Day 1: Scrub cucumbers gently under running water. Trim off 1⁄8 inch (3 mm) from each end and prick all over with a fork.
In a large bowl, layer cucumbers and salt, using about one-quarter of each per layer. Add cold water to cover by about 1 inch (2.5 cm). Place a plate on top to weigh down cucumbers. Cover and let stand at a cool room temperature for at least 12 hours or for up to 24 hours.
Day 2: Prepare canner, and sterilize jars and lids.
In a colander, working in batches, drain cucumbers and rinse well. Drain again and set aside.
In a pot, combine pickling spice, water and vinegar. Bring to a boil over medium-high heat. Boil for 1 minute. Reduce heat to low, cover and simmer for 5 minutes or until liquid is flavorful. Discard spice bag and keep liquid hot.
Working with one jar at a time, place 1 bay leaf, 1 piece of garlic and 1 dill head in hot jar. Pack cucumbers into jar, leaving 1 inch (2.5 cm) headspace, and top with 1 piece of garlic and 1 dill sprig. Pour in hot pickling liquid, leaving 1⁄2 inch (1 cm) headspace. Remove air bubbles and adjust headspace as necessary by adding hot pickling liquid. Wipe rim and place hot lid disc on jar. Screw band down until fingertip-tight.
Place jars in canner and return to a boil. Process for 15 minutes. Turn off heat, remove canner lid and let jars stand in water for 5 minutes. Transfer jars to a towel-lined surface and let stand for 24 hours. Check lids and refrigerate any jars that are not sealed.
Tips: -To ensure crunchy pickles, use the freshest, crispest cucumbers for this recipe. This size of cucumber is easy to pack into jars and tends to have the best texture. If you have larger cucumbers, cut them into halves or quarters. They may have a softer texture once pickled. -To make a spice bag, cut a 4-inch (10 cm) square piece of triple-layered cheesecloth. Place the pickling spice in the center of the square and bring the edges together into a bundle. Tie tightly with kitchen string. Alternatively, use a large mesh tea ball.