🫒 Greek-style black olives

Greek-style black olives are natural black olives that lose their bitterness without lye, by fermenting for months in strong brine. Under the International Olive Council standard they are “natural black olives” — ripe or nearly ripe fruit placed directly in brine. This is how the Greek cultivars Konservolia and Kalamon and the Turkish Gemlik are prepared.

Black table olives are picked in late autumn. The fruit is washed, sorted and put into closed containers with a solution of 8–10% salt. Bitter oleuropein slowly passes into the brine and breaks down; fermentation is carried out by yeasts together with lactic acid bacteria, and it is the yeasts that give the olives their characteristic taste. The process takes about 6–9 months, and the salt, which gradually drops, is brought back to its initial level.

If the skin fades, the olives are aired for a few days, as they darken in the air. They are packed in fresh brine, sometimes with vinegar, and the elongated Kalamon is often slit so that it absorbs the marinade better. Under the standard, the finished product has at least 6% salt, a pH no higher than 4.3 and an acidity of no less than 0.3%.

These olives taste tangy and salty, with a slight bitterness. Research reviews note that phenolic compounds are best preserved in natural olives, whereas lye reduces them.

Why it matters to you. Not all black olives are alike. On the label, look for the word “natural” or the cultivar name. If the ingredients list ferrous gluconate or ferrous lactate (E579, E585), these are olives darkened by oxidation — so-called Californian olives: the standard permits these colour stabilisers only for them. A uniform jet-black colour is another sign, whereas natural olives range from reddish black to violet and chestnut.