One of the most prolifically adaptable plants around has got to be the stinging nettle, which is at home in Europe, Asia, North America and northern Africa. It’s also one of the most prolifically named: Urtica dioica goes by several other species names that appear to be in a state of constant revision. (Maybe I can get a little help from the taxonomists on this one–is this a case of many plant morphologies with a single genome that people have confused for unique species, or is it a case of many people having something they call “stinging nettle” near them, that’s actually a range of species within the Urtica genus?)
By any alias, the stinging nettle is an interesting mix of benevolent and malicious–an intensely nutritious food plant chock full of iron, calcium, and vitamins A and K (see recipe below)…but guarding its benefits behind an armor of fine stinging spines.
The basis for the sting in stinging nettle is debated more than I realized. I had always learned that the sting was from formic acid, the same molecule that makes ant bites so painful. And certainly formic acid is present in the spines. But so is histamine (an inflammatory molecule produced by your body in response to injury, which tells you you’ve been hurt. It’s deployed in response to irritants, which is why you should blame your body for all the itching, and not the mosquito that just bit you, or the poison oak you just blundered into). The spines also contain several other acids, including oxalic and tartaric acid, that may contribute to the unique bite of a nettle sting (you know. If becoming a connoisseur of stings is your thing).
Undaunted by the possibility of stings, I recently set out to do a culinary experiment on a patch of stinging nettles that grows near the Stanford succulent garden. This raised another question, highlighted recently by my friend TC, who asked “so when you find these edible plants, exactly how sure are you that the plant is what you think it is?” And usually, the answer is: completely. Most of the plants I’d eat from the wild are things I grew up with, and have been eating since I was a kid. I’m as certain as I would be if someone asked me whether I was sure a dachshund was a dog and not a weasel.
But nettles are hazier ground, since I’m usually trying to avoid them rather than find them, and they’re a bit nondescript until you get too close. I was maybe 95% sure these were nettles. Happily, though, in the course of collecting them (armed with nitrile gloves), I pulled a little too tightly on one of the stems and fetched myself a taxonomically unambiguous sting on the finger. The spines on the leaves are almost nonexistent in the early spring, but the ones on the stems are robust enough to go through thin gloves, so take care and also bring scissors if you’re going collecting!
Once I had my harvest gathered, I tracked down this recipe for nettle risotto from Mariquita Farm, which looked pretty tasty. It turned out reasonably well, but butter, onion and parmigiano are fairly strong flavors, so I’m not sure this is the best showcase for nettles.
RISOTTO WITH NETTLES (my comments are in italics)
2 cupfuls packed nettle leaves, stems removed–use scissors and wear gloves!
2 cups chicken stock (I used broth, so I omitted any extra salt, since the broth reduces so much in the course of cooking).
2 cups water
2 tablespoons canola oil (olive oil has a low smoking point, so it’s actually bad for sauteing, there are harmful fatty acids formed when it breaks down in heat)
1 small yellow onion, chopped
1 cup Arborio rice
3/4 cup dry white wine, preferably Sauvignon Blanc–I left this out, but no harm done, I feel.
Salt and freshly ground black pepper–no salt if using broth
¾ cup finely grated Parmigiano Reggiano
1 tablespoon unsalted butter
Blanch the nettles briefly in hot water to quench the stings, then chop finely.
Heat the water and chicken broth together until simmering. Keep at a simmer during the next steps.
Heat the oil in a heavy saucepan or casserole over medium heat. Add the onions and cook, stirring occasionally, until soft, about 5 minutes. Add the rice and stir until rice grains are toasted (they’ll look opaque. This step helps the rice absorb liquid).
Add the wine and simmer, stirring constantly, until the wine has reduced by half, 3 to 4 minutes. Add the nettles. Add a few ladlefuls of stock to the rice and stir to wipe the rice away from the sides and the bottom of the pot. Stir until most of the liquid has been absorbed. Add another ladleful of stock and continue to stir until the liquid has been almost absorbed. Continue to add stock and stir in the same manner until the rice is soft and you’ve used nearly all the liquid, about 20-25 minutes, depending upon the variety of rice. Season with salt and pepper. Remove the pan from the heat and add a last ladleful of stock, the butter and the half of Parmigiano. Cover the pan and let sit covered off the heat for 5 minutes.
Remove the cover and stir. Serve with wine and extra Parmigiano–I also used a sprinkle of red pepper flakes.
For the next round, I’ll probably try sauteing the nettles with butter and shallots, just as you would spinach or collard greens. I’m also looking forward to the prospect of nettle tea!