In a medium saucepan, combine 1 liter water and 80 g kosher salt. Heat gently, stirring, until the salt dissolves. Remove from heat and stir in 60 ml white wine vinegar and allow the brine to cool completely to room temperature (about 30–45 minutes).

Prepare the olives

If olives are very salty or packed in brine, drain and rinse under cold water. If you prefer quicker flavor penetration, use a paring knife to make a shallow slit in each olive or lightly crush a few with the flat of a knife. Place the olives in a clean 1-liter jar or airtight container.

Flavor the olives

Add 3 smashed garlic cloves, lemon zest strips from 1 lemon and 2 tablespoons lemon juice, 1 sprig fresh rosemary, 0.5 tsp crushed red pepper flakes, 0.5 tsp whole black peppercorns, and 1 bay leaf to the jar with the olives.

Add brine and oil

Pour the cooled brine over the olives, leaving about 1 cm headspace. Add 60 ml extra-virgin olive oil on top (this creates a flavor layer and helps seal). Ensure olives are submerged; weigh them down with a small clean saucer or a fermentation weight if needed.

Marinate

Seal the jar and refrigerate for at least 48 hours before serving, preferably 4–7 days for best flavor. Shake the jar gently once a day to distribute flavors. Taste after 48 hours and adjust — add more lemon juice or a pinch of salt if needed.

Serve

When ready to serve, bring olives to room temperature (20–30 minutes). Transfer to a serving bowl, drizzle with a little of the infused olive oil from the jar, and sprinkle with 1 tbsp chopped fresh parsley if using. Discard the bay leaf and rosemary stems before serving.

Storage

Keep olives refrigerated in their brine and olive oil for up to 3 weeks. Always use a clean utensil to remove olives to prevent contamination.