<font color="purple">Senchick, I found a post that can explain somewhat of the difference between regular olive oil and the extra virgin. Preferably, the extra virgin is what most of us use for pre-shampoo treatments, for mixing with essential oils and to seal the ends for added moisture.
Hope to help out. Toodles</font>
<font color="blue"> Here is a breakdown of how olive oils are ranked. They are all "pure" olive oils, but the name is determined by whether or not it was a first, second, or third processing of the fruit and the acidity levels. Each time the same fruit is pressed, you get a lower quality of oil. The "oruja" is the last pressing and it cannot be considered olive oil because it uses solvents to remove it from the fruit. I'm not sure how the acidity levels affect hair, so it might just be a matter of personal preference which one you buy. But the taste of EVOO is probably preferred more than the others which is why it is seen on shelves more than the others.
HTH
Virgin Olive Oil
This oil is obtained only from the olive, the fruit of the olive tree, using solely mechanical or other physical means in conditions, particularly thermal conditions, which do not alter the oil in any way. It has not undergone any treatment other than washing, decanting, centrifuging and filtering. It excludes oils obtained by the use of solvents or reesterification methods, and those mixed with oils from other sources. It can be qualified as a natural product, and virgin olive oil can have a designation of origin when it meets the specific characteristics associated with a particular region. Virgin olive oils can have the following designations and classifications depending on their organoleptic (taste and aroma) and analytic characteristics (the degree of acidity refers to the proportion of free fatty acids, not to the taste):
Extra Virgin Olive Oil: Virgin olive oil with an absolutely impeccable taste and aroma; fruity; the acidity, expressed in oleic acid, may not exceed 1%.
Virgin Olive Oil:Virgin olive oil with an impeccable taste and aroma; fruity; the acidity expressed in oleic acid may not exceed 2%
Ordinary Virgin Olive Oil:Virgin olive oil with a good taste and acceptable aroma, whose acidity does not exceed 3.3%.
Lampante Virgin Olive Oil:Virgin olive oil with an acidity of more than 3.3% and/or whose organoleptic characteristics have defects. Not fit for direct consumption. Always refined.
Refined Olive Oil
This is obtained by refining virgin olive oils which have a high acidity level and/or organoleptic defects which are eliminated after refining. Their oleic acid acidity may not exceed 0.3%.
Olive Oil
This is a mixture of refined olive oil and virgin olive oil. Its acidity may not exceed 1.5%.
Olive-Pomace Oil
This is another oil derived from the olive that keeps its initial chemical structure. It is made of the oil extracted from olive pomace using solvents, which is then refined and blended with virgin olive oil. In no case may the degree of acidity exceed 1.5%. </font>
