Although Japanese mackerel variety is slightly different from that fished in European waters, our common mackerel is perfectly suited. Often disparaged when marinated in vinegar, mackerel flesh has a complex flavor, rich in umami, with iodized and sweet notes when fatty.
The secret to good saba sushi lies in fish perfect freshness, as flesh spoils very quickly. To remedy this, Japanese chefs use shime saba technique, which consists of heavily salting mackerel fillets before marinating them in rice vinegar. To eliminate mackerel parasites, we recommend freezing the whole fish for 48 hours before lifting the fillets, salting them and marinating them in vinegar. Then remove the bones and rub the flesh (not the skin part) with a generous dose of salt, leaving fish to dry for an hour to 90 minutes before rinsing gently in fresh water to remove all the salt. Flesh should be a little firmer, as salt will have removed the excess moisture. Vinegar used will be a mixture of 80% very good rice vinegar and 20% fresh water.
Vinegar should completely cover the fillets. If mackerel fillets are small, they should be marinated in vinegar for just 20 minutes. For large fillets, double the time, i.e. 40 min. Once marinated, fillets should be quickly rinsed in water, then blotted dry. They should then be individually wrapped tightly in greaseproof paper and cling film, and placed into the fridge for 24 hours. Then unwrap them and dry them well with paper towel, before peeling off first layer of skin. Take the mold and moisten each side with vinegar from the marinade to prevent rice from sticking. Place mackerel fillet with skin facing the mould bottom, then add rice and place the part to be pressed on top and press firmly. Slots on mold sides allow you to cut into regular portions before unmolding.
