Olives should be picked when dark and ripe, but not over-ripe, as they bruise easily. Wash and slash each olive deeply on each side with a knife and place in large, non-metal containers. Pour a solution of salty water (4 tablespoons of pickling salt to 1 quart of water) over olives. Leave the olives uncovered and in a cool place.
Stir a little each day. Change the brine each week. Sample after the third week, and continue the process if olives are still bitter.
When they are no longer bitter, rinse the olives well. Fill screw-top quart jars 2/3 full of olives. Prepare a mixture of vinegar and spices: 1 pint water, 1 pint vinegar, 1 tablespoon of salt, 1/2 teaspoon oregano, 2 small lemon wedges, and 1 clove of garlic, and pour over olives.
Top with a 1/2 inch layer of olive oil and screw lid tightly. Invert the jar for a week. Store right-side up in a cool place. Olives will keep for several years.