How To Cure Olives
Now that you have started growing your very own olive tree, and know how to identify a good quality table olive, you could also look at starting your very own home ‘curing process.’ Olives must be cured before they can be eaten, due to the bitterness of oleuropein, (a polyphenol) which makes the raw olive fruit totally unpalatable. If you have accidentally bitten into a raw olive, you will be familiar with the bitterness that follows.
Cured olives should have an attractive appearance, a pleasant taste, a firm but not hard texture and an adequate shelf life. Starting the process with a high quality, fresh olive fruit is essential; successful curing further depends on the curing technique, care applied and hygiene of the process.
There are a few common ways to cure your olives – including dry curing with salt, water curing and brining – and each produces a distinct flavour and texture profile, while being suited for different types of olives.
Best suited for black olives (as they are normally mild and lack large a quantity of bitter oleuropein). This method uses a lot of water as you will need to soak, rinse and repeat for about 20 days. The process washes out the fermentable sugars together with the bitterness; thereafter the fermentation rarely can take place. Without undergoing the fermentation process, the olives will not be microbiologically stable, and should be consumed in a short space of time.
Brine curing involves soaking olives in salt water for three to six months. Under the brine, olives ferment, breaking down the bitter oleuropein and converting some of the sugar in the olives into lactic acid, which preserves and flavours the olives. Although brine-curing takes longer than water curing (which can take up to a year), this method leaves the olives sweet and full of depth. This is the method used to make Greek-style black olives and Sicilian-style green olives. A step-by-step process for unfermented home brine-curing has been added below.
Dry-curing with salt:
Fully ripe or even overripe olives are packed in salt for a month or longer. The salt pulls the moisture and bitterness from the olives. The salt is then removed, and sometimes the olives are bathed in olive oil to keep them juicy and plump. Dry-cured olives have a deeply concentrated flavour, and a wrinkly, prune-like appearance.
In some rare cases, very ripe olives can be ‘de-bittered’ either on the branch or, once picked, by basking in the sunshine.
Quick Method for Brine-Curing Black Olives (unfermented) at home.
- For best results use completely black olives.
- Rinse the black olives well and leave in clean water for 24 hours.
- Place in a 4% salt (40g/L) solution for 2 weeks.
- Keep the olives submerged and cover.
- Replace with a 6% salt (60g/L) solution for 2 weeks.
- Keep the olives submerged.
- Make up fresh 6% salt solution and flavour to taste with vinegar, herbs, spices, etc.
- Place the olives in jars.
- Bring the flavoured brine to the boil and add hot to the olives in the jars.
- Fill the jars completely and close tightly.
- Let stand for a week or two.
- Serve splashed with EVOO.
Bonus: SA Olive former Chairperson and Olives-In-Fact founder, Linda Costa has written a comprehensive step-by-step guide on everything you need to know about fermenting table olives – Table Olive Processing Made Easy.
“The aim in processing table olives, whether it be in a factory or in the home, is to produce an edible product from a fruit which, in its raw and untreated state, is completely unpalatable.” – Olive Production in South Africa by Carlo Costa.
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