1tablespoonsoup soy sauceguk ganjang, 국간장 - or use 1/2 teaspoon salt
2teaspoonsfinely gratedjuiced ginger
Put the live crabs in the freezer for an hour or two (longer is fine as well).
Combine all the seasoning ingredients and mix well. The seasoning can be prepared a day or two in advance. It will further develop flavor as it sits.
Plunge the frozen crabs in cold water to thaw. Separate the top shell and remove the gills. Clean the shell part of the crab thoroughly, with a kitchen brush or a toothbrush, under running water.
Break (or cut) the body in half (or quarters). You can cut off the sharp end of each small leg with a pair of kitchen scissors if preferred. Drain well in a colander in the fridge. It’s important to minimize the time that the crabs are out at room temperature.
Combine the crabs and seasoning, and toss to coat well. Spoon some sauce into the top shells. Marinate for a few hours at least or up to a couple of days in the fridge. These spicy crabs are best eaten within a couple of days.
You can add some chopped onion and/or chili pepper to the seasoning sauce. Also, you can add 1 tablespoon of Korean plum syrup (maesil chung, 매실청), or 2 tablespoons of grated pear or apple for some fruity sweetness with a hint of acidity.