All techniques aim to ‘cure’ or de-bitter the olive by removing the very bitter component in the raw olive, called oleuropein. This bitterness is water-soluble, so this means we can use changes of water to cure them. Other techniques use brine (a salt solution), dry-salting or lye (caustic soda) – AND time. Olives are the ultimate in ‘slow food’, as the curing can take up to a couple of years, depending on technique, maturity and size of olive.
Once cured, the olives can be consumed as they are, or ‘dressed’ (flavoured with garlic, herbs etc); or need to be preserved for long-keeping. Usually brine is involved for preserving, on its own or combined with vinegar.
Sele – this is dried in a basket of rock salt, which draws all the water from the olive. The longer the olive is left in the salt the firmer the olive becomes. The olive can lose up to half its original weight during curing, giving a crinkly effect. This is a dry store olive and is the least salty tasting.