I use to fry potatoes reusing the same (olive) oil several times (about 5-6 times), and I salt them while frying. But the the oil doesn’t get salty. What’s the reason for that?
In: 2000
In addition to the science behind your question, two things from a culinary perspective:
Don’t fry anything using olive oil. Super low smoke point and it’s expensive. Try peanut oil or canola if you must.
Don’t add salt to oil when frying (to the extent that I’ll keep the salt content lower in a batter that is fried and apply finishing salt instead) as it will effectively spoil it.
Edit: I stand corrected. Olive oil is a good frying oil, albeit expensive ( .84/oz to .12/oz peanut oil with what I have).
The short and complicated answer is polarity.
The longer and more easily understood answer is magnets! A fundamental property of all molecules is polarity. Think of polarity as how “magnetic” a molecule is. Some molecules act as really strong magnets, like table salt, while others don’t act magnetic at all, like plastic. Every molecule falls on a spectrum between non-magnetic (non-polar) to extremely magnetic (polar). Molecules are like cliquey high schoolers in that they only want to hang out with other molecules who are the same as them: magnets with other magnets, and non-magnets with other non-magnets. The magnets and non-magnets wouldn’t stick together anyway as magnets only stick to other magnets (in this example anyway).
In the case of making fench fries, table salt is extremely magnetic while the cooking oil is completely non-magnetic so they don’t like to mix. Water on the other is a very magnetic so it is happy to hang out with the table salt all day.
Chemists take advantage of this magnetic (polar) property of molecules to do lots of fancy things in labs and industry but there are some real world examples that we deal with everyday besides cooking. If you were to splash your clothes with the hot oil while making those fries, it might be hard to get the stain out in the washing machine. As we have said, oil isn’t magnetic at all and water is, so they don’t like to mix. Soap is used as a intermediary between the two (soap molecules are giant with one side being non-magnetic and the other side very magnetic) but it isn’t a magic bullet as chemistry is complicated. So to get that stubborn stain out, you go to a dry cleaner. Dry cleaners use completely non-magnetic (non-polar) solvents (like tetrachloroethylene) instead of water to dissolve like minded non-magnetic (non-polar) stains from clothes, like the oil.
Hope this helps!
I think the real question here is:
How to you know the oil is or isn’t salty?
I thought everyone knows you salt fried foods after cooking. Most everything else during or before. Oh well salt is cheap
Why would you salt the fries before they’re out of the oil? That makes no sense at all.
The short and complicated answer is polarity.
The longer and more easily understood answer is magnets! A fundamental property of all molecules is polarity. Think of polarity as how “magnetic” a molecule is. Some molecules act as really strong magnets, like table salt, while others don’t act magnetic at all, like plastic. Every molecule falls on a spectrum between non-magnetic (non-polar) to extremely magnetic (polar). Molecules are like cliquey high schoolers in that they only want to hang out with other molecules who are the same as them: magnets with other magnets, and non-magnets with other non-magnets. The magnets and non-magnets wouldn’t stick together anyway as magnets only stick to other magnets (in this example anyway).
In the case of making fench fries, table salt is extremely magnetic while the cooking oil is completely non-magnetic so they don’t like to mix. Water on the other is a very magnetic so it is happy to hang out with the table salt all day.
Chemists take advantage of this magnetic (polar) property of molecules to do lots of fancy things in labs and industry but there are some real world examples that we deal with everyday besides cooking. If you were to splash your clothes with the hot oil while making those fries, it might be hard to get the stain out in the washing machine. As we have said, oil isn’t magnetic at all and water is, so they don’t like to mix. Soap is used as a intermediary between the two (soap molecules are giant with one side being non-magnetic and the other side very magnetic) but it isn’t a magic bullet as chemistry is complicated. So to get that stubborn stain out, you go to a dry cleaner. Dry cleaners use completely non-magnetic (non-polar) solvents (like tetrachloroethylene) instead of water to dissolve like minded non-magnetic (non-polar) stains from clothes, like the oil.
Hope this helps!
I thought everyone knows you salt fried foods after cooking. Most everything else during or before. Oh well salt is cheap
Why would you salt the fries before they’re out of the oil? That makes no sense at all.
Salt as other commenters have pointed out is what’s called an ionic compound. That means it’s made out of something like little magnets all stuck to each other. They aren’t actually magnetic but it’s a good analogy. Each atom of sodium and chlorine are independent of each other. They cling together as the solid salt crystal you see when you sprinkle it on your food. If you put salt into water however, the water is able to pry apart the little “magnets”, the individual atoms of sodium and chlorine. This allows the atoms to mix into the water evenly and when you touch the water to your tongue the sodium and chlorine atoms interact with your taste buds to create the “salty” taste. But if the salt is put into oil, nothing happens. it stays a solid and sinks to the bottom of the oil. If you taste the oil, there won’t be any sodium atoms or chlorine atoms free to interact with your taste buds.
Why would you use olive oil to fry potatoes?
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