鮭のいずし（青森）

English Version

Features of Salmon Izushi (Aomori)

A “fermented sushi” that brightens winters in North Ōu

Izushi is a northern Japanese style of fermented sushi made by layering salted fish with rice, rice malt (koji), vinegar, and vegetables for a short fermentation. In Aomori it’s prepared with autumn–winter salmon, uniting clean acidity, koji-derived sweetness, and kombu umami.

Koji × vinegar for safety and freshness

Koji enzymes gently tenderize the flesh while lactic fermentation deepens savor. Vinegar and low temperatures suppress unwanted microbes, yielding a quick-matured style ready in a few days.

Vegetables and kombu add aroma and texture

Daikon, carrot, ginger, shredded kombu, and red chili are classics. A small addition of thin-sliced apple lends a refreshing Aomori touch (optional).

Recipe

Ingredients (easy batch; yields ~1.2–1.5 kg finished)

• Fresh salmon (sashimi-grade; skin & bones removed) … 500 g
• Salt … 5% of salmon (25 g) <for pre-salting>
• Cooked rice … 320 g (cooled to room temperature)
• Rice koji (fresh or dried) … 150 g (crumble by hand)
• Rice vinegar … 150 ml
• Sugar … 40–60 g (to taste)
• Sake … 2 tbsp
• Daikon … 200 g (thin half-moons; lightly salted and squeezed)
• Carrot … 80 g (thin matchsticks)
• Ginger … 10 g (fine matchsticks)
• Kombu … 10 g (finely shredded)
• Dried red chili … 1 (thinly sliced)
• (Optional) Apple … 1/4 (thinly sliced)

Hygiene & Safety Prep (Important)

• Freeze salmon at −20 °C for 24+ hours, then thaw in the fridge before use (parasite control).
• Sterilize containers and drop-lids by boiling water or alcohol; use gloves and clean tools.
• Keep all stages (packing → maturation) at 5–8 °C.

Instructions

1. Pre-salt: Slice salmon on a bias into ~1 cm pieces. Rub evenly with 5% salt and refrigerate for 6–12 hours. Wipe off exuded liquid, rinse quickly with a splash of vinegar, and pat completely dry.
2. Make the “bed”: In a bowl, crumble rice + koji, then mix in vinegar, sugar, and sake. Aim for a “slightly sweet–tart” taste.
3. Prep vegetables: Lightly salt daikon 10 minutes and squeeze. Leave carrot and ginger as is; shred kombu; slice chili.
4. Layer: In a sterilized container, build layers: a little kombu → koji–rice bed → salmon → vegetables → bed … Finish with a top layer of bed; dot with chili here and there.
5. Weight: Press on plastic wrap to contact the surface, add a drop-lid and a light weight (about 0.3–0.5× the contents).
6. Mature: Refrigerate at 5–8 °C for 3–5 days. Flip once daily for even curing. When acidity has rounded and aroma blooms, it’s ready.
7. Serve: Drain lightly and plate. Store leftovers airtight in the fridge and enjoy within 2–3 days for best flavor.

Chef’s Tips

• Do not skimp on salt and vinegar—they’re key to safety and brightness. Adjust sweetness with sugar.
• More koji speeds softening; if flavor gets too intense, increase rice to rebalance.
• If you notice off-odors, unusual froth, or mold colors (black/green/pink), discard the batch.

Nutritional Value (per serving, ~100 g)

• Calories: ~120–180 kcal
• Protein: 10–14 g
• Fat: 5–9 g (EPA/DHA from salmon)
• Carbohydrates: 8–14 g (from rice, koji, sugar)

Supplying quality protein and n-3 fatty acids, its fermentation-enhanced umami gives high satisfaction in modest portions.

History

Winter preservation and the “quick-mature” tradition

Harnessing wintry low temperatures, households prepared it in winter to enjoy from New Year through the cold season. Combining rice, koji, and kombu reflects influences attributed to Kitamae-bune trade.

A taste handed down by each household

Ingredient choices, sweet–sour balance, and koji ratio are matters of family know-how. Local touches in Aomori include adding kazunoko or a little apple for fragrance.