Not all olive oils are made equal - their quality is in essence, graded based on production method, acidity level and flavor.

Although different grades of olive oil can mix together to create other grades and types, there are 3 principal types of olive oil purposely made to benefit your health more than others, which you ought to know. Let's run through their production processes briefly to help you get some basic ideas and make a better decision on which one you should go with for best health benefits.

How is Olive Oil Made - the Actual Manufacturing Process

Harvested olives will first go through grinding and pressing using heavy granite millstones or modern stainless steel rollers to extract the oil. At this point, they never add any chemical so as to preserve its nutrients, aroma and flavor. In essence, the full nutritional values and health benefits of olive oil retain.

You need to use "cold pressing" to make top quality olive oil. It means the frictional heat emitted during pressing and grinding should not exceed 86 degrees F (i.e. 30 degrees C). Exposing the oil to temperature above 86 degrees F can run the risk of losing its nutritional values too.

Such "cold pressing" extraction method yields grades of extra virgin olive oil or virgin olive oil depending on its acidity level. The lower the acidity level, the better the quality and type, and thus, the greater nutritional benefits for your health.

Manufacturers further process some virgin olive oils after first chemical-free pressing, especially when they bear poor flavor and an acidity level of more than 3% (i.e. not fit for human consumption anymore). They then send the acidic oil for refining to reduce its acidity level so that it can be re-used for consumption again.

But because this type of refined olive oil is produced in presence of high temperature, chemicals, and filtration, their quality will drop dramatically in terms of flavor and nutritional value.

Refined oil usually bears no color, odor and flavor, thus they're often blended with virgin or extra virgin oil to make it look and taste better. This mixture forms another grade called pure olive oil in some places.

This pure olive oil can also be further chemically processed to form another 2 types called olive-pomace oil and lampante oil. But we're not interested in them here since they don't benefit your health much, especially lampante oil, which is totally inedible.

Now you know how olive is made, and this will help you choose the right type of olive oil for your health benefits and dietary needs. I personally go with extra-virgin olive oil and add it to salad, smoothies or any meals without heating because as just mentioned, heating can degrade the oil's quality and its nutritional values.

But if you prefer to serve your hot food with olive oil, I suggest that you only add the oil just before you're ready to eat the food so as to preserve its nutritional benefits for good health.