Evaluation Criteria for Oil
The acidity is expressed either in grams free oleic acid per 100 gr fat ( acidity ) or as numbers acidity gives the thousandths of KOH required for neutralization of free fatty acids present in one gram of oil.
The link that connects these two expressions (acidity – acid number ) is : acidity ( oleic ) (% ) = number of acidity x 0,503
Balanced acidity, olive oil, divided into edible (acidity up 3.3 %) and industrial (acidity greater than 3.3%)
How to choose the right oil
Moisture , mists and dregs become rancid and bitter olive oil. During winter , may be formed on the bottom of the bottle and suspensions or white precipitate , which however normal.
Choose olive oil of low acidity (0-1 %).
The color of olive oil should be between golden and light green or dark green. Olive with whiter color is good to avoid , unless their nature is more yellow , like those coming from Lesbos . Avoid oils that are exposed to light and moisture .
The storage conditions significantly affect its quality.