It’s funny but food sticks to stainless steel because it is both too smooth AND too porous.
1) it’s too smooth for oil to bond to it properly and create a smooth polymer layer of seasoning over time (like cast iron or carbon steel do)
2) it’s porous enough for food to fall into microscopic divots in the surface and get stuck there
people claim you can season stainless steel (e.g. as described here https://www.heritagesteel.us/pages/cooking-techniques) but IME stainless steel is sticky no matter what you do, so I stopped using it for anything except soups, stews, pasta water, etc.
Stainless steel means *stainless*, not *non-stick.* You have to learn how to cook on it in order to make sure the food doesn’t stick. This means using either sufficient water or sufficient fats while you cook, and really watching your cooking temperature (too high of a temp increases the chance of sticking). And it will still stick, despite all that, because it’s not a non-stick pan.
I understand cast iron. I have never made things not stick to stainless steel.
I get the Physics of it. That I can explain. The stainless steel is still “porous”. That means it has tiny holes in it. Food sticks because bits of the food seep down into those holes. Imagine sticking your fingers in a bowling ball. The food does that.
Supposedly if the steel is “hot enough” the pores are supposed to be too big for food to stick well. And supposedly the chemical reactions that happen after food is cooked are supposed to cause it to “release”. So if food is sticking, it implies the cookware wasn’t hot enough and the food was not finished cooking.
In practice? I find food just sticks to it. Maybe you need high-quality chef-grade stainless steel. But it seems to me like a lot of chefs use carbon steel instead, which takes seasoning layers much like cast iron. That means they literally *burn* oil onto it until the oil fills the pores and turns into a layer sort of like a varnish. No pores means the food can’t stick. Stainless steel’s pores can’t do that. They’re too big for the oil to “stick” and form a seasoning layer.
preheat pan with no fat, wait until water beads instead of evaporating, add fat, immediately add food on top, try to size the pan so it doesn’t cool too much from the food you put in, so ensure the food has had time to sit at room temp, not out of the fridge, and don’t overcrowd the pan, you want to avoid the temperature plummetting when adding food. then just wait for browning, flip once. don’t run the pan on high or low. too hot will burn, too low will stick. clean with barkeepers friend or a little baking soda as an abrasive.
LEAVE THE FOOD ALONE! IT WILL UNSTICK WHEN IT’S READY!
Hot pan, plenty of oil, and just leave it the hell alone. Using a stiff metal spatula and a good amount of downward pressure, try and release the food. If it doesn’t release, wait a little longer. I cook fish and eggs just fine this way; it just takes a little getting used to. It also gives the best crispy crust – even better than my cast iron
Yeah, that happens. I don’t want to invoke too much esoteric chemistry, here. In short the pan has a thin layer of chromium oxides on it’s surface that form as a reaction of chromium in the steel with oxygen and moisture. This layer is highly inert, unlike iron oxides, so it seals the surface and stops further oxidation, like a coat of paint, but better.
However the oxygen atoms bonded with chromium have a negative change. That causes water molecules and particularly proteins which have some positive charges, to be attracted to the negative oxide layer. Likewise the chromium atoms have a positive charge so they attract negatively charged oxygen atoms in water.
Another thing that happens is mechanical adhesion where liquids flow into small scratches, valleys, and divots in the surface, then cooking causes the liquids to solidify or dry out. This locks the two materials together like jigsaw puzzle pieces. Eggs, for example.
Nonstick pans typically have a coating of a slippery plastic called poly-tetrafluroethylene or PTFE. PTFE has a lot of cabon-fluorine bonds which are generally the second strongest bonds on nature, second only to the bonds in graphite. This causes it to be very repellent to liquids. Any molecules with charged regions like water actually experience a slight repulsive force from PTFE whether positive or negative. Thus liquids simply skate around on top of the PTFE layer and have little physical contact due to surface tension. More specifically there’s typically a layer of gases and molecules called hydrophobic surfactants (mainly fatty acid derivatives) that form between the PTFE layer and any water based liquids. This stops both chemical and mechanical adhesion. Although older pans where the plastic layer has been heavily scratched and scored may still experience mechanical sticking of foods.
Now, cast iron pans typically have the granddaddy of all nonstick coatings. Usually they’re sandblasted in order to actually increase surface roughness and porosity. This is because iron can act as a catalyst which causes certain vegetables oils (specifically those with poly-unsaturated fats like soybean oil) to polymerize by forming lots of *cross-links* with oxygen. This causes the oil to solidify into a soft, flexible, oily, gel with a brown color. These days it’s usual for the factory to sandblast then coat the parts with food grade flaxseed oil, poppy seed oil or soy oil. The the pans are baked for several hours to speed the “drying” of the oil coating.
This prevents sticking due to the normal repulsion of water and oil. With cast iron
You could in theory season a stainless steel pan in the same way. Although you’d be wise to either sandblast or heavily scuff the inside surface with a power sander and a scotch-brite pad. The point of this would be to increase the adhesion of the oil coating so it didn’t flake off.
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