As a tentative guideline for practice, start with 5 to 10 minutes when salting tuna. This time varies with the thickness of the fish and the amount of salt, so do not fix the time rigidly at 15 to 20 minutes.
How to Determine Timing
Thin slices require shorter salting times, while thicker portions (called “saku” — blocks of tuna used for slicing sashimi) need a slightly longer duration. Even if the weight is the same, the surface area differs, which affects salt absorption. Therefore, record not only the time but also the thickness and amount of salt.
Initially, sprinkle salt thinly on one side only, then after 5 minutes, check the surface moisture and flavor. Adjust by 1 to 2 minutes accordingly in subsequent trials, finishing before the saltiness becomes too strong.
Avoid Salting for Too Long
Leaving salt on for an extended period draws out too much surface moisture and alters the texture and salt flavor of the flesh. After salting, inspect the surface and proceed to the next step while managing refrigeration.
Result of Leaving it for Half a Day
In this trial, after sprinkling salt on the tuna, wrapping it in paper, and refrigerating it for half a day, the moisture was moderately drawn out, the flavor intensified, and the umami seemed enhanced. This created a distinct difference compared to eating immediately after salting.
However, this is an observation from a single experience and not a universal rule for salting duration or a guarantee of raw consumption safety. Results will vary depending on fish thickness, amount of salt, and the condition at purchase. Always prioritize expiration dates and cold storage management.
Important Notes
The salting time does not guarantee the safety of the fish. Use tuna managed and labeled for raw consumption. Do not use if there are abnormalities in smell, color, or temperature.
What to Record Next
- Thickness and weight of the tuna block (saku)
- Weight of the salt used
- Condition of the surface after 5 minutes
- Saltiness and texture when eaten
