Prepare the Cucumbers: Wash and scrub the cucumbers thoroughly and cut them into quarters lengthwise.
Sterilize the Jars: Wash and sterilize your glass jars (4 8-ounce OR 2 16-ounce) lids and bands. You can do this by running them through a dishwasher cycle or boiling them in a large pot of water for about 10 minutes. Keep the jars hot until you're ready to fill them.
Prepare the Brine: In a saucepan, combine the water, vinegar, and pickling salt. Heat the mixture over medium heat until it comes to a simmer. Stir until the salt is fully dissolved. Remove the brine from heat.
Pack the Jars: In each sterilized jar, divide the garlic, fresh dill, mustard seeds, coriander seeds, black peppercorns and chilli flakes (if using). Pack the cucumbers into the jars tightly, leaving about 1/2 inch of headspace at the top.
Pour in the Brine: Carefully pour the hot brine over the cucumbers in each jar, ensuring they are fully submerged. Leave about 1/2 inch of headspace.
Remove Air Bubbles: Gently tap the jars on a countertop to release any trapped air bubbles. Enjoy!