A cold-weather herb related to the mustard family, horseradish matures in late summer or early autumn and is harvested in autumn or winter. The gnarly, twisted root is usually grated and used to add a healthy dose of heat to meat or fish dishes or sauces. Freshly grated horseradish is usually stored in the refrigerator, where it keeps for a few weeks. However, horseradish is easy to freeze and the storage time is much longer -- usually about six months.
Rinse horseradish roots thoroughly to remove sand and grit, then peel the root with a paring knife or potato peeler. Cut the peeled root into small cubes.
Chill the blades of a food processor or blender in a bowl of ice water or crushed ice before you begin because horseradish generates heat. Place the horseradish in the blender or food processor container and grind it to the desired consistency.
Add a small amount of white vinegar to the horseradish to stop the natural enzyme activity and moderate the heat. As a general rule, use about 2 to 3 teaspoons of vinegar for each cup of horseradish. If you want blazing hot horseradish, add the vinegar as soon as you finish grinding the root. For milder horseradish, wait about three minutes before adding the vinegar.
Cover a baking sheet with plastic wrap. Spoon the horseradish onto the plastic in serving-size heaps. Place the baking sheet in the freezer.
Remove the baking sheet from the freezer when the horseradish is frozen solid. Transfer the frozen horseradish into a plastic freezer containers or resealable plastic bag, then return it to the freezer.
An ice cube tray works well for freezing horseradish in uniform, serving-size pieces. Freeze the horseradish in the ice cube tray, then transfer the frozen cubes to a freezer container.
Never add apple cider vinegar to grated horseradish because it will cause the horseradish to turn brown quickly.
Food keeps best in a freezer set to zero degrees Fahrenheit. If you aren't sure about your freezer's temperature, test it occasionally with a freezer thermometer.
Always work with horseradish in a well-ventilated room, because the pungent fumes are strong enough to sting your nose and eyes.