Yuzu Koshō (柚子胡椒, yuzu chili paste)

Ingredients

Equipment Needed

• •Fine grater, ideally an oroshigane, or a Microplane
• •Suribachi and surikogi, or a mortar and pestle
• •Kitchen scale
• •Clean small glass jar with tight lid
• •Gloves for handling chilies

Instructions

1. 1

   Wash and dry

   Wash the yuzu and chilies, then dry them very well. Water left on the fruit thins the paste and shortens its keeping life, so don't hurry this small plain step. The yuzu should feel firm and smell sharp even before you grate it.

2. 2

   Grate the peel

   Grate only the green outer peel from the yuzu, stopping before you reach the white pith. The colored peel holds the fragrant oil; the pith brings bitterness and no help. Weigh the grated peel, because the salt should follow the ingredient, not a guess.

3. 3

   Prepare the chilies

   Remove the chili stems and chop the chilies finely. Keep the seeds if you want the Kyushu heat to stand up straight, or scrape out some seeds for a quieter paste. Wear gloves if your skin is sensitive, then wash the board and knife well.

4. 4

   Weigh the salt

   Add the weight of the yuzu peel and chopped chilies together, then measure fine sea salt at about 20 percent of that weight. This amount tastes strong at first, but it preserves the paste and gives the citrus and chili time to become one flavor.

   For 25g peel and 25g chili, use 10g salt. A scale is the cleanest tool here; spoons make salt too vague.
5. 5

   Pound the paste

   Put the peel, chilies, and salt in a suribachi and pound with the surikogi until the mixture turns moist, coarse, and glossy. You are not making it pretty for the jar. You are breaking the peel cells so the yuzu oil meets the chili and salt.

   No suribachi? Use a mortar and pestle, or pulse briefly in a small food processor, scraping often. Stop before it becomes watery.
6. 6

   Jar and age

   Pack the paste into a clean small jar, pressing out air pockets, and cover tightly. Refrigerate for at least 2 weeks before using if you can bear it. The rest softens the raw bite, rounds the salt, and lets the fragrance settle through the whole paste.

7. 7

   Serve sparingly

   Use a pea-sized dab beside nabe, grilled fish, chicken, tofu, or udon. Stir it into broth at the table or touch it to a bite as you eat. Too much will bully the dish, and this cuisine has enough manners not to do that.

Chef Tips

• •Make this when green yuzu is at its prime. If you only have yellow yuzu, make the red style with red chilies instead of pretending it is the same dish.
• •Don't grate into the pith. One careless extra stroke can turn a bright paste bitter, and bitterness lingers longer than heat.
• •Use fine sea salt, not coarse crystals, so it dissolves quickly into the wet peel and chili. The seasoning should disappear into the paste, not crunch under the teeth.
• •Keep the jar small and the surface clean. Each time you use it, take what you need with a clean spoon and close the jar again.

Advance Preparation

• •Yuzu koshō is best made 2 to 4 weeks before serving, when the salt has rounded and the citrus and chili have settled together.
• •Stored refrigerated in a clean jar, it keeps about 2 months. Freeze small portions for longer keeping, then thaw only what you need.

Frequently Asked Questions

Nutrition Information

1 serving (about 8g)