Our tree only seems to produce olives every second year, which is not unusual. So we make the most of this years 3.3kg (7.3 lbs) harvest. The olives picked vary in colour from green to mottled green and purple through to deep luscious blue-black. The flesh is a little tender, showing that it is just the right time to preserve. The olives should not be left on the tree too long as they may become overripe, which is not ideal for preserving.
The recipe for preserving is really simple (see link here to my previous post). It is important to separate the olives into a least two groups as the lighter coloured green or mostly green will need more time for soaking – up to 5 days, the darker fruit needs only 2-3 days. To get an idea if they are ready to go the brining stage, taste a bit from the raw olive. If it seems really bitter, then change the water and soak for another day or so.
The brine solution is made up of about 6 tablespoons (about 6 heaped UK & US tablespoon measures) of fine sea salt to 1 litre of water (about 2 pints). Use the “egg test” to see if the brine is sufficiently strong. To do this float a raw egg in the brine. The egg should be raised out of the liquid showing a circle about 3cm in diameter (about 1 inch).
Put the drained olives in large jars, add also some dried herbs if you like, such as bay leaves. Add brine mixture to cover olives. Then top the mixture with a grape leaf (previously blanched or already preserved) and top with a bit more brine to cover this also. The olive leaf ensures that the olives are submerged in the liquid while they are curing.
Cover the jar with a tight fitting lid and place in a dark cupboard for a number of weeks, probably at least 8 weeks. Taste them and if they seem to be ready, top the jar with a layer of olive oil. They can successfully be kept in a dark, dry place for months. To serve, remove the olives you need from the jar (seal jar and replace back to storage), rinse the olives briefly and then dress with olive oil, vinegar and herbs (if liked) and store in the fridge.