Only use Urume sardines that are sold specifically for raw consumption and have been properly processed as candidates for sushi toppings. Do not assume that freezing alone makes those which cannot be confirmed for raw use safe; instead, they should be reserved for cooked dishes.
What Freezing Can and Cannot Solve
The freezing guidelines provided by the Ministry of Health, Labour and Welfare mainly address parasites such as Anisakis. However, freezing does not kill all bacteria. Poor temperature control or hygiene before freezing means safety cannot be guaranteed even after freezing.
Therefore, you cannot conclude “Urume sardines frozen at -20°C for 24 hours are safe to eat raw” regardless of the source.
Checks Before Making Sushi
- Is it sold as safe for raw consumption?
- Were the innards and exuded fluids properly managed at the time of purchase?
- If frozen, can the temperature and duration of freezing be recorded?
- Are there no abnormalities in appearance or smell?
Vinegar, ginger, and green onion are flavoring ingredients. They do not substitute for heat treatment or proper freezing to prevent food poisoning or parasites.
When in Doubt, Cook It
If raw-use labeling or the management status is unclear, switch to cooking methods such as grilling or simmering until thoroughly heated in the center. Prioritize not eating or heating the fish over the reluctance to “waste” it.
