For many years now I have used olive oil. I bake with it and fry with it. I use it to fry my donuts. I use it in my deep fryer. But someone told my husband that using it in your deep fryer is poisonous, which I had a hard time believing but it kept bugging me so I finally took the time to look it up so I could be convinced I was right. Thank Goodness. By the way many people commented on the good taste of the fries. When the oil gets dirty I just throw it away and add new. ( I buy Kirkland Signature at Costco.) Do you know if it is processed properly and those kinds of things?
I'm glad you did not fall for the urban myth about frying with olive oil, it flies in the face of common sense considering that olive oil has been used for frying for thousands of years, long before there were such things as canola and corn oil.
As to the question about the Costco oil, label laws in the U.S. do not conform to international standards so it is hard to know if an olive oil labeled as extra virgin is actually high quality. One plus is that large chains like Costco which private label their oil have more to lose if the product is found to be defective than if another brand they sell is involved in a scandal. I have seen the Kirkland olive oil brand used informally in several olive oil tastings here in California and it was found to have good taste for the price.
The small amount of olive oil made in the US and marked with the COOC seal has been extensively tested and is genuinely high quality.
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