In part 2 of this series I’m dealing with brine cured olives. 

If you want to read about water-curing olives, then go my previous post here.

This takes the longest of all the methods, but is also the easiest. The lack of contact time is a huge bonus for me, and although the months, and months, and months of waiting seem impossible at the start, if you hide them in the back of the pantry you’ll forget they’re there! Until, one day, you remember, and it feels as if someone’s given you a super special yummy gift! And if you do this every year, you’ll always have a supply of these little treats to hand anyway, so it won’t matter that the new batch can’t be touched!

Brine curing relies on a natural fermentation process. Basically, you put the freshly picked olives in an acidified brine solution which creates a selective environment that favours the lactic acid bacteria who will be doing all the work. These bacteria would make the brine acidic anyway, once they got going and releasing lactic acid, but this gives them an ideal home to start in, and deters other less desirable organisms in the meantime.

The olives (and you) don’t need to go through the whole tedious changing the water every day for a month process, you just put them straight in the brine, and hide them somewhere cool and dark. And you don’t have to crack or slit the fruit either. Easy peasy! Most people recommend NOT washing the fruit, as the organisms you want to encourage are naturally present in the bloom on the surface.

I was a bit apprehensive about fermentation in general but I’ve been reading more about it over the past couple of years, initiated by sourdough. I think we’re so conditioned to buy packaged food that has either been sterilised or pasteurised, and it has to be kept in the fridge, and it has to be eaten by the best before date…., that we’re forgetting all the techniques that our predecessors used to preserve food. So honestly, the thought of putting fresh fruit in salt water and vinegar, leaving it for 6-9 months, and then eating it seems pretty weird. But I like weird, and science, and food, so obviously I gave it a go. And having eaten the final product I can report that I am alive and well!

Drained olives after several months of fermentation.

This batch of olives came from a neighbor who has a GINORMOUS olive tree, which we reckon is probably about 100 years old. It’s bigger than the one in the Royal Tasmanian Botanical Gardens which is around that age. We don’t know what variety it is, but the olives are BIG! Perfect for table olives! I didn’t know if this batch would work because when I picked them it was pretty late in the season, and the fruit was ripe, becoming a bit soft. The final texture of the cured olives is surprisingly firm though. In my opinion, they’re perfectly salty too! Some people find the 10% brine leaves the fruit too salty for them, in which case they can be transferred to a 5% solution for a few days before eating, just to lower the salt concentration.

Big old olive tree at the Royal Tasmanian Botanical Gardens

Some authors recommend changing the brine at two to three months, and I meant to do this, but I forgot! And at the end of eight months the brine still looked fine. If you do want to change it, DO NOT wash the olives, they will be covered with the good, hard working bacteria you want, and once they’re installed in their new briney home they’ll get back to their job! The olives can be stored in the brine in a cool dark place for at least a year. The longer the fermentation goes on for, the softer the olives will become, so if you want to delay this, I’d recommend putting them in the fridge after their final bottling as this slows the process down.

Herbs, spices, and other flavours can be added to the brine, but only do this after the olives have been curing for at least two months. If the flavourings are present in the brine for a long time it can become overpowering. If this happens, you can put them back in a plain brine solution to try and reduce it. (But I wrecked one batch using lemon slices for too long.)

One perfect olive!

Brine-cure Olive Recipe

Time = several months

Difficulty = very easy

Description = Make your own naturally fermented green or black olives

Recipe Ingredients
– Green or black olives.
– 10% Brine and red wine vinegar solution (100g salt and 1L of water, heat and stir until dissolved. Cool and add 150ml of red wine vinegar. Adjust volumes as needed.)
– Extra virgin olive oil
– Herbs and spices as desired

Recipe directions
1. Place the olives in a large jar.
2. Cover with the brine solution so all the olives are submerged – THIS IS VERY IMPORTANT!
3. Put something on top to weight them down, like a small jar filled with water, which fits inside the neck of the large jar.
4. Cover lightly with something – I used cling film secured with a rubber band which would let out any gas that accumulated in the earlier part of the fermentation.
5. Place the jar of olives and brine in a cool dark place, on a plate in case of leakage!
6. Forget about them for at least three months!
7. Taste the olives and decide whether to leave them to continue their fermentation, or put them into smaller jars, either with new brine, or the original brine filtered.
8. Add flavourings to the brine if desired.
9. To serve, drain and dress with extra virgin olive oil and perhaps some lemon juice and fresh herbs.

The next post in the series will be in about another week. In the meantime, I’d love to know if you’ve tried curing your own olives, and what methods work for you. Do let me know in the comments!

And finally, if you’d like to know when we’ve set our “Pick your own olives” dates, so you can try this at home, then sign up to my mailing list. Click here to go to the form, and I’ll make sure you don’t miss out!

The Art of Fermentation by Sandor Katz