OLIVE OIL FAQ
Is oil made from green or black olives?
All green olives eventually go black. The olives in Spain are mostly green in mid November but by January almost all of them have turned black.
Is olive oil made from the stones or the flesh of the olives?
The oil in olives is concentrated in the flesh not in the stones. After milling, the stones are mostly intact. Stones do not make any distinctive contribution to the flavour of the oil and in some extraction techniques the stones are removed.
What is the difference between virgin and extra virgin olive oil?
Extra virgin olive oil is the highest quality and most expensive. Extra virgin olive oil must be extracted using only mechanical means without the addition of any solvents and with a temperature of less than 30C.
Extra virgin olive oil must have less than 0.8% free fatty acid because better oils have a low acidity. Each time an olive producer takes a load of olives to the mill, a random sample is taken and this is analysed in a laboratory. The acidity influences the amount that is paid for the olives.
Extra virgin olive oil must have a peroxide value of less than 20. The peroxide level is an indication of how much oxidation has happened, all oils oxidise but excessive oxidation results in rancid flavours.
In order for an oil to qualify as “extra virgin” the oil must also pass an official chemical test in a laboratory and has to be evaluated by a trained tasting panel recognized by the International Olive Council.
What is the basic process of olive oil extraction?
First the olives are ground up into a paste. This was traditionally done with 3 massive heavy conical stones which were dragged around in a circle by a donkey. One of the cooperatives where we take the olives uses a more old-fashioned technique (click here for more info). Nowadays, the olives are ground up using electric motors. Traditionally the olive oil paste was then spread out on circular mats which were stacked in a press and pressure applied to squeeze the oil out of the paste. Pressing the olive paste would now be considered an old-fashioned technique and nowadays most oil is extracted in centrifuge-based systems.
Can I use olive oil for frying?
Olive oil is versatile and can be used for roasting, sautéeing, shallow frying, dressing and drizzling. Since it has a high smoking point (210ºC) which is higher than the ideal recommended frying temperature of 180ºC for most foods, it can also be used for deep-fat frying and many chefs recommend it.