Welcome to brain Stuff from house Stuff Works dot Com where smart happens him Marshall Brain with today's question, how do they make olive oil or where does olive oil come from? Most people come into contact with olives in one of three ways. There are the olives that go on pizzas and into dinner entrees. They either come fresh or they come from a can. Second, there are the olives with pimientos that go into martinis. And then third there's olive oil. Now, in my case, there was a
fourth way. When I was a kid, I grew up in Huntington's Beach, California, which is in southern California near l A, and we lived in this little subdivision that the developer had planted an olive tree in the front yard of every house. So when I was a little kid, these olive trees would produce olives every year and we would have olive fights with them. So the fourth way
to experience olives is through olive fights. But ignoring that it seems odd, but olives, whether you're having fights with them or buying them at the store, have oil in them. Not only do the seeds have oil in them, like all seeds do. Like sesame seeds and soybeans and corn, they all have oil in them. Olive seeds have oil in them, but also the fleshy part has olive oil
and its cells as well. So to make olive oil, what you have to do is you have to release the oil from the cells of the flesh as well as the cells from the seed. Or if you're making a really high end boutique olive oil, you take the seeds out and you just get the oil from the flesh. So the first step in making olive oil is to go out to your olive orchard which you've planted somewhere,
and harvest the olives at just the right time. You don't want them to be too unripe or you get acid e kind of olive oil, and you don't want to be too ripe or you get disgusting olive oil. You want them to be just the right level of ripeness. You harvest those olives, you could either rake them out of the tree, or you can climb up in the tree and hit them with your hands or um. You know, maybe there's a mechanical shaker like they use on some nut trees, though I doubt olive people would be the
sorts to use mechanical shakers. So you harvest these olives by knocking them out of the tree into some cloths that you've spread on the ground. Then you wash the olives and separate out as many of the leaves as you can, and now it's time to crush them. So the old fashioned way to crush them is to take giant granite wheels. So think about the wheel on your car. It's on an axle. There's the wheel and the rubber is hitting the road. Well, imagine making that wheel out
of granite. But now imagine making it immense, say four or five feet in diameter, so it weighs about a thousand pounds, and you put it on an axle with another big granite wheel on the other side, and you spin them in a tub that you've filled with your olives that you want to crush. So you're going to drive over these olives with your giant, thousand pound granite wheels for about a half an hour and you're gonna mash that set of olives up into a paste. Now
that's one way to do it. The other way to do it is with some kind of mechanical shredder kind of thing that uses blades to finally chop up the olives. But either way, what you're getting is this paste that consists of the olive flesh as well as the olive seeds, all ground up and finally minced. You take that and you need to let it sit for about an hour. So let me pause for a second here. As I'm recording this, there's someone listening in the background and a
question has come in. The question is what does an olive seed look like? Because usually when you get olives, the seeds have been removed. Now, if you have olive fights with all of these little kids, you see the seeds all the time. That's the best part. So this seed is sort of like a miniaturized peach pit. It's very hard, like a peach pit is, and it's just one of them at the center of the olive. And to make an olive with pimentos, a push that seed out and put a pimento in its place, and that's
why you never see the seeds anyway. So now you're paste has been sitting for a half hour or an hour, and the oil has had a chance to kind of separate out and develop and it's time to extract the oil. You do that in one of two ways. The old fashioned way is to put the paste in a press and to apply a lot of pressure hydraulic ly to force the oil out, and you have your olive oil.
The more modern way is to put the whole blob of paste and a little water into a centrifuge and spin it up and it separates, so you get this seedy kind of stuff on the outside of the centrifuge, then the fleshy kind of stuff, the water based stuff in the middle, and then in the center of the centrifuge you get the oil because it's the lightest thing in that package. And presto, you have olive oil. It's ready to be put in a bottle or a can or wherever it's gonna get put so it can be
shipped to you. Now, when you go to buy olive oil at the grocery store, you've seen these designations. There's virgin olive oil and extra virgin olive oil, and olive oil, olive oil and refined olive oil. What's the difference between all these different kinds. Well, the difference between virgin and extra virgin has to do with acidity. So both of these things have been processed using the process we just
discussed where you crush the olives. You don't heat them up to a high temperature, you don't use any chemicals for oil extraction. You just crush them, you let them sit, then you press or centrifuge the oil out of it. Either way you're gonna get virgin or extra virgin olive oil, but the differences based on the acidity. The lowest acidity gets called extra virgin olive oil. If it's higher acidity, it's virgin olive oil. If it has too high of acidity, you can't call it either, and you have to do
something else with it. And in that case you might send it through some kind of process or blending to try to bring down that acidity level. And then there's also what you can do after the facts. So with that paste you have left over, there's still some oil left in it, you might try to extract olive oil from that using heat or chemicals, and then that's just plain old olive oil or refined olive oil, probably not
used for cooking, but used for something else. Now, having learned all about olive oil, I will tell you one thing that kind of disappoints me. And that's the fact that in this subdivision there were hundreds of houses, which meant hundreds of olive trees and thousands of pounds of olives. In all likelihood, if we had been really industrious as children, we could have collected up all those olives and started
our own olive oil press. But I guess, for one thing, people in America maybe weren't so interested in olive oil when I was a kid. In second we weren't quite that industrious. So until next time. For more on this and thousands of other topics. Does that how stuff works dot com and don't forget to check out the brain stuff blog on the house stuff Works dot com home page. You can also follow brain stuff on Facebook or Twitter at brain stuff hs W. The house Stuff Works iPhone
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