Grated horseradish in a glass jar.
What Is Horseradish And Why Is It So Hot?
By Julia Mullaney
Horseradish is derived from the horseradish plant, and it tastes like wasabi or mustard because all three are related. They’re all members of the plant family Brassicaceae.
When the root of the horseradish plant is ground up, certain oils are activated, unleashing the hot flavor. The plant actually activates this flavor as a defense mechanism.
This plant root, which loves the sunshine, is turned into a condiment by being grated and added to a jar with other elements, such as vinegar and salt.
When grated, horseradish releases a chemical known as allyl isothiocyanate, which can clear out even the stuffiest sinuses.
Horseradish gets its spice from that chemical element within the root, but it didn't evolve for human consumption. The flavor is to keep bugs away; it’s a form of protecting itself.