Horseradish is a long white root with a strong hot flavor. It is usually available grated and preserved in vinegar, but can be fresh or dried. When horseradish is used fresh, the scent is produced when it is grated. The grating damages the root releasing chemicals that combine and produce the pungent smell. The smell does not last long, only ten to twenty minutes. This instability can be slowed by mixing the grated horseradish with something sour. Sour apples, lemon juice or vinegar have been used to preserve the flavor and aroma. Heat also destroys the aroma, and for this reason horseradish is often served cold.

1. Kingdom: Plantae
2. Division: Magnoliophyta
3. Class: Magnoliopsida
4. Order: Brassicales
5. Family: Brassicaceae
6. Genus: Armoracia
7. Species: Armoracia rusticana

Horseradish is native to the Mediterranean, but by the 16th century was growing wild as far north as Britain. It was known in Egypt in 1500 BC, and was depicted in a surviving mural in Pompeii. In Jewish culture it is traditionally used during Passover; the bitterness of the horseradish is a reminder of Egyptian oppression.