I know this sounds like a joke/troll thread, but its not.

What viscosity would a typical cooking oil be, or be 'equivalent to'?

I was making some eggs the other day, and took our bottle of vegetable oil out of the fridge. The fridge is probably about, what, 3-7 degrees C? The oil pours easily out of the bottle. It got me thinking: This oil probably doesn't stop pouring until about -10 to -15 degrees C, so it would be equivalent to about a 20W oil, or something like that. Obviously, as you heat the oil, it thins, so what viscosity would it be at 100C? Would it be like a 20W-30? 10W-30?

I know they 'hydrogenate' oil to make it 'useable' as food; is this similar to 'hydrocracking' a petroleum oil, to give it better viscosity characteristics? Forgive me if this is a really, really dumb question!

Corn oil is 8.6 cSt at 100C, so like a 20 weight.

Viscosities of many substances.

Vegetable oils have different freeze points depending on the amount of saturated fats and monounsaturates. Olive oil will freeze to a wax like substance in the refrigerator, while oils with a lot of polyunsaturates like corn oil will not. The VIs of vegetable oils are very high, often near 200, but they are not very oxidatively stable due to their unsaturated acids.

Mild hydrogenation of vegetable oils will lighten the color. If you hydrogenate it more you will raise the freeze point by increasing the level of saturates and monounsaturates. Raise the freeze point above ambient and you have margarine or shortening. Hydrocracking is much more severe.

BTW, you should keep your refrigerator below 38F (3.3C) to inhibit the growth of botulism spores, although such an occurrence would be very very rare. The colder the refrigerator, the longer food will last.

Tom NJ

And the colder the better for those Bud Lites...

Hydrocracking petroleum oil yields a good base for lubricating oils.

Hydrogenating vegetable oils yields fats that are not so good for the human body. Better to eat butter if you want it saturated.

You already knew that. But the medical establishment told you the contrary for decades, only acknowledged their folly a few years ago.

Food processors often choose their oils (additives ) for characteristics mentioned above, such a resistance to waxiness when cold, or they hydrogenate the oil to give the final product a desired texture/feel. But above all, and understandably, price drives their choice.

The price of vegetable oils at the grocery store doubled less than a year ago. I've been waiting for it to ease down a bit, but it hasn't.

You already know all that, so I'll stop.