In the culinary arts, horseradish is a condiment made from the large, white root of the horseradish plant, which is in the same family as mustard and wasabi.
Making Prepared Horseradish
Horseradish has a pungent, biting flavor and can actually burn the sinuses. It's prepared by peeling the root and then grating it and mixing it with vinegar. In this simple form, prepared horseradish can be used as a condiment, as an ingredient in cocktails, salad dressings and much more.
But since it's not always possible to get fresh horseradish root (and how much of it can you really use?), you can also make prepared horseradish using horseradish powder.
Horseradish powder is a spice made by drying the root and then grinding it into a powder. Making prepared horseradish from the powder is simply a matter of combining it with water and vinegar or lemon juice.
But as with all powdered spices, it'll start to lose its oomph in a few months. Some grocery stores have bulk spice sections where you can purchase as little or as much of a spice as you need. So buy in small amounts so that it stays fresh.
Uses for Horseradish
Grated horseradish root will quickly turn bitter unless it is mixed with vinegar, but when prepared in this way horseradish can be stored in the refrigerator for several months.
Note that prepared horseradish is not the same as horseradish sauce. Horseradish sauce is prepared horseradish that has had cream, sour cream or mayonnaise added, which makes it milder and creamier. Horseradish sauce is frequently served with roasted prime rib, which is one of the most luxurious beef roasts in the universe.