Combine flour and beer; cover and set aside for 1 1/2 hours.
Place sweetbreads in a medium mixing bowl; cover with cold water. Set aside to soak for 1 hour. Drain well; remove and discard white membrane.
Place sweetbreads and water to cover in a small Dutch oven. Bring to a boil. Reduce heat, and simmer 20 minutes. Drain well, and rinse with cold water. Cool sweetbreads completely.
Slice sweetbreads in half lengthwise. Dip in beer batter; roll in cracker crumbs. Deep-fry in hot oil (375°) until golden brown. Drain on paper towels, and sprinkle with salt. Serve immediately.