Preparing the Tomatoes

1. Cut the tomatoes into [q:1/4]-inch rounds, cutting out the tough core in the top slices.
2. In a large bowl, combine 3 quarts cold water with the pickling lime and add the tomatoes. Cover the bowl and set aside at room temperature for 8 hours or overnight.
3. Drain in a colander, rinse well, and cover with cold water. Let soak for 1 hour, then drain. Repeat the soaking and draining two more times to remove all of the lime; do not skip this step, as it’s necessary to remove all of the lime so that the pickles will be acidic enough for preservation.

Canning Process

1. Prepare for water-bath canning: Wash the jars and keep them hot in the canning pot, and put the flat lids in a heatproof bowl.
2. In a wide, 6- to 8-quart preserving pan, combine the vinegar, sugar, salt, celery seeds, celery, and ginger. Bring to a boil, then add the drained tomatoes. Return to a boil and cook, gently pressing down on the tomatoes to keep them mostly submerged, for 15 minutes. The tomatoes will become somewhat translucent.
3. Ladle boiling water from the canning pot into the bowl with the lids. Using a jar lifter, remove the hot jars from the canning pot, carefully pouring the water from each one back into the pot, and place them upright on a folded towel.
4. Drain the water off the jar lids.
5. Use a slotted spoon to transfer the hot tomatoes to the jars. (If you’d like, insert a round of onion or two between some of the tomato slices.) Ladle in the hot syrup, leaving [q:1/2] inch headspace at the top. Use a chopstick to remove air bubbles around the inside of each jar.
6. Use a damp paper towel to wipe the rims of the jars, then put a flat lid and ring on each jar, adjusting the ring so that it’s just fingertight.
7. Return the jars to the water in the canning pot, making sure the water covers the jars by at least 1 inch. Bring to a boil, and boil for 10 minutes to process.
8. Remove the jars to a folded towel and do not disturb for 12 hours. After 1 hour, check that the lids have sealed by pressing down on the center of each; if it can be pushed down, it hasn’t sealed, and the jar should be refrigerated immediately. Label the sealed jars and store.