The technique is an open secret among those to whom have the most to gain or lose from the optimization of food. Food professionals like chefs and caterers know it, because flavor is money. Savvy home economists, who make it their business to satisfy demanding palates on the cheap, know it too. I learned the technique from a farmer, who learned it from a farmer—the kind of farmers that make it their pleasure to enjoy their harvest prepared in a way that celebrates the local terroir.
Ukrainian food bloggers know it, because Ukraine could be a euphemism for "cold weather potatoes," and this technique will change your potatoes forever. I can only hope my Ukrainian ancestors knew it. Of course they did. They probably invented it.
When my thoughts turn to roasted roots, it means I've officially given up on summer, which is not something I do easily. And by summer I mean the food of summer. The tomato plants are dead. The hens are getting lazy. I'm racing to get my garlic in the ground before it freezes. My furnace still isn't getting any action, though, because my oven is heating up the house.
The heat produced by a load of roasting roots is a dry heat, much different from the steam bath of the simmering soup pot. If all goes well, that dry heat helps create a crispy brown exterior. Inside, we want more of a fluffy heat, if we are thinking deeply about what we want inside a roasted root.
We want a roasted root to taste like a perfectly roasted potato. That's a tall order, since most cooks can't even properly roast a potato.
Most recipes for roasted potatoes (and roots) direct the cook to heat them until brown, but that's not enough. How it browns matters.
Many suggest stirring, or solving every problem with more oil. Even if they are brown and crispy on the outside, the interiors may be gooey, or chewy, or bland like a steak house baked potato. They may be dry, or mushy like a mashed potato. They all have the same thing in common: the technique was not employed.
The potatoes must be soaked or parboiled before roasting. This washes away excess starch and allows them to cook perfectly.
Given how foolproof a pathway it may be to carb-o-liscious bliss, I'm baffled at how few cooks do the pre-soak. Google roasted roots and peruse the first page of results, recipes from the likes of Epicurious, Genius Kitchen, Food Network, Eating Well and the New York Times. Not a single recipe mentions the pre-soak. (And many of them seem coincidentally quite similar). If you Google roasted potatoes it's the same: zero mention of soaking the spuds after cutting them.
There are variations to the soak. Some cooks do a parboil instead, so the potatoes will cook more quickly in the oven. After a parboil with salt and vinegar, Kenji Lopez-Alt of Serious Eats advises to rough up the potatoes so they are coated with a starchy foam, which browns into something of a cross between a Pringle potato chip and the skin of a perfect piece of fried chicken.
But for all of the gains he makes in the skin department, the insides end up a bit overworked, if only compared to when soaked in cold water.
So cooks must choose between perfect insides or perfect skins. Most would probably choose the crust with nooks and crannies that break into a million golden pieces when you bite, even if the inside has lost a certain integrity.
When I have a big assortment of roots, I parboil, because when they are all cooked together, it creates a starchy mix of all of the constituents, as if they had all been mashed together. This mishmashes veneer absorbs the oil and spices, coats the pieces and cooks into a tasty crust.
But if I'm doing potatoes alone, especially purples, golds and russets, I do a pre-soak in cold water. The recipe below details the parboiling of myriad roots, but includes directions for the potato soaking options.
Roots that Rock
Each type of root is different. Within the potato category alone, starchy ones like russets or Yukon golds will outperform waxy types, like fingerlings or reds. My favorite potatoes to use, in both soaking and parboiling contexts, are purples, the starchiest of all. When soaked, they blow up the fattest, coming closest to erasing all the angled cuts, like an ankle so swollen you can't see the bones.
When it comes to choosing roots, the earth is the limit. Use whatever you like, though be advised some can be problematic. I avoid roots that are too watery, like onion, or roots that are bitter, like garlic or rutabaga, as the bitterness can intensify. I avoid red beets, which will stain the entire tray, even if you don't mix them together. As for squash, honorary root, I like 'em starchy, like my spuds. Kabocha and Sunshine and Buttercup varieties are my favorites. Carrots, yams, sweet potato, parsnip, and celeriac are all good choices, although many of these will stay moist inside and won't crisp up. Ditto for kohlrabi, another honorary root.
Ingredients
2 pounds roots, peeled and cut to roughly the same size
3 tablespoons salt
1 teaspoon baking soda
1 tablespoon garlic powder
1 tablespoon smoked paprika
1 tablespoon black pepper
1-2 teaspoon ground cumin
4 tablespoons olive oil
Optional: fresh garlic and butter for dressing; ketchup, mayo and hot chile flakes for dipping.
Add 2 tablespoons salt and the baking soda to a gallon of water and bring to a boil. Bring to a boil and add the roots. Boil for ten minutes. Drain the roots, and allow to steam for a minute. Preheat the oven to 425 degrees, along with a tray.
Mix the cumin, black pepper, garlic powder and 1 tablespoon salt, and add two tablespoons of this mixture to the still-warm roots, and stir them around roughly, to help disintegrate the soft, starchy exteriors. Add the olive oil and stir again.
Spread the roots upon the hot tray and hear them sizzle. Put as many pieces on the tray as possible without letting any of them touch.
Bake for 30 minutes. Remove the tray and inspect. Turn each piece so a different side faces down, and bake again, removing pieces periodically and testing them, until you decide they are done.
Serve with some kind of tangy sauce or dip. I like a mix of ketchup and mayo. If I really want to impress, I melt some butter and a pan and saute fresh garlic and green herbs, like parsley, sage, rosemary and/or thyme. Toss the roots in the garlic herb butter, and serve.
Pre-soak variation
Don't peel the roots, but do peel squash, if using. Soak them in a gallon of water with the same amount of salt and baking soda. Cook until they whistle with the sound of 100 little blimps with pinpricks.
Serve with garlic herb butter or ketchup mayo, and your finest white wine.
