After one day, strain the brine into a pot (and put the crabs back in the fridge). Bring the brine to a boil over medium heat, and boil for 3 to 4 minutes. Wait for the brine to completely cool, and then pour it back over the crabs. You can skip this process, but it enhances the flavor of the brine and helps the crabs to last longer.
The crab infused leftover brine can be re-used to marinate meat or as a dipping or seasoning sauce. Boil it for a few minutes and cool before saving it in the fridge for later use.