Choose good roots. Look for firm, heavy horseradish with smooth skin and no soft spots. Fresher roots mean stronger flavor.

Prep your space. Work in a well-ventilated area. Horseradish fumes can be intense—open a window, and consider wearing eye protection if you’re sensitive.

Peel and trim. Use a vegetable peeler to remove the tough outer skin. Cut off dry or woody ends.

Grate or slice thin. A box grater or food processor works well. Smaller pieces dry faster and more evenly. Aim for fine shreds or very thin slices.

Optional quick soak. Toss the grated horseradish with 1–2 tablespoons of vinegar and a squeeze of lemon juice per pound. This can help manage browning and slightly stabilize flavor. Drain well before drying.

Load the dehydrator. Spread the horseradish in a thin, even layer on lined dehydrator trays. Avoid clumps, which dry unevenly.

Dehydrate low and slow. Set to 95–115°F (35–46°C). Dry for 6–10 hours, stirring once or twice. It’s done when completely brittle, not bendy.

Oven method (if no dehydrator). Set the oven to its lowest temp (ideally 170–200°F/75–93°C). Spread on parchment-lined sheets, prop the door open slightly for airflow, and dry for 2–4 hours, checking often.

Cool completely. Let the dried horseradish sit at room temp for 15–20 minutes. Trapped heat can cause condensation in storage jars.

Grind to powder. Use a spice grinder, coffee grinder dedicated to spices, or a high-speed blender. Work in short pulses until fine. Sift and regrind larger bits if needed.

Optional seasoning. For a ready-to-use blend, stir in a small amount of kosher salt (start with 1/4 teaspoon per tablespoon of powder). Keep some plain for recipes that already include salt.

Jar and label. Store in an airtight container, ideally a glass jar with a tight lid. Label with the date and note if salted.