Rösti (Swiss Potato Cake)

Let's set the record straight: Rösti are not merely potato pancakes with a Swiss-German name. They are, quite specifically, potato pancakes made from pre-cooked potatoes. I wouldn't blame anyone for not knowing that. Read almost any recipe that isn't from a knowledgable Swiss-German source, and you'd almost universally be led to believe that rösti are made like any other potato pancake, by grating raw potato, seasoning it, and cooking it in a skillet with a good amount of fat until crispy.

Where did this confusion come from? I'm not sure, but I'd imagine it happened like so many things, where the vague idea of something—and in this case the perceived coolness of its name—took precedence over making any effort to actually learn about it. Next thing you know, American chefs and recipe writers are slapping the name "rösti" on every last thick and golden potato pancake and getting bonus points for seeming worldly.

My first inkling that there was more to rösti's story came when I was doing some digging into whether there were any meaningful differences between Ashkenazi Jewish latkes, Swiss-German rösti, and French pommes Darphin. Are size and thickness the distinguishing characteristics? Binders and seasonings? Cooking fats? Cutting through a fog of poorly researched recipes, I came across a couple of sites that seemed to suggest rösti are supposed to be made with cooked potato, but I was having trouble confirming it. Fortunately, one of my best friends' mothers is Swiss-German, so I called her up.

Right away she confirmed that rösti should be made with a cooked-potato base. "Raw potato is like a newer version, my mother would make that too, but she'd call it raw rösti," she told me, making it clear the underlying assumption was that real rösti was made from cooked potato. "Raw doesn't taste the same, more like a latke."

She told me about its roots as a hearty farmer's breakfast. "The farmers' wives used to make the rösti for after they came in from milking the cows, they needed a substantial breakfast. There were eggs and bacon, that's how my grandmother had hers, that's how it was on the farm." She also told me about how it became popular in restaurants throughout Switzerland and settled into a national habit. "In the 50s, it was in every restaurant: sausage and rösti, schnitzel and rösti, geschnetzeltes (very thinly sliced veal in cream sauce) and rösti. It's the most common food in Switzerland, nobody ever made a big deal out of it."

This all may seem like much ado about nothing, but having cooked my fair share of potato pancakes in a variety of forms, I can attest that rösti, when made with cooked potato, is remarkably different from its raw-potato counterparts, and, dare I say, one of the very best potato pancakes as a consequence of this detail. Par-boiling the potato delivers a number of advantages over raw:

• First, you don't have to worry about the oxidation and discoloration common to other potato pancake preparations, which means you can take your time between grating and cooking.
• Second, while preparing rösti requires extra time to boil whole potatoes and fully chill them before grating (more on that below), the potato pancake itself cooks up quickly and easily, thanks to the already tender, pliable, and—to state the obvious—cooked potato shreds. This is especially helpful given that rösti is typically a thicker pancake than something like a latke or hash brown.
• Third, you don't have to worry about squeezing out excess water the way you do with salted shredded potato. Because the potato is already cooked, its starches are gelatinized, meaning almost all of the potato's natural juices are tied up in the swelled starch granules.
• Fourth, the internal texture and flavor of rösti are different from a potato pancake made from raw spuds. Largely because of the gelatinized starch, you don't get that same slick texture from released starchy juices on a raw potato's cut surfaces, which thicken into a viscous gel as the pancake cooks.

Some of you are probably wondering now whether there are any shortcuts. Do you really have to boil the potatoes whole in their skins, or can you save time by peeling and cubing them first? And is that chilling step really necessary?

The short answers are yes, and yes. Cooking the potatoes whole and skin-on prevents excess water from seeping into the flesh (assuming you don't cook them so long the skins split), ensuring a dry-enough cooked potato when it comes time to grate and cook it. It's also a lot easier to grate a whole potato—just think of how hard it is to grate the last nubbin of just about anything, then multiply that across a pile of pre-cut cooked potato cubes. You'll be much faster with a whole potato in your hand.

As an experiment, I tried grating some potatoes raw, cooking those shreds in the microwave (much faster than boiling a whole potato), and then making rösti from that. Unfortunately, that doesn't work well either. As soon as you cut up the raw potato, you break open its cells and release starchy juices. When those juices heat, they thicken into a sticky slurry that coats the shreds and has textural ramifications on the finished product—and not particularly pleasant ones at that.

As for chilling, it's just science. As the gelatinized starches cool, they go through a process called retrogradation, in which they re-crystallize and harden. This is the very same process that causes bread to stale and tender cooked beans to grow surprisingly firm in the fridge. For rösti, the retrogradation of potato starch is a helpful step, firming up the par-cooked potatoes just enough to make grating them into distinct stands—and not a pile of mush—possible.

What About Add-Ins and Variations

The basic rules of rösti are what we have already outlined: Par-boil your potatoes; peel, chill and grate them; cook into a pancake. Here are some additional notes to consider when making rösti:

• Fat is flexible: This recipe calls for butter, but you could use oil, duck fat, bacon fat or lard, etc. Each will influence the flavor of the rösti.
• Add-ins are possible: I watched one video where a cook mixed grated raw onion into the cooked shredded potato before finishing in the skillet, but the result was rösti that had little burnt bits of onion all over its surface. If you want add-ins like onion or bacon bits, better is to use a technique my friend's mom suggested: Cook your add-in first (sauté the onion, crisp the diced bacon). Then put half the shredded potato in the skillet, spread a layer of the cooked add-in on top of that, then pile the remaining potato on top. That way, the add-in gets sandwiched inside the rösti, preventing it from burning as you brown the surface of the rösti deeply.
• Capture the crispy bits: As you fry the rösti, little crispy bits of shredded potato will naturally fall off. Feel free to mix them back into the potato cake as it cooks, so that the crispy bits become incorporated into the larger mass. The rösti is malleable enough to re-form it after mixing the crispy bits in.
• Nonstick works well: As a proponent of more rugged cookware like cast iron, carbon steel, and stainless-steel, I tend to avoid recommending nonstick unless it offers a big advantage (say, for eggs). With rösti, I found nonstick worked just as well to deeply brown and crisp the potato compared to cast iron, and has none of the risk of the potato sticking, which is a pretty big advantage. I'd recommend it here, though you absolutely can use cast iron or carbon steel if you prefer.

Regardless of what you do, one thing is clear: If the potato isn't double-cooked, it's not truly rösti. It's just a potato pancake.