Horseradish (Armoracia rusticanais) is a perennial vegetable grown in Pennsylvania. While the leaves are edible, it is grown for its pungent roots. Generally, horseradish is planted in early spring and harvested in late fall after a frost sweetens the roots. The roots are prepared and used in savory recipes. Some roots can be stored through the winter to re-plant in the spring. Read https://extension.psu.edu/growing-horseradish for more information on growing horseradish.
After harvesting and scrubbing the horseradish roots until clean, a decision must be made as to what to do with them. The most common use is to make pickled horseradish sauce. When the roots are intact, they have little aroma. But, as soon as they are grated or ground, which you must do to use horseradish for culinary purposes, a compound is released that will irritate your eyes, sinuses and mucous membranes. This compound is allyl isothiocyanate, a mustard-like oil, and it is also what produces the heat and pungency in horseradish. It is important that you grate or grind horseradish roots in a well-ventilated area and, depending on your sensitivity, even perhaps wear goggles and a mask.
The addition of vinegar to the ground horseradish neutralizes the enzymatic process of this compound. Vinegar stabilizes the flavor. The longer you wait to add the vinegar, the hotter the results will be. But don’t wait longer than a few minutes, or the resulting flavor will be bitter. You may choose to grate the roots directly into a bowl of vinegar for a milder flavor. Use white vinegar with a 5% acidity level. Cider vinegar will lead to discoloration sooner.
Pickled horseradish sauce is also called prepared horseradish or horseradish relish (see following recipe). It is simply grated horseradish root, white vinegar, a little salt, and a bit of ascorbic acid (vitamin C), which helps keep the relish from browning. There is no research-based recipe for canning this relish to make it shelf-stable at room temperature. It is stored in the refrigerator. Prepared horseradish is most often used as an accompaniment to roast beef and an ingredient in seafood cocktail sauce or Bloody Mary drinks. It can also be added to sour cream, mayonnaise, and other savory recipes like Sally Longyear’s Caesar dressing (see following recipe).
Once prepared, horseradish loses its flavor in a matter of weeks. Therefore, with an abundance of roots, prepare what you will use in a two-month period and store the remaining roots for later use. Horseradish roots store well in a cool, dark, humid location. Light turns the roots green. Green roots are subpar. Store in a refrigerator at 32 F to 40 F in dark, perforated plastic bags for up to three months. If you are lucky enough to have a cold root cellar, use it for horseradish roots. Ideally, bundle the roots, store them in damp sand, and do not expose them to light. Held in ideal conditions at 30 F to 32 F and at humidity between 90-95%, the roots can last for 10 to 12 months or until the next harvest.
You can also dry horseradish. After cleaning and peeling the roots, simply grate the roots coarsely or slice them into 1/4-inch rings. Although a vegetable, no blanching is required. Spread horseradish in single layers onto trays and dry in a dehydrator, at a temperature of 140 F, for six to 10 hours until completely brittle. You can choose to powder the dried root chips or leave as chips. When cool, store in an airtight container in a cool, dark, dry place and use within a year. A dehydrator should usually be used indoors in a dry, well-ventilated room, but horseradish is so pungent that it is advised to place the dehydrator in a garage or covered outdoor space like a porch. To use, mix a little water with a measure of the dried horseradish before adding it to sauces, dressings and other recipes.
Pickled Horseradish Sauce (aka Horseradish Relish or Prepared Horseradish)
- 2 cups (3/4 pound) freshly grated horseradish
- 1 cup white vinegar (5%)
- 1/2 teaspoon canning or pickling salt
- 1/4 teaspoon powdered ascorbic acid
- The recipe yields about two half-pints.
The pungency of fresh horseradish fades within one to two months, even when refrigerated. Therefore, make only small quantities at a time.
Start with clean countertops and utensils. Wash hands for 20 seconds and dry with a single-use paper towel.
Wash and scrub horseradish roots thoroughly with a clean vegetable brush and peel off the brown outer skin. The peeled roots may be grated in a food processor or cut into small cubes and put through a food grinder. Combine ingredients and then put them into sterile jars, leaving 1/4-inch headspace. Seal jars tightly and store them in a refrigerator.
Sally Longyear’s Caesar Dressing
- 1/2 cup olive oil
- 1/2 cup Parmesan cheese
- 2 to 4 cloves garlic
- Juice of 1 or 2 lemons
- 1 teaspoon Worcestershire sauce
- 1 teaspoon prepared horseradish
- 1 can (2 ounces) anchovies in oil (optional)
Start with clean counters and utensils. Wash hands for 20 seconds and dry with a single-use paper towel.
Whip all ingredients together in a blender or food processor. Pour over a large bed of washed, torn Romaine lettuce and croutons. Mix and let stand for five minutes before eating.