Onion nettle powder is a savory, umami-rich seasoning made by drying and grinding onion and stinging nettle leaves. It adds a deep, slightly sweet onion flavor with a subtle earthy, herbaceous note, and it’s a fantastic way to preserve a spring harvest or use up extra onions. This homemade powder is more flavorful than store-bought versions, and it’s incredibly simple to make with just two ingredients and a dehydrator or oven.
Ingredients
- 2 large onions (about 1 lb / 450 g total), any variety
- 2 cups (40 g) fresh stinging nettle leaves (see Tips for handling and substitutes)
Instructions
- Prepare the nettles (if using fresh): Wearing thick gloves, trim the leaves from the stems and discard the stems. Rinse the leaves thoroughly under cold water to remove any dirt or insects. Pat dry with a clean towel or use a salad spinner.
- Blanch the nettles: Bring a large pot of salted water to a boil. Add the nettle leaves and blanch for 1 minute. Drain and immediately plunge into a bowl of ice water to stop the cooking. Squeeze out as much water as possible with your hands (wearing gloves is still wise if the leaves are very fresh).
- Slice the onions: Peel the onions and cut them into thin slices, about 1/8-inch (3 mm) thick. You can use a mandoline for even slices, but a sharp knife works fine.
- Dry the ingredients: Spread the onion slices and blanched nettle leaves in a single layer on dehydrator trays lined with parchment paper (or on a baking sheet if using an oven). Set your dehydrator to 125°F (52°C) or your oven to its lowest setting, ideally 170°F (77°C) or “warm.� Dry for 4 to 6 hours, checking every hour, until the onions are brittle and snap easily, and the nettles crumble between your fingers. Rotate trays if needed for even drying.
- Cool completely: Let the dried ingredients cool to room temperature. This prevents condensation and clumping when you grind them.
- Grind to a powder: Working in batches, place the dried onions and nettles in a spice grinder, blender, or food processor. Pulse until you have a fine powder. If the powder isn’t uniform, sift it through a fine-mesh strainer and grind the larger pieces again.
- Store: Transfer the powder to an airtight glass jar. Label with the date. It will keep for up to 6 months in a cool, dark place.
Tips
- Handling nettles: Always wear thick rubber gloves when handling fresh nettles—the tiny hairs sting. Blanching completely neutralizes the sting, so after that step you can handle them safely with bare hands.
- No dehydrator? Use your oven on the lowest setting (usually 170°F/77°C) and prop the door open with a wooden spoon to let moisture escape. Drying time may be slightly longer.
- Substitute for nettles: If you can’t find stinging nettles, use an equal amount of fresh spinach, kale, or arugula. The flavor will be milder, but still delicious. Or skip the greens entirely and make onion powder alone.
- Don’t overheat: High heat can make the powder taste bitter and dull the color. Keep the temperature low and be patient.
Serving Suggestions
Use onion nettle powder as a seasoning for roasted vegetables, mashed potatoes, soups, stews, and grain bowls. It’s excellent in salad dressings, sprinkled over popcorn, or rubbed onto chicken or fish before cooking. You can also mix it into softened butter for a savory compound butter.
Variations
- Garlic-Onion Nettle Powder: Add 4-5 peeled garlic cloves (sliced thinly) to the dehydrator along with the onions and nettles.
- Smoky version: Add 1 teaspoon smoked paprika to the finished powder and shake to combine.
- Spicy kick: Add 1/2 teaspoon cayenne pepper or red pepper flakes to the powder.
Storage and Reheating
Store the powder in an airtight glass jar in a cool, dark cabinet for up to 6 months. It does not need refrigeration. If you notice any clumping or moisture, spread the powder on a baking sheet and dry in a 170°F (77°C) oven for 10 minutes, then cool and re-crumble. Because it’s a dry seasoning, there’s no reheating involved—just add it directly to dishes.
Frequently Asked Questions
Can I use dried nettles instead of fresh? Yes, you can use dried nettle leaves (often sold as tea). Skip the blanching step and simply grind the dried leaves with the dried onions. Reduce the amount to about 1/2 cup (15 g) since dried leaves are more concentrated.
How long does onion nettle powder last? Properly stored in an airtight container away from light and heat, it will keep its best quality for up to 6 months. After that, it may lose potency but will still be safe to use if no moisture gets in.
Can I make this without a dehydrator? Yes, use your oven on the lowest setting (170°F/77°C) with the door ajar. Drying times may vary, but the onions should be brittle and the leaves crumbly before grinding.
Is it safe to eat raw stinging nettles? No, raw nettles sting and can irritate your mouth and throat. Always blanch or cook them before eating. The powder is safe because the blanching step neutralizes the sting.
What can I substitute for stinging nettles? Spinach, kale, or arugula work well. They won’t have the same earthy depth, but they’ll still add a pleasant green note. You can also use parsley or celery leaves.
Can I use this powder as a 1:1 substitute for onion powder? Yes, but expect a slightly more complex flavor. Start with half the amount and adjust to taste, since the nettle adds an herbal note that can be more pronounced.
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