Combine the salt, sugar and 1 gallon water in an 8-quart pot. Bring to a slow boil and cook until thoroughly mixed together and no solids are left at the bottom of the pot. Stir in the molasses, pepper flakes, vinegar, allspice, bay leaves and cloves, then remove from the heat and let the brine cool completely.
Transfer to a 16-quart container and add 2 gallons of cold water. Mix until well combined.