The meat should be softer than fresh fish. If it is rotten, it means the thawing method is wrong.

Proper defrosting: the temperature should be low and the time should be short. The suitable temperature for thawing frozen food is 5 to 15°C. It can be thawed in natural air at about 15℃, or it can be thawed by spraying with tap water at about 15℃. It can be thawed in running water at about 10℃. Do not soak slowly in still water, as this will cause the recovery of microbial and enzyme activity. Cause food to spoil. It is even more forbidden to thaw in hot water, because the tissue structure of frozen food has been damaged. For example, soaking in hot water will accelerate the deterioration of surface proteins and the loss of nutrients, affecting the taste and nutritional value of the food. If you don't have enough time, you can shorten the thawing time by cutting the frozen food into small pieces.