Layer the pickles, add the cucumbers, dill, garlic and bay leaf to a large (about 1 quart or 1 liter) jar, layering the dill and garlic between the cucumbers if possible
Mix the brine. In a measuring jar, briefly whisk together the water vinegar, salt, peppercorns and crushed red pepper flakes until combined.
Combine. Pour the brine over the cucumber mixture. Then cover the jar securely with a lid and give it a good shake to combine. If needed, press the cucumbers down so that they are more or less fully submerged.
Refrigerate for ideally at least 1 day before eating, although the pickles will be lightly brined and ready to enjoy after just a few hours if you would like. Pickles can be stored in a sealed jar in the fridge for 1 week!