How to Preserve Olives

April 28th, 2016

On the farm we use most of our olives to make extra virgin olive oil – a medium style, but complex blend of five cultivars: Frantoio, Mission, Don Carlou, Leccino and Corratina. We also preserve the whole fruits in brine or salt for the two restaurants, black calamata and green Nonchellara olives.

Olive trees are still covered with black fruits at the moment, and you too can boast with your very own preserved olives – all it takes is a bit of handiwork and patience. The process is simple and the end product well worth the wait.




To preserve its characteristic fruity and slightly bitter taste, olives can be pickled or dried. Key to the process is salt, which draws out some of the fruit’s pungent bitterness and unlocks its best flavour qualities.

Important to remember: All olive varieties start off green and turn black as they ripen. Green olives are harvested when the fruits have reached full size, but before it darkens in colour. These will have a more zesty taste whereas ripened black olives are softer on the palate with a full-bodied taste. Here’s how we preserve our olives in brine.



Preserving olives in brine


  • Place fresh black olives (harvested or bought) in a basket to prevent bruising
  • Remove any diseased or damaged fruit
  • Wash olives with clear water to remove dust and leaves

To make the brine:

  • Add 1kg salt to 10 litres of water (1:10) and mix to dissolve.
  • To test if it’s sufficiently salty, make a solution of 5%, 7% and 10% by adding 50g, 60g and 100g of salt to a litre water. Then add a raw egg and determine how much of the egg is visible above the surface of the water in each solution. Put the same egg in the olive brine to determine the salt concentration.  If it sinks, more salt should be added to the water.

To process olives:

  • To quicken fermentation, make a vertical cut in each olive with a sharp knife. Whole olives can be used, but will take longer to de-bitter and preserve
  • To prevent bruising of olives fill a bucket with a few litres of brine before adding the olives. For processing about 10-13kg of fresh olives, a 20-litre bucket will be sufficient
  • Add the rest of the olives to the bucket and cover with brine
  • Cover the bucket with a lid, but do not seal tight. This will allow fermentation gases to escape and prevent dust from gathering on the surface
  • Keep the olives in a cool room away from sunlight
  • To activate the debittering process and mix in the salt gathered at the bottom of the bucket, regularly stir the olive and brine mixture (especially in the first two weeks)
  • Continue checking and stirring the olives regularly. The salt level needs to be maintained at 10% throughout the process. If the salt level drops below 6% there is a chance of spoilage.
  • Regularly taste the olives for bitterness. The debittering process requires some patience, seeing as it can take up to six months
    *A white layer of yeast might form on top of the water. This just shows that fermentation is taking place, so nothing to be concerned about.


Babylonstoren olives

To bottle:

  • Lay the olives on a towel for a few hours to oxidate
  • Place olives in a clean bucket and soak in vinegar for 12 hours to stop the fermentation process
  • Sterilise jars or bottles prior to bottling olives. There are plenty of ways to do this – in the
    oven, microwave, dishwasher or even on the stove
  • Bottle the olives in 6% brine solution (salt water) adding 1 cup of vinegar to every 4 litres
    of brine. For extra flavour, herbs such as rosemary can be added to the brine
  • After filling the jars or bottles, top the brine with 1cm layers of good olive- or
    vegetable oil and secure with lids

Pickled olives are old favourites on tapas boards and salads, but our chefs combine it with chocolate! Try the dark chocolate terrine with olives and walnuts from the Babel cookbook.

Preserving Olives in Salt

If preserving in brine sounds like too much work, you can always preserve your olives in salt. Liesl shows you how.









  1. Cathy says:

    I have just bought fresh olives and I rinsed then in water and they are now in10 per cent salt. My olives seem to have a white dusty mould on them. How do I clean them?

    • Babylonstoren says:

      Dear Cathy, thank you so much for your question. The white layer that forms on top of the olives are normally a sign that fermentation are taking place. It is a good sign. What you can do is to take a sieve and just scoop it from the top.
      Remember to ensure that your container is always full to the top with 10% salt solution and use something to keep the olives under the water. As soon as the olives will be in contact with direct oxygen it will turn brown.
      Hope this helps. 🙂

  2. Terry says:

    How do I keep the nice green colour of green olives? My green olives have a brow/green colour by the time of botteling

    • Babylonstoren says:

      Hi Terry, the answer from our olive oil maker – It is important to measure your salt solution regularly and adjust to 10%. When ageing the olives the brine must have a 10% salt concentration.
      Also you need to keep the olives under the water all the time to prevent the olives from oxidizing and turning brown. Most reasons for the brown colour is when your green olives are in contact with air.
      Place a plastic lid on top of the olives with something heavy on top to keep the olives down.
      Hope this helps.

  3. Ruth says:

    Have followed the first steps and have the loves in the brine with oil on top.
    Now what?
    How long will it take to preserve – ie before ready to eat?
    Do I need to put fresh brine in? Or just add salt every so often?

    • Babylonstoren says:

      Hi Ruth, our olive man answers the following: Is it green or black olives? If it is a small volume like 10li bucket the easiest will be to replace the brine every 2 months. Then you know the solution will be 10%. If the volume gets bigger it is good to buy a salt refractometer. At 10% brine the olives can stay in the container (container must be full and olives submerged under water all the time) for 12 – 18 months. You can start tasting it from 6 months, but we age for 12 – 18 months in 10 % salt solution.

    • Martine says:

      Hi Ruth 🙂

      It should take 2 – 3 months before they are ready to eat from the stage you have them at now. However, I’ve left my olives for up to a year (*) before I opened them and they were DELICIOUS! If you’re doing this for the first time, I’d recommend to open a jar about one month into the bottling stage to taste – I’m not a fan of the bitterness of “youngly preserved” olives at all, but that is just personal preference – many love it. The longer you leave them, the milder they get. Hope this helps!

      *That is, if you have made use of sterilised jars and lids, filled them RIGHT up to the top, sealed them very tightly, and kept them in a cool, dark place.

  4. Hentie says:

    How do I measure my salt solution to continuously be at 10%? I have now started with a 1kg salt/ 10l water solution and placed freshly picked olives in a bucket.

    • Babylonstoren says:

      Dear Hentie, if it is a small volume like a 10 liter bucket, the easiest will be to replace the brine every 2 months. Then you know the solution will be 10%. If the volume gets bigger it is good to buy a salt refractometer.

  5. Nolene says:

    Hi I have brined my olives until the bitterness has gone. What now? Can I bottle them in olive oil with flavourents? How long will they last in olive oil or is it better to store them in vinegar with spices?
    Cheers Nolene

    • Babylonstoren says:

      Hi Nolene, thank you so much for your question. I asked out olive man to get in touch with you so please keep a look out for his email in your inbox, he will best answer your question. Greetings, Jessica

  6. Susara says:

    My olivea are in salt solution for 4 days Most of bitterness are gone What now ? Please help

    • Elsa says:

      Dear Suzie – we normally keep our olives in the 10% brine for 1 year.

      4 days are too short. You can taste them after 6 months and then decide if it is good enough. Remember to keep the olives submerged in the brine and the containers must be filled to the top. Hope this helps!

  7. Alison Murphy says:

    I have bribed my olives in a lemon, garlic, salt and spice mix. They have a great taste…my question is what do I do with them now so they are preserved?

  8. Peta Basson says:

    Hi please can you help me?
    I have now taken my olives out of the brine solution after 8 months and am ready to bottle them. How do I make up a 6% solution of brine (ratio of salt to water please)?
    Kind regards
    Peta Basson

  9. Annette says:

    Good day,
    Can I use your olive oil for high heat cooking?

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