Have you ever wondered why some olives are green and others black?
If the natural answer lies in the different stages of ripeness, that is not the case for 'Ripe Black Olives' in a can... as they are in fact green.
Left to their own devices olives ripen to a reddish, then purplish and then finally a black colour.
But many olive producers use a short cut...
Abracadabra! Chemical magic
According to Olive Oil Source , the fruits (yes fruits, not vegetables) found in the classic supermarket cans are actually plucked at a very young light green stage.
They are then blackened artificially with a bit of chemical help.
More artificial molecules than in a science lab
The very young olives are given a plastic surgery treatment when plunged into curing vats.
Their bath first begins with dilute brine, a chemical component used to dehydrate the fruit.
Different water solubles (lye solutions) are added afterwards which cause natural phenolic compounds in the olives to oxidize to a black color.
Calcium chloride salts, iron salts (ferrous gluconate) and compressed are then air bubbled through the curing vats help develop the black color.
So there is no black dye used but the olives are treated to make them a uniform dark black.
