around gently over a low flame to eliminate excess water.
When it came time to mash, each test group would receive (per pound of potatoes): three tablespoons of melted butter, first—based on Miglore's findings—then a quarter cup of warmed cream and a half teaspoon of kosher salt.
The key to keeping mashed potatoes from going the way of glue is to separate their cells, while taking care to slash as few as possible. "The gooeyness develops when you break open the cooked potato cells and literally beat the starch out of them," McGee wrote in 2008, in response to a New York Times reader inquiry.
A hand masher should allow its user to separate the potatoes' cells—not as gently as, say, a ricer, but more gently than something fitted with a blade for slicing, or a paddle for bashing—and offers control over the intensity of cell separation and aggregate mashing relative to a motorized machine.
Hand-mashed potatoes are a lump lover's dream. Wielding the implement by hand—versus a stand mixer fitted with a paddle—did facilitate more textural fine-tuning. And the lack of brutal (sharp or mighty) cell separation made for a fairly fluffy batch. But it'd have been impossible to arrive at a perfectly silky batch with a pleasant texture using a hand masher, because one would inadvertently mash the same cells too many times (glue! glue! glue!) while seeking out unseparated ones.
The tines of a fork should mimic those of a masher, if on a much smaller scale.
Mashed potatoes by fork were neither inedible nor completely enjoyable. Due to the inefficiency of the fork's size—as in, very little ground could be covered by each oscillation of the utensil—patches of the potatoes began to get gluey more quickly, which meant putting an end to the mashing sooner. A lumpier lot was born. The tubers' cells also seemed to absorb less of the melted butter and cream, resulting in a slightly greasy mound of mashed potatoes. Not so greasy that they couldn't be proffered to wine-glutted Friendsgiving guests, but certainly not the best of the bunch.
A potato ricer, first patented in 1909, is essentially a large clamp with which one may extrude a boiled potato through tiny holes.
Food mills—developed around the same time by the Foley Manufacturing Company—force soft foods with the turn of a crank through a sieve-like bottom layer that catches any seeds or pulp too chunky to make it through.
The tamis is a round, drum-shaped utensil with a flat mesh bottom. "It dates to around the Middle Ages, and it's been used in professional kitchens pretty much since," reports the Los Angeles Times. Especially soft foods can be pressed through the fine holes of a tamis using a dough scraper.
In theory, all three contraptions should separate the boiled potatoes' cells more gently than anything from a stand mixer to a tool fit with a blade, and more consistently than something like a hand masher.
Each of the ricer, food mill, and tamis produced mashed potatoes with significantly different textures.
The airiest batch with the best flavor hailed from the food mill, which came with its own pros and cons. Let's start with the cons: It's unwieldy, difficult to clean, hard to store when you're not embroiled in an 11-method mashed potato face-off, and results in the loss of more boiled spud than a masher or tamis thanks to the thin, flat sheets that accumulate around the mill's inner edges while larger chunks pass through its bottom. And the pros? It produced an ethereal mash, and said mash had an inexplicably superior ability to absorb the flavor of the butter and the silkiness of the cream.
Mashed potatoes made by ricer and tamis were largely similar, in that both were somewhat denser than those from the mill, and less dense than those produced in a stand mixer. But the tamis-mashed potatoes were perceptibly smoother than the ricer-mashed potatoes, and despite their lineage from Russets, made for a credible pomme purée stand-in.
Stand-mixer mashed potatoes went from fluffy to just-about-to-be-gluey more quickly than they went from chunky to smooth. Which is to say, the resulting mound of spuds retained some textural diversity. All in all, they were similar to the hand-masher batch, but a little bit creamier and a little bit stickier.
The unremitting blades of a food processor—or, of its handheld counterpart: the immersion blender—rupture the potatoes' cells readily, releasing lots of sticky starch and a sense of impending doom.
Both batches were like glue that had been glued together with more glue. The immersion blender–mashed potatoes had the added flaw of many tiny pieces of unblended spud, floating throughout.
"Any cookbook that sanctions the use of a blender or food processor for mashing should be carefully shredded," writes Steingarten. Here, here.
"When you bake a potato, the starch granules absorb the moisture within the potato," says The Exploratorium. But less moisture is absorbed overall than would be by a boiled potato. So it's possible that baking potatoes whole, then hand-mashing their interiors with the same amounts of melted butter, warmed cream, and salt could bear the fluffiest, least-waterlogged mash yet.
Plus, McGee says that baked potatoes should deliver more depth: "The flavor of boiled potatoes is dominated by the intensified earthy and fatty, fruity, and flowery notes of the raw tuber," he writes in On Food and Cooking. "Baked potatoes develop another layer of flavor from the browning reactions, including malty and 'sweet' aromas (methylbutanal, methional)."
Baked mashed potatoes were pleasant and fluffy, almost snowflake-like. But because they skipped the initial round of seasoning enjoyed by most other test batches—the jaunt in a tub of salty water—they had a much more muted flavor, despite McGee's note.
Instant Pot mashed potato recipes—in which an electronic pressure cooker is used to steam potatoes before they are mashed—have developed something of a cult following in recent years. (Search the term on Google, and you'll find over 5 million recipes.) The idea is that it's more efficient to soften the spuds at high pressure, before draining the vessel and mashing in the same pot with a hand masher or other preferred tool.
Steaming the potatoes on high pressure mode for 10 minutes produced potato quarters that were much tougher than fork-tender. Accordingly, the mash required more force to achieve any cohesion, and was riddled with lumps.
"Years ago the instant mashed potato industry found that if you precook potatoes in 163-degree water for 20 minutes and cool them, the amount of free starch in the final mash will be reduced by half ... It appears to work like this," writes Steingarten. "Cooking a potato is a two-stage process. The starch swells and gelatinizes within the cells when the potato reaches 160 degrees; then, nearer to the boiling point, the pectic cement between the cells degrades, and the potato can be safely matched. Cooling the potato slices after the starch has gelled causes a process called retrogradation to take place; the starch molecules bond to one another and lose much of their ability to dissolve again in water or milk, even if you later rupture the cells."
Put more succinctly by McGee in On Food and Cooking, "[They] can be made firmer and more coherent, less prone to the 'sloughing' of outer layers when boiled, by treating them to the low-temperature precooking that strengthens cell walls."
So Steingarten suggests the following: Add potato quarters to water that's been brought to 175 degrees. Using cold water as needed, keep the water's temperature around 160 degrees for the next 20 to 30 minutes, until the potato pieces "become tough and resilient and lose their translucent appearance.” Drain the potatoes and transfer to a bowl—run cold tap water into the bowl until the potato pieces feel cool, then leave them there for 30 minutes. Proceed to the final cooking step, such as submerging the potato pieces in actively simmering water until tender. Then, mash, such as with a ricer or mill.
Unfortunately for perfectionists who also have day jobs, these fussy mashed potatoes are nearly perfect when paired with a ricer. They're equal parts fluff, creaminess, and flavor (thanks to salting the water in both simmering phases).
The absolute best way to mash potatoes depends entirely on how you prefer to eat them: If you like them fluffy and somewhat lumpy, use a hand masher. If you like them perfectly smooth and airy, use a food mill. If you like them velvety but not at all gluey, use a tamis. If you have all day or have invited me for dinner and are desperate to impress, use the Jeffrey Steingarten method.
And the absolute worst way to mash potatoes? Use a food processor.