To obtain delicious olives in oil, the first step is to put them under salt. Start by choosing the best black olives: avoid those with insect holes or other damages, until you reach 2.2 lbs.
Take a bowl and alternate a layer of olives and a layer of salt, continuing until both ingredients are used. The last layer should be of salt. Let them rest for 5 days.
During this period, the olives will start releasing water. After 5 days, transfer them to a colander, mix them by hand, and let them rest for 15 days, stirring occasionally. It’s advisable to place a bowl or plate under the colander so the liquid falls into it without dirtying the surface below.
After 15 days, taste an olive. If it still tastes bitter, add a couple of pinches of fine salt and let it rest for another 5 days. If they are ready, you can proceed with the preservation.
Rinse the olives with cold water and let them drain for a couple of hours. Gently pat them dry with kitchen paper to ensure they are dry. Transfer them to jars, adding oregano and garlic (in pieces or whole cloves, peeled). If you like, you can add a few sprigs of wild fennel and some chili pepper.
Cover the olives with olive oil, leaving about an inch of space between the oil and the lid. Close the jars and store them in the pantry: if well covered with oil, the olives will keep for about two months.