Wash each cucumber under cool running water and scrub gently with a soft brush to remove any dirt or residue. Trim about one-quarter inch off both the blossom and stem ends to prevent softening during fermentation.

Wash glass jars and lids thoroughly with hot soapy water, rinse well, and optionally run through a hot dishwasher cycle to sterilize and warm them.

In a small bowl, combine black peppercorns, mustard seeds, coriander seeds, and red pepper flakes. Divide the spice mix evenly among the jars, placing about one-half to three-quarters teaspoon at the bottom of each jar.

Layer fresh dill sprigs on top of the spices in each jar, then add half of the garlic cloves.

Pack cucumbers vertically into each jar, fitting them snugly but leaving space for brine to flow. Add remaining garlic cloves and bay leaves on the top.

In a large stainless steel stockpot, combine 3 cups water, 3 cups apple cider vinegar, and 3 tablespoons pickling salt. Stir over medium-high heat until the salt dissolves completely, about 3 to 5 minutes. Remove from heat and let the brine cool for 10 minutes.

Carefully pour the warm brine over cucumbers in each jar, leaving about one-half inch headspace. Use a funnel to avoid spills and ensure all cucumbers are submerged.

Wipe rims of jars clean with a damp cloth, then screw on lids securely but not too tight to allow gases to escape during fermentation. Label jars with the date.

Place jars on a clean countertop away from direct sunlight and ferment at room temperature (65–75°F) for 3 to 7 days based on preferred flavor. Taste starting at day three and continue until desired tanginess is achieved.

Once fermentation reaches your preferred flavor, screw lids on tightly and transfer jars to refrigerator. Pickles will keep up to three months refrigerated.