How Black Olives are Produced

Black olives

Did you know that our black olives are not black when they’re picked from the tree? Yes, that’s right! Contrary to popular belief, the best time to harvest black olives is when they’re perfectly ripe but still green, normally between September and October in the northern hemisphere.

Green table olives are treated with lye to make them ready to eat, whereas black olives are treated by oxidation, which makes them go black. Both these processes respect the olive’s nutritional properties, although these vary between green olives and black olives.

The main difference between the properties of green and black olives is the salt and iron content, which changes after the oxidation process. Black olives contain less salt and more iron than green olives, which makes them healthier and great food for helping to prevent and treat anemia.

How Black Olives are Produced - Aceitunas Torrent
Aceitunas Torrent’s Black Olives

Aceitunas Torrent are specialists in producing and marketing black olives in all their different forms: whole, pitted and sliced.

How are black olives produced using oxidation?

To produce top quality black olives, the same procedures mentioned above for green olives have to be followed, with the addition of the oxidation process.

Once the olives are harvested green, they are cleaned and any remaining leaves are removed. We then classify them by size and conserve them in brine.

To pack them for sale, we select the olives of the right size for each brand and treat them with caustic soda, which makes them go black. At this stage of the process, they are exposed to air and the oxygen changes their colour, makes them sweeter and softens the olive pulp.

To make the black colour permanent, the olives are treated for a second time with water, air and ferrous salts, giving them that glossy black hue so characteristic of our olives.

Our black olives are now ready for packaging! Unlike green olives, which are pasteurized and packed, black olives are sterilized to prevent bacteria from growing.

Just like the processes involved in green olives, producing black olives requires a great deal of skill and expertise, which we have acquired here at Aceitunas Torrent throughout our 120-year history.