Cooking

Fill a pot with very cold water, add a couple of trays of ice and set it aside. 

Fill another pot with water up to 3-4” from the top. Add ¼ cup of salt for each gallon of water, and bring to a rolling boil. 

Drop the crabs into the boiling water one at a time, taking care not to overcrowd the pot. Each crab should move freely about in the water with the boiling action. If you have a lot of crabs, cook them in batches.
Once the crabs have been added and the water stops boiling, cover the pot. 
Return it to a boil, and continue to cook for 12-15 minutes.
When the crabs begin to float to the surface of the water, cook for another 2-3 minutes.
Remove the crabs from the boiling water with tongs and plunge them immediately into the pot of ice water to halt the cooking process and prevent shrinkage and drying of the meat.

Cooling and Storage
Cool the cooked crabs in the ice water for 3-4 minutes.
Remove them from the water and drain them.
You can let them cool further if they're still too warm to handle comfortably with your fingers.
It's all right to begin picking out the meat at any time after removal from the ice water. 
Put any unused whole cooked crabs into plastic sealable food storage bags.
They'll keep in the refrigerator for up to a week.

Photo by FomaA, Adobe Stock