Brine Cured Olives
Olives can be cured by placing them directly into brine (a concentrated salt solution) where they undergo a natural fermentation. The olives develop a unique flavor during the fermentation when sugars in the fruit are converted to lactic and acetic acids. The fermentation also breaks down the chemical bond between oleuropein and sugars in the olive, allowing this bitter compound to be leached into the brine. Brine curing is simple and requires only water and salt for the initial washing and fermentation. However, the process takes at least 3 months and may take 6 months or longer, depending on the fruit variety and maturity as well as the temperature, salt concentration, and acidity (pH level) of the brine.
Green-ripe olives take longer to cure in brine than naturally black ripe olives. Instructions for two styles of brine-cured olives are included here. Greek-style black olives in brine are made with mature olives cured in strong brine over several months to reduce the bitterness. Sicilian-style green olives in brine are made with green-ripe olives that are cured in a batch of seasoned brine for 4 to 6 months. The salt is one of the preservatives for these olives, helping to reduce chances of spoilage and to ensure a consistent fermentation, so do not alter the brine concentrations given in the instructions below. You can safely store both styles of olive in brine for 1 year.