Why can you marinate raw fish for 3 days, but you’re supposed to cook it in a day or two after buying it from the grocery store?

Question

I’ve been reviewing recipes for a Japanese black cod recipe. It’s very poopular. Every video I watch has Japanese chefs confidently stating that you need to marinate it in a mixture of sake, mirin, and miso for 3 days before baking it. When you do bake it, it’s for about 20 minutes.

How do people not get sick from this process? Does the sake somehow kill bacteria or something?

Thanks!

In: 3

Answer 1

You need about 70% alcohol by volume to reliably kill bacteria, so the marinade won’t decontaminate your fish, but it will inhibit bacterial growth. Basically it extends that 1-2 day cooking window by at least slowing bacterial growth. It may even kill the bugs, but don’t rely on it. Cooking mostly does that.