How to Cure Olives
By Ann M. Evans
I’ve cured olives with dry salt, water, brine, and lye. The latter is easier, and that is what I’ve settled upon. Once you get over the scary skull and crossbones on the lye container, it’s ok, and the water can be discarded down a laundry room sink. I do not pressure can olives, for that you can consult your state’s cooperative extension service for a recipe.
For this recipe, harvest your olives when they are still green, but have some purple and black. In my case in Davis, California, that would be mid to late November, or early December. Right now I have an Italian Frantoia varietal olive tree, so that’s what I’m harvesting and curing.
Once you’ve harvested, you have to soak the olives in the lye to soften them, rinse them over a few days in water to remove the lye, and then brine them over a few days to provide flavor. Think of it as three separate processes. Curing olives with lye is time intensive, it takes about 2 weeks total from picking the olives to eating them, but not nearly as long as the salting or brining method.
I took much of this information from a variety of sources, including an Agriculture and Natural Resources (UC) publication 8267, which I recommend you consult. I do not go into all the food safety and handling of lye information here.
Note: The first process, soaking in lye-water solution, takes 10-12 hours, so plan your start time accordingly.
2 pounds of olives (or any poundage, just cover with water and add lye appropriately)
3 tablespoons granular/crystal lye (100 percent pure, available in most hardware stores, note that it will have a poison sign on it)
Pickling salt and herbs, citrus, spices for flavoring the olives. See 8.
Lye-resistant container to hold curing olives
1-gallon container for mixing brine
Glass jars to hold olives in the brine
Wooden, plastic or stainless steel spoon to stir the olives in lye
Cloth to cover the olives in the lye solution
A plate or weight to hold the olives down in the lye solution
The Softening in Lye Solution Stage
1. Pick olives when green, slightly purple. (November/December in Northern California). It’s best to have roughly the same ripeness and size in your olives.
2. Fill a food grade plastic container with one-gallon cold water and add the lye. Do not add the water to the lye; add the lye to the cold water. Note: I use tight fitting rubber gloves, like for dish washing. I wear my glasses so nothing can get into my eyes. Lemon juice or vinegar will neutralize lye burns, should some get on your skin.
3. Cover olives with a cloth (I use an old dish cloth) and weight down the cloth with a plate so that the olives are submerged.
4. Every two hours, stir the water/olive mixture. Check it for lye penetration. To test, remove a few olives using a plastic, wooden or stainless steel spoon (I use a slotted stainless steel spoon with a very long handle.) Rinse the olives. Cut them with a knife through to the pit and remove a wedge so you can see the flesh, which will be yellow colored where the lye has penetrated, and white where it has not. It should be yellow to the pit. When done, the olive will be easy to cut. This may take 10-12 hours.
5. When lye solution has penetrated, drain the olives and rinse them twice, then cover with cold water. Note: Drain the lye solution ONLY as recommended on the container. (I use a laundry sink.)
The Rinse/Wash/Lye Removal Stage
6. For the next several days, drain and rinse the olives twice a day. After 2-3 days, begin to taste the olives until you no longer taste lye (soapy taste.) It should taste sweet and fatty, with no bitterness, and according to some sources, little like a tiny avocado. This may take 7-8 days. The water color will go from an olive green to clear.
The Brine Stage
7. For short-term storage in the refrigerator, which is all that I do, prepare a light brine of 6 level tablespoons of pickling salt per gallon of water. For 2 pounds of olives, this will be one gallon. Cover the olives with brine and let stand for 2 days.
Note: If the brine turns pink, you haven’t removed all the lye, and you need to rinse your olives again as in 6. After 2 days of brining they are ready for use.
8. Flavoring the olives. I put my olives into clean quart size canning jars with lids, add the brine, and then some herbs and spices. This is up to you. I add things that are handy in my garden or in my pantry from my garden like several cloves of garlic, a bay leaf, and some sliced lemon or orange peel. You can also add coriander seed, black pepper corns, cumin seed, dried chiles, fennel seed, or leafy herbs such as oregano or thyme.
9. They should keep in the refrigerator up to a year. Be sure to label with the year and the olive varietal.