If, like me, you’ve ever been tempted to nab an olive from a tree and popped it straight in your mouth, expecting table olive type flavour, you’ll know just how mistaken that is. Eek!
No matter how long that olive stays on the tree, it’s not going to sweeten!
So if you’re growing olives on a tree in England and thinking it’s about the climate, think again.
That little green fruit is full of oleuropein, a substance that makes it super-bitter.
For an olive to be edible, it has to be treated.
Pickle your own
One of the most satisfying things ever has to be hand-picking your own olives, ideally under a baking sun, rinsing them in water (ideally from a fresh spring) and soaking them, full of hope that you’ll have lovely table olives within a few weeks.
Preparing your Olives
To prepare, take off the stems and leaves (and discard). Check for any deformed, very hard olives with miscoloured spots. They’ve usually been ‘got’ by flies. (Discard!)
Give them a good rinse and you’re ready to start.
The process - soaking method
Olives can be debittered by pricking the skins (or hammering them, but that seems a bit brual and leaves the olives ‘mashed’) and soaking them in water, changing the water regularly. This method, using water alone,can take months and the water MUST be regularly changed.
Fermenting them in salt water, brine, is quicker, and usually takes just two weeks. Again, the water MUST be regularly changed.
You just keep changing the water every day or two until you have the softness of flesh you want. (Many Spanish people in rural areas enjoy them still quite hard.)
Once you have the texture you want, you can put them in a clean, sealed container in brine or oil. Personally I like olive oil, but that can be expensive when you’re still experimenting.
It’s popular to add other flavourings at this stage: strong herbs like fennel (hinojo) or basil (albahaca) which hold their own well, spices, lemon, or garlic are among the favourites.
Note: you will get scum during the process - this is not mould and can be washed away with the water change.
Adding lemon or vinegar can actual help to make them LESS bitter - the acid apparently helps break down that oleuropein. (Am I feeling grand for using the term?! I’ll be honest, I have to look it up to remind myself!)
Black olives
If you’ve left your olives to get really ripe and turn black, you might want to pickle them in red wine vinegar. Once you’re ‘debittered’ the olives, tip off all of the brine (drain well) and leave the olives to stand in a bowl, and with medium/coarse salt – around 100 g for each kilo of olives. Cover with a clean cloth and leave for around 10 hours. Then rinse off the salt and once fully drained transfer the olives to a jar or bowl. Cover with red wine vinegar, seal the lid, and leave for two days. The olives will become sweeter and softer - drain off the vinegar and then fill the jar with olive oil, covering the olives and sealing.
Commercial and Some Domestic Production Using Lye
Many people now use lye (sodium hydroxide) to help speed the process. I personally went to find it and thought I was was being sold caustic soda, which I couldn’t bring myself to use on food - but indeed it is, in Spanish, sosa caustica.
Don’t let my over-sensitivity to lye/chemicals stop you trying it: almost every olive on a supermarket shelf will have been cured using a lye.
And I found this lovely video explaining how you do it properly!
