Funny, I actually go over the smoke point to polymerize. I use ghee and cook at 525 for 1 hour, repeating the process for additional layers. It makes beautifully smooth and hard finishes.
Literature on the subject has been highly contradictory in my experience. Some argue that the oil or fat should be below smoke point, and others say it should be over. I personally avoid Crisco, vegetable oil and seed oils in my cooking and I extend that to seasoning as well.
Ghee has worked fantastically for me but it’s another case of he-said-she-said, with half the internet thinking it is the perfect cooking and seasoning fat, and the other half decrying it for a higher rate of spoiled or rancid seasoning — issues I’ve personally yet to come across. Everyone’s mileage varies so much with cast iron, doesn’t it?
A true seasoned surface will only form properly at temperatures well in excess of the 350-375 degree F temperature that some manufacturers recommend for seasoning cast iron. Low temperatures do not completely polymerize and break down oil and will leave a brown, somewhat sticky pan instead of a black, non-stick one. 400-500 degrees F is the effective range for seasoning.
From Dave Arnold’s excellent blog ‘Cooking Issues’
I always thought you were supposed to go over the smoke point, but I did a bit of reading recently and found one source that sounded confident that staying below the smoke point still results in polymerization. There was also conflicting information on the actual smoke point of shortening, anywhere from 490-525F. So far 470 is working well, but whether the seasoning is durable long term is yet to be seen.
There’s still a “smoking oil” smell in the kitchen so I leave the fan running, but there’s no visible smoke. I think with the oven set to 470F, there’s probably enough radiant heat from the oven coils to bring the iron up to 490+, at least for a little bit. That’s just an unscientific guess, though.
Funny, I actually go over the smoke point to polymerize. I use ghee and cook at 525 for 1 hour, repeating the process for additional layers. It makes beautifully smooth and hard finishes.
Literature on the subject has been highly contradictory in my experience. Some argue that the oil or fat should be below smoke point, and others say it should be over. I personally avoid Crisco, vegetable oil and seed oils in my cooking and I extend that to seasoning as well.
Ghee has worked fantastically for me but it’s another case of he-said-she-said, with half the internet thinking it is the perfect cooking and seasoning fat, and the other half decrying it for a higher rate of spoiled or rancid seasoning — issues I’ve personally yet to come across. Everyone’s mileage varies so much with cast iron, doesn’t it?
From Dave Arnold’s excellent blog ‘Cooking Issues’
https://cookingissues.com/2010/02/16/heavy-metal-the-science-of-cast-iron-cooking/
I always thought you were supposed to go over the smoke point, but I did a bit of reading recently and found one source that sounded confident that staying below the smoke point still results in polymerization. There was also conflicting information on the actual smoke point of shortening, anywhere from 490-525F. So far 470 is working well, but whether the seasoning is durable long term is yet to be seen.
There’s still a “smoking oil” smell in the kitchen so I leave the fan running, but there’s no visible smoke. I think with the oven set to 470F, there’s probably enough radiant heat from the oven coils to bring the iron up to 490+, at least for a little bit. That’s just an unscientific guess, though.