1½ lb. small carrots, peeled
Zest of 2 limes, removed in 1” strips with a vegetable peeler
4 bay leaves
1.2 oz. kosher salt
Two 32-oz. canning jars with canning jar bands and lids; cheesecloth
Combine salt and 6 cups warm water in a large bowl, whisking to dissolve salt. Divide carrots, lime zest, and bay leaves between canning jars. Add brine to cover carrots. Cover with cheesecloth and secure with canning jar bands (without lids). Let sit out of direct sunlight in a room-temperature spot, skimming off any white mold that forms on surface of brine, 5 days.
After 5 days, taste carrots every day; once they are tangy and flavorful (this should take about 1 week in most cases), cover jars with lids and chill.
DO AHEAD: Pickles can be made 1 month ahead. Keep chilled.