Wash the cucumbers under cold water and scrub off any blossom dust. Trim a thin slice off the blossom end of each one, the end opposite the stem, since it holds an enzyme that softens pickles during a long ferment.

Weigh 1.5 L / 6 cups of non-chlorinated water into a bowl and stir in 52 g sea salt until fully dissolved. This gives a 3.5% brine, strong enough to favor lactobacillus over spoilage bacteria.

Lay 2 grape leaves and half the garlic, dill, peppercorns, mustard seeds, bay leaves, and juniper berries in the bottom of a 2-liter / 2-quart fermentation crock or wide-mouth jar.

Pack the cucumbers into the crock as tightly as you can without crushing them, standing smaller ones upright and laying larger ones on top.

Scatter the remaining garlic, dill, spices, and chili flakes over the cucumbers, then tuck the remaining grape leaves on top as a final layer.

Pour the brine over the cucumbers until fully covered, leaving about 2.5 cm / 1 inch of headspace.

Set a fermentation weight, or a small plate topped with a water-filled bag, directly on the cucumbers so every piece stays under the brine line. Any cucumber that floats above the surface will mold within a day or two.

Cover the crock loosely with a clean kitchen towel or cheesecloth secured with a rubber band. Set it on the counter out of direct sunlight, at 18 to 21 C / 65 to 70 F.

Check daily and skim off any thin white film with a spoon, that's harmless kahm yeast. Discard the batch only if you see fuzzy pink, black, or green mold.

Start tasting on day 5. The pickles are ready when the brine turns cloudy and the cucumbers taste tangy and sour, with a dull olive-green color rather than bright green, usually by day 7 to 10.

Once fermented to taste, move the crock, or transfer everything to jars, to the fridge, keeping the cucumbers fully submerged in their brine. Slice or serve whole.