📝 About This Recipe
Originating from the Kyushu region of Japan, Yuzukosho is a transformational condiment that marries the floral, high-toned acidity of yuzu citrus with the sharp, creeping heat of green chilies. This fermented paste undergoes a slow maturation process, where salt mellows the heat and develops a deep, savory complexity known as 'shumi.' It is a vibrant, electric addition to any kitchen, capable of brightening everything from fatty sashimi to grilled ribeye with just a tiny smear.
🥗 Ingredients
The Citrus Component
- 10-12 pieces Fresh Yuzu Fruit (Firm, bright yellow or green skins with no soft spots)
- 2-3 tablespoons Fresh Yuzu Juice (Reserved from the fruit after zesting)
The Heat Component
- 100 grams Green Thai Bird's Eye Chilies (Stems removed; for a milder paste, use Serrano)
- 50 grams Green Jalapeño Peppers (To add body and a grassy depth)
The Fermentation Essentials
- 10-12% of total weight Fine Sea Salt (Crucial for safety and flavor development; do not use iodized salt)
- 1 teaspoon Rice Vinegar (Optional, to help kickstart acidity)
- 1/2 teaspoon Kombu Powder (For an extra layer of natural MSG/umami)
👨🍳 Instructions
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1
Thoroughly wash the yuzu fruit and chilies in cold water. Pat them completely dry with a clean lint-free towel; moisture is the enemy of a successful ferment.
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2
Using a microplane or a fine grater, zest the yuzu fruit. Be careful to only take the fragrant outer zest (flavedo) and avoid the bitter white pith (albedo) underneath.
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3
Place a clean bowl on a digital scale and tare it. Collect all the yuzu zest in the bowl and record the weight in grams.
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4
Prepare the chilies by removing the stems. Slice them lengthwise and scrape out the seeds and white membranes if you prefer a milder paste; keep them for traditional heat.
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5
Finely mince the chilies by hand or pulse them in a food processor until they reach a consistency similar to the zest. Do not over-process into a liquid puree.
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6
Add the processed chilies to the bowl with the yuzu zest. Note the new combined weight.
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7
Calculate the salt: Multiply the total weight of the zest and chilies by 0.10 (for 10% salt). Weigh out this exact amount of sea salt.
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8
Add the salt, kombu powder, and 2 tablespoons of yuzu juice to the mixture. Use a mortar and pestle or a sturdy spoon to grind the ingredients together until a cohesive paste forms.
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9
Transfer the paste into a sterilized glass jar. Press down firmly with a spoon to remove any air pockets, which can encourage spoilage.
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10
Wipe the inside rim of the jar clean. Cover the surface of the paste directly with a small piece of plastic wrap, then seal the jar tightly.
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11
Place the jar in a cool, dark place (like a pantry) for 7 to 14 days. This allows the flavors to meld and the harshness of the raw chili to soften.
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12
Taste the paste after one week. It should be salty, spicy, and incredibly aromatic. Once the desired flavor is reached, move the jar to the refrigerator to slow the fermentation.
💡 Chef's Tips
Always wear gloves when handling a large volume of Thai chilies to avoid skin irritation. If you cannot find fresh yuzu, a combination of 2 parts lemon zest and 1 part lime zest is a respectable substitute. Ensure all equipment—bowls, graters, and jars—are sterilized with boiling water before use to prevent bad bacteria growth. For a smoother, commercial-style texture, you can run the finished fermented paste through a high-speed blender for 30 seconds. Remember that the salt content is high by design; this is a seasoning meant to be used in small quantities, not a dip.
🍽️ Serving Suggestions
Whisk a teaspoon into a classic vinaigrette for a bright, spicy salad dressing. Serve a small dollop alongside grilled yakitori or a seared New York Strip steak. Stir into a bowl of hot Tonkotsu or Shio ramen to cut through the richness of the broth. Mix with softened unsalted butter to create a 'Yuzukosho Butter' for finishing steamed vegetables or seafood. Pair with a crisp, cold Junmai Ginjo sake or a dry Riesling to complement the citrus notes.