ISO Korean Raw Marinated Crab Recipe
3-4 live crab (top shell removed, cleaned and cut in half)
1/2 cup soy sauce
1 red chili pepper, 1 green chili pepper
2 stalks of green onion
1tsp minced garlic
1/3tsp minced ginger
4Tbsp chili pepper powder
1/2tsp sesame seeds
Combine seasonings and pour over crab. I let it sit for at least a day, then check every day until it's seasoned to my liking. They never lasted long in my fridge either so I can't tell you that :D
MM's sauce is very close to what my wife uses. The main difference is she cooks the sauce (just brings it to a boil, then simmer for fifteen to twenty minutes). She then cools the sauce completely before pouring over the crab.
As to how long it will last - my wife says it depends on how much you "bother" (ope/close) it, but up to a month.
She has also seen it done in Korea with some additional steps that is good for up to a year as long as it remains un-opened.