Salt is a change agent. It’s hard as rock, but water soluble. It can melt ice on slippery winter sidewalks and speed up the ice cream making process in the summer. It makes flavors pop and fermented food shelf-stable. And it can upcycle your root vegetable peels from the compost bin to the dinner table as a finishing touch.
Yes, clean (preferably organic) root vegetable skins are completely edible. Drying out shaved beets, carrot, celeriac, daikon, ginger, parsley root, parsnip, radish, rutabaga, sunchoke, salsify, and turnip peels in a moderate oven—even as you’re roasting the vegetables they once contained—and grinding them up finely before putting them in a jar with some sea salt gives a home cook an easy way to layer flavor into all sorts of dishes.
A sprinkle of carrot-ginger peel salt will add more zing to Carrot Ginger Zinger Soup, for example. Combining dried and pulverized celery root peels with celery seeds and salt will amplify the underlying flavors of Celeriac Puree. Giving each potato pancake a sprinkle of parsnip peel salt just after it comes out of the hot oil will help the carrot’s paler cousin hold its own in Sweet Potato Parsnip Latkes with Feta and Leeks. And since French peasants likely did not waste even a morsel of food, you might also use the peels of the beetroot tapped for French Peasant Beets to make a vibrant finishing salt. These salts embody age-old frugal eating with a modern eye toward food waste reduction.
The process of making flavored salts from root vegetable peels is a simple one. Scrub the root vegetables really well with cold water. Use a vegetable peeler to remove the skins with as little of the flesh attached as possible. Spread the thin peels in a single layer on a baking sheet, and roast them on the top shelf in a moderate oven (about 325-50° F) until they begin to dry out, curling at their edges but not burning at the point where they touch the pan (about 15 to 20 minutes).
Remove the peels from the oven and cool completely before stuffing them into a spice grinder to pulverize them. Typically, a cup of dried peels will process down to a couple tablespoons of flavored dust. Once the peels are finely ground, add 1 teaspoon flaky sea salt to the grinder and pulse it into the peel dust until it’s all the same consistency. Every heaping tablespoon of this resulting mixture will flavor 1/2 cup of additional sea salt.
Once you’ve flavored salt in this fashion, it best to let them sit a couple of hours before using for best results. But once flavored, these salts can sit in the cupboard in an airtight jar for months for you to sprinkle about your dishes when you see fit.