Heat water and 1 tablespoon sea salt together in a pot over medium heat until salt is dissolved and brine is heated, about 5 minutes. Remove pot from heat and cool brine to 70 degrees F (21 degrees C).
Mix beans, onion, garlic, coriander, cumin, and caraway seeds together in an air-tight container. Pour brine over bean mixture. Cover container tightly and let sit at room temperature until liquid is beginning to bubble from the gasses, about 24 hours.
Drain brine from beans mixture, reserving the brine.
Blend bean mixture in a food processor, adding just enough brine to make acaraje mixture the consistency of thick hummus. Store blended bean mixture in an air-tight container at room temperature for 24 hours.
Preheat oven to 350 degrees F (175 degrees C). Place acaraje mixture in the bowl of a stand mixer and beat until fluffy.
Dip a tablespoon into the hot oil to assure the acaraje mixture doesn't stick to the tablespoon. Scoop acaraje with the coated tablespoon and gently drop acaraje mixture into the hot oil; repeat process until about 6 are frying at 1 time.
Cook acaraje in the hot oil, flipping occasionally for even cooking, until golden brown and crispy, about 4 minutes per batch. Transfer acaraje to a paper towel-lined plate; season with sea salt.
