Japanese Knotweed: Laudable Edible
So you thought knotweed was just a miserable, evil, incredibly invasive, unkillable weed, the bane of gardeners. Well….yes, but it is also a laudable edible. Indeed, Bon Appetite tells us that knotweed has appeared on the menus of many high-end restaurants, including Noma, Amass, Agern and Daniel. Years ago, I noticed a new plant growing along a stream that I often followed on my morning walk. In August, clusters of white blossoms appeared, their fragrance as enticing and sweet as jasmine. Only later I learned to despise knotweed as it took over more and more land, crowding out native species and making large areas a monotonous green. Still, last year I learned that knotweed is edible and decided to play with this food this spring. I was pleasantly surprised by its lemony flavor and impressed with its versatility and health benefits.
Health benefits The leaves and stems of knotweed contain resveratrol (famous for its presence in red wine), while the roots probably contain the highest concentration in any plant. Resveratrol is an anti-oxidant and anti-inflammatory thought to protect against a number of ailments including heart disease, cancer, diabetes and Alzheimer’s. Knotweed also contains essential minerals including potassium and magnesium, as well as vitamins A and C. Taste and edible parts Certainly sour, knotweed’s lemony tang is likened to other sour plants such as rhubarb and sorrel. However, they are not related; knotweed is a member of the buckwheat family. The best taste seems to be in moderately large stalks that have been peeled of the fibrous outer layer. Flowers are also said to be tart with crunch. Several sources suggest that very young shoots and leaves from the top of the plant may be eaten. I found their taste bitterly unpleasant and did not use them. Perhaps knotweed taste varies with soil or climate. After reading a number of Internet articles on eating knotweed, I had expected a very sour, possibly unpleasant, taste. But surprise! The peeled stalks had a lovely lemony flavor, quite tasty but rather mild. I’ll taste the flowers when they appear in late summer. Versatility Use it in sweet, sour or savory recipes. Eat it raw or cooked. Use it in everything from wine (according to one source) to appetizers, soups, sauces, pickles, breads and desserts. I used Internet recipes to determine amounts for the appetizer, soup and pickles that I made. It all worked quite well except the attempt to make a dessert. I had in mind something like panna cotta (a suggestion from Michele) so I infused heavy cream with equal amounts of small pieces of stalks. As the result had little flavor, I discarded it, wondering if I had used enough knotweed. Some dessert recipes called for moderate amounts of the plant, but others required rather large amounts, so it is possible that I did not use enough. Perhaps later, when knotweed blooms, I’ll give desserts another try with flowers. Stay tuned. Other considerations Knotweed is not beautiful. When raw, it is a dull, medium green. Cooked, that acceptable green turns to homely (being kind) brown. Raw, the texture is like asparagus. Cooking over high heat melts the shoots and fairly quickly turns them viscous. Gentle simmering seems to take care of that problem. Finding it is easy, except, I suppose, in desert climates. It likes to grow along streams but can be found in areas far from water. Be wary of its location. Parks especially, but also private areas, are often sprayed with noxious chemicals in a rather unsuccessful effort to contain knotweed’s spread. I chose an area on a hillside away from roads, pedestrians, and dogs. Before using the stalks I removed the leaves, rinsed the stalks with hot water, washed them with detergent and rinsed once more.
The tart flavor of knotweed suggested making a creamy base and adding a complementary ingredient such as a savory herb. The base was easy, the common combination of sour cream and mayo. Adding oregano left me cold; coriander leaves were somewhat more interesting but not wonderful, peppermint was awful but garden mint was a winner. Ingredients 1/2 cup sour cream 1/2 cup mayonnaise 1 1/2 teaspoons finely chopped mint leaves 1/4 cup knotweed stems, peeled and cut into 1/4 inch slices Salt and pepper to taste Preparation
Mix together the sour cream, mayo, and mint. Stir in the knotweed slices, using a few for garnish. Serve with sesame crackers.
What vegetable can’t lend its flavor to soup? Soup is a common use of knotweed. Most recipes use water and/or chicken broth as a base. I tried chicken broth but found the resulting soup not terribly flavorful or interesting. Using beef bone broth was a different story, as was adding sage and celery. The result was an interesting soup of substantial taste with mild acidity. Ingredients 2 tablespoons olive oil 2 tablespoons unsalted butter 1 small onion, chopped 1 clove garlic, peeled and smashed 1/4 cup celery 3 tablespoons chopped sage 4 cups beef bone broth Salt and pepper to taste 8 ounces knotweed stems, thinly sliced and peeled Pansies for garnish Preparation
1. Heat olive oil and butter in large sauce pan. Sauté the onion, garlic, celery and sage for
about 5 minutes.
2. Add beef bone broth, bring to a boil and simmer for 15 minutes.
3. Add knotweed slices and simmer for 10 minutes.
4. Process until smooth.
5. Pour into individual bowls. Garnish each with 1 pansy.
This is a popular use and many recipes employ cider vinegar. As knotweed’s lemony flavor reminded me of the taste that I love to pair with raspberry, I tried raspberry balsamic vinegar and added a bit of spice with ginger. The result? Delightful! Perfect in a salad of spring lettuce. Ingredients 1 cup raspberry balsamic vinegar 1 cup water 1 tablespoon sea salt 2 1/2 tablespoons sugar 1 large shallot, chopped 3 1/4-inch slices fresh ginger 1 1/2 cups knotweed stems, thinly sliced and peeled Preparation
1. Bring to a boil and then simmer for 15 minutes all ingredients except the knotweed.
2. Add knotweed slices and simmer for 10 minutes. Cool. Discard the liquid. Refrigerate, and
use as you would any pickle. This pickle is excellent in salads and sandwiches.