Real Food Encyclopedia | Mustard Greens
Mustard greens suffer from an inferiority complex — they haven’t enjoyed a culinary renaissance like kale; they don’t have the romantic Italian provenance of broccoli rabe, nor the Southern panache of collard greens. But they certainly shouldn’t be ignored: their peppery bite is perfect in summer salads, awesome when tossed in with legumes like lentils and delicious when sautéed like spinach.
Mustard has been cultivated for centuries across Asia and Europe for both its edible seeds, ground and made into mustard (the condiment) or pressed for their oil, along with its leaves (and even stems). There are several different types of mustard, some of which are native to central Asia – probably somewhere in the Himalayan region – and some that are native to Europe. Food historian Alan Davidson notes that mustard seeds have been found in ancient Greek archeological sites; ancient Greek historian Herodotus wrote of their cultivation as early as the 5th century BCE.
In Europe, mustard plants have primarily been utilized for their seeds to make mustard (which Davidson notes has been important there for centuries because it is one of the few spices that can be locally grown), though leaf mustard was, and is, also eaten. (Apparently, in Medieval Europe, courts and monasteries often employed a person, called a mustardarius, whose sole job was to oversee the growing and making of mustard.) China is one of the major secondary sources of genetic variation of the mustard plant, according to botanists, centered primarily around the Sichuan region. (This basically means that mustard has been cultivated there for a very, very long time.)
Fun Facts about Mustard Greens:
- Mustard plants have been successfully used in phytoremediation, the use of plants to remove toxic substances (like heavy metals) from the soil.
- Mustard greens are increasingly used as a winter crop cover. They are cold hardy, grow rapidly and even have natural chemical compounds that may help combat soil-borne diseases and weeds.
- Mustard oil, used extensively in some South Asian cuisines, is banned in the US for culinary purposes (though it is legal as a massage oil). The FDA’s reason for the ban is that the erucic acid found in the oil causes “nutritional deficiencies” and “cardiac lesions” in test animals, although there is some evidence on the pro-mustard oil side that bringing the oil to the smoke point greatly reduces some of these negative effects.
What to Look for When Buying Mustard Greens
Leaf mustard comes in an array of shapes and sizes. At many markets, the ruffled-edge, bright green, large-leaved mustard called Southern Giant is probably the most common, but mustard greens vary from small leaved to large; from yellow-green to purple to deep, dark green. Some varieties, like Japanese mustard (mizuna), have thin, deeply serrated, small-ish leaves with thin stems; others, like Red Giant, have softly rounded, very large leaves with very thick stems.
For all types of leaf mustard, look for perky greens with no wilting and no mushy or black spots. Also steer clear of mustard greens with yellowing or browned leaves.
Sustainability of Mustard Greens
According to GMO Compass, there have been several field trials of genetically modified (GM) mustard plants (of various species/sub-species) in several different countries, including in the US, but none have yet become commercially viable. The good news: mustard greens don’t appear on the Environmental Working Group’s Guide to Pesticides in Produce. They aren’t bothered much by pests, but if you are concerned about pesticides, do check with your local mustard farmer about his/her growing practices to be sure that pesticides weren’t used.
Mustard Greens Seasonality
Mustard greens are primarily a cool season veggie and are at their peak in late spring to early summer. Hot weather causes the plants to bolt and their greens to turn unpleasantly bitter. A fall crop is often planted because mustard is frost-resistant and easily overwinters in temperate areas.
Eating Mustard Greens
Storing Fresh Mustard Greens
Wrapped in a barely damp paper towel and stuck in an open zip-top bag in the crisper drawer of your fridge, mustard greens will keep for 3 to 4 days.
Cooking with Mustard Greens
Mustard greens can be steamed, tossed into soup, sautéed (like spinach or Swiss chard), stir-fried or braised. Sub mustard greens for spinach or Swiss chard in recipes and see what you think – their peppery flavor is much reduced through cooking. The greens pair deliciously with beans (especially white beans and lentils), pork (especially ham hocks), other dark leafy greens (like spinach, collards and turnip greens), tofu, garlic, onions and citrus. Adding fat, salt and a little acid (like vinegar or lemon juice) also cuts the bitterness of bitter leafy green vegetables like mustard greens.
Mustard seeds are used extensively in Indian cuisine, usually fried in oil and added to dishes like Potatoes with Mustard Seeds. They are also, of course, made into mustard (the condiment) – of which there are many, many variations, from course-grained brown to the yellow ballpark mustard ubiquitous in the US (and incidentally traditionally colored yellow with turmeric). Read more about mustard (the condiment) here.
Preserving Mustard Greens
Mustard greens take super well to preservation, especially pickling and lacto-fermentation. In many cuisines, including Indian, Chinese (especially Sichuan), Japanese, Vietnamese and Thai, the greens are pickled and used a condiment, side dish or added to soup. (Some leaf mustard varieties have thickened stems that are also pickled.) Here’s a pickled mustard green recipe from Hunter Angler Gardener Cook and a Vietnamese pickled mustard greens recipe. The greens can also be successfully frozen – here’s a video that details the process.
Mustard Greens Nutrition
Like a lot of greens, mustard is super good for you. One cup has over 500 percent of your daily vitamin K intake, necessary for blood and bone health. The greens are also a great source of vitamin A, vitamin C and folate, and contain decent amounts of calcium and manganese. They even have calcium and protein! And, of course, mustard greens are high in fiber and low in calories.
Mustard seeds have been used for centuries for various ailments. A mustard plaster, wherein mustard seeds are ground up, spread on a cloth and applied to the skin, was traditionally used to treat lung infections and other respiratory problems.
The glucosinolates in mustard greens — the chemical compound that causes the greens’ characteristic bitter bite and is responsible for their natural insect-fighting properties — seems to also be a natural cancer-fighter. High consumption of mustard greens and their Brassica brethren has been linked to reduced risk of certain cancers, including prostate. And one more bonus: according to the horticulturalists over at Purdue University, eating mustard greens “may impart a body odor repellent to mosquitoes.” Fights cancer and mosquitoes – are mustard greens the perfect food?