FDA guidelines (the lower the temperature, the less time they need to stay frozen; for home freezer temperature, 7 days or more is safe). In fact, flash-freezing is the method "sushi cut" suppliers use to make the fish safe for raw consumption. Feel free to freeze your own Costco salmon and make spicy salmon rolls!
*Note: while freezing kills parasites, it does not eliminate bacteria. If you want to be extra cautious, curing your fish in salt water can help killing bacteria. But as you would often see in the fine prints of many steakhouse menus, there is always bacterial risk associated with eating undercooked meat, fish, or egg. Eating raw will always take a little leap of faith. Just no more here than you would be, buying from takeout or grocery. The label "sushi grade" is largely a marketing term, that is not regulated beyond the temperature requirement set forth in the FDA guideline.
Ideally you want to use sushi rice for the rolls. Rinse the rice and discard the water for about 3 times, to remove surface starch, and leave the rest to your rice cooker. If you don't have a rice cooker, or the patience to wait for rice to cook, I find premade short grain rice to be a perfectly acceptable substitute, for people who are consuming spicy tuna rolls at least. Sure it'll make a sushi chef cringe, but it'll make your roommates very happy if you offer them some.To Assemble:
- 2 tbsp rice vinegar
- 1 tbsp sugar
- 1/2 tsp salt
- Dice tuna into preferred size. Mix with rest of the fillings ingredients.
- Season cooked rice with sushi vinegar. About 1tbsp vinegar for each cup of rice.
- Spread rice on seaweed sheet, sprinkle with sesame
- Cover with saran wrap, and flip the seaweed sheet.
- Fill with tuna, and roll using the saran wrap, if you don't have a bamboo roller.
- Cut into 6~8 pieces and serve.
- If making hand rolls: cut seaweed sheet into squares. fill with rice and tuna, and roll along the diagonal.
Check out step-by-step video on my YouTube Channel!