Californian Black Olives© Denzil Green
California Black Olives, owing to the way they are processed, tend to taste quite bland compared to European ones. More than 90% of olives in California are made into Black Olives.
These are the Black Olives that have given all the other Black Olives a “black” reputation in North American.
They are not actually Black Olives at all. They are olives that are picked green so that they can be mechanically pitted and processed.
The green olives are cured in a solution of lye for about a week, during which time the solution is changed a few times and aerated with blasts of air. The reaction in the solution causes the olives to oxidise, turning them black. The olives are then washed in water to wash the lye away, then bathed in an iron salt (ferrous gluconate) solution, which stabilizes the black colour, so that the colour will stay and not fade out. They end up a jet-black colour.
They are usually canned, packed in brine. Because they are canned in a very low-salt brine, the cans need to be heat-sterilized so that they won’t go bad. That’s why tins are used, because they stand up better to the heat than glass. The olives actually get cooked a bit in the tin, changes the taste and texture a bit further.