Fill a 2-gallon stockpot half-full with water. Place 8 (1-quart) jars and their lids in the water bath. Bring to a boil and boil 5 minutes to sterilize the jars and lids. Remove the jars and lids using tongs or a jar lifter. Reduce heat to low and maintain a simmer.

Fill a sink with cold water. Place a cutting board near the sink. Cut the collard green stems into 2-inch pieces and rinse in cold water. Drain.

Bring the 8 cups water to a boil in a separate stockpot over medium-high. Blanch the stems, 2 cups at a time, in the boiling water, 2 to 3 minutes. Meanwhile, fill a medium bowl with ice and water. Transfer the blanched stems to the ice bath.

Bring the distilled water to a boil in a 2-gallon stockpot over medium. Add the pickling salt, vinegars, peppercorns, and bay leaves, and cook until the salt is dissolved.

Transfer the collard green stems to the hot sterilized jars; top evenly with the chiles, pink peppercorns, and crushed garlic.

Pour the pickling salt mixture through a fine wire-mesh strainer into a liquid measuring cup, reserving the peppercorns. Discard the remaining solids. Divide the black peppercorns evenly among the jars. Pour enough of the pickling liquid evenly into the jars to cover the collard green stems, filling to 1⁄2 inch from the top of each jar.

Wipe jar rims; cover at once with metal lids, and screw on bands (snug but not too tight). Place jars in simmering water in the stockpot. Add additional boiling water as needed to cover by 1 to 2 inches. Simmer about 20 minutes or until jar lids are set. (Follow the jar manufacturer’s instructions for a good seal.)

Remove from heat. Cool jars in the water bath for 15 minutes. Transfer the jars to a cutting board; let stand at least 3 days before using. Store in a cool, dry place at room temperature. Refrigerate after opening.