Place the Kalamata olives in a colander and rinse under cold running water. Discard any stems, shriveled or damaged olives. If olives are particularly salty (if coming from a jar), soak them in fresh water for 30 minutes and drain once to reduce surface brine.

Prepare brine

In a medium saucepan combine 4 cups filtered water and 1 cup kosher salt. Warm gently, stirring, until the salt dissolves completely. Remove from heat and let the brine cool to room temperature. Once cool, stir in 1/2 cup white wine vinegar.

Flavor the brine

In a clean 1-liter (or larger) glass jar or nonreactive container, add 1 tablespoon crushed red pepper flakes, 2 teaspoons dried oregano, 2 bay leaves, 1 tablespoon black peppercorns and 4 smashed garlic cloves. Pack the rinsed olives into the jar, leaving about 1 inch headspace.

Cover with brine

Pour the cooled salt-and-vinegar brine over the olives, ensuring they are fully submerged. Use a small nonreactive weight (a clean jar lid or a small zip-top bag filled with water) to keep olives under the brine to prevent mold.

Cure time

Seal the jar loosely (to allow any gases to escape) and store in a cool, dark place or refrigerator. Let olives cure for at least 7 days for light flavor absorption; for deeper flavor and mellower bitterness, cure 2–4 weeks. Check every few days to skim any surface foam and to ensure olives remain submerged. Taste after 1 week and then weekly until desired flavor.

Finishing & Serving

Drain and rinse (optional)

When olives have reached the desired flavor, drain off the brine and give them a quick rinse if you prefer a less salty surface. Pat dry gently with paper towels or a clean kitchen cloth.

Marinate and finish

Transfer the olives to a serving bowl. Drizzle with 2 tablespoons extra-virgin olive oil, add 1 teaspoon fresh lemon zest, and sprinkle 1 tablespoon chopped fresh thyme or oregano and 1 tablespoon chopped parsley if using. Toss gently to coat and allow to rest for 30 minutes so flavors meld.

Serve

Serve at room temperature as an appetizer, part of a mezze platter, or as a garnish for salads and cooked dishes. Leftover olives keep refrigerated in fresh brine or lightly oiled in a sealed container for up to 1 month; check for off smells or mold before use.