Horseradish, Armoracia rusticana, is a thick root vegetable and part of the Brassicaceae family along with broccoli, cabbage, radishes, mustard, and wasabi (often called Japanese horseradish). It can be grown as an annual or perennial and is commonly used in American and European cuisine as a spice or part of soups, sauces, and spreads.
Horseradish is believed to have originated in Europe, where it was lauded for its medicinal properties through the centuries. In the United States, in a region of the Mississippi River floodplain called the ‘American Bottoms’ in southwestern Illinois, is where the vast majority of North America’s horseradish supply is grown.
Other states grow the root in lesser quantities, including California, New Jersey, Oregon, and Wisconsin. Canada also grows horseradish, and it is still cultivated in a number of European countries.
While the sturdy, tapered root is harvested for culinary use, the foliage has little commercial value today, though the leaves were used with the root back in the Middle Ages. Top quality roots are white, straight, and free of speckling or discoloration with a diameter close to 2 inches, weighing in at a couple pounds each. Horseradish root is most often ground or shredded, but can be dehydrated to lock in its pungent flavor.
Types & Varieties
Horseradish is a prized addition to many types of cuisine. The root is bought and sold fresh in small amounts (generally from a grower to restaurant or specialty seller) or sold in larger quantities for processing into condiments.
Varieties are based on the type of root and include Common (also called Maliner Kren), Czech (a newer cultivar), Bohemian (including Sass and Swiss), Big Top Western, Variegata, and Wild Root. When the root is crushed, shaved, shredded, or ground, it releases mustard oil, which is responsible for its ‘hot’ flavor and sharp, penetrating odor. Once roots are exposed to air, they will turn brown and lose intensity. Cooking will reduce pungency as well.
‘Prepared horseradish’ is the ground root mixed with vinegar to stabilize and preserve its flavor. The concoction is particularly popular in the United Kingdom, while various dressings and mayonnaise containing grated horseradish are sought after in the United States. Mixing with mustard is another centuries-old use, originating in Europe. More recently, due to declining availability of wasabi plants, horseradish (a close relative) has become a substitute in sushi dishes.