Seasoning isn't a greasy coating left behind from not properly washing a pan, and it's definitely not flavor built up over years of use. Instead, it's a protective coating made by burning oil onto the pan. Here's how to do it properly with carbon steel.
Bare carbon steel will rust if exposed to moisture and humidity; seasoning acts as a barrier to water, preventing the pan from rusting on a humid day.
Step 1: Remove Protective Coating and Wash the Pan
Most carbon steel pans come unseasoned, with a protective coating that ensures the bare metal doesn't rust. How do you know if your pan is unseasoned? It'll be a metallic grey color, and not black like most off-the-shelf cast iron pans.
Our Spun steel pans come with a coating of mineral oil
Step 2: Dry the Pan
As soon as you've removed the protective coating and washed the pan, you need to dry it right away: The stuff that was preventing your pan from rusting is gone and you'd be shocked by how quickly a light coating of rust can form on bare, wet steel.
I usually give the wet pan a quick towel-dry, then set it over a stovetop burner to cook off any remaining moisture. This also happens to lead us right into the next step: heating the pan.
Step 3: Heat the Pan
It's time to apply the first layer of seasoning, and it helps to heat the pan first so that the oil can go on as thinly as possible. I often do this over a burner but you can do it in a 450°F oven.
Step 4: Apply Oil Sparingly
Applying oil to a kitchen towel, for seasoning a carbon steel or cast iron pan or wok
Lightly grease a kitchen towel that you don't mind ruining with a neutral oil. Canola oil, vegetable oil, and grapeseed oil all work. What you don't want to use: lard and shortening; butter, which has water and milk solids mixed into it; olive oil, which is more expensive and often has sediment; or flax-seed oil, which makes for beautiful looking seasoning that's more prone to flaking off.
Rubbing oil all over a carbon steel pan to season it
Now rub that oil onto the pan, inside and out, making sure to buff away any excess until the pan looks dry. I can't stress this point enough: A heavy hand with the oil will mess up your seasoning, leaving you with a splotchy, sticky coating that can be difficult to fix. If you so much as wonder if you might have applied too much oil, I can guarantee that you have.
Buff it out, buff it dry, buff away any trace that you've oiled that pan at all. Don't worry, there's still oil there, and it's just enough for seasoning.
Step 5: Burn it On
Now let the oiled pan heat, either on the burner at its highest setting or in that hot oven. The burner works well, but because carbon steel doesn't conduct heat well, you may need to move the pan around to ensure the oil has formed a polymer everywhere. How can you tell? Well, with new carbon steel, you can literally see it. The areas where the oil has set into a solid coating will have turned a faint shade of brown. That's the seasoning!
Beware, the pan will smoke heavily during this process, so open your windows, turn on your fans, and send your kids out to play.
The smoking will eventually stop, which is a sign that the coating of oil has completed its transformation. How long this takes over a burner depends on the burner's heat output and the size of the pan, but it can be several minutes. In the oven, about 30 minutes should do it.
Step 6: Repeat
Continue applying those micro-thin layers of oil and heating them until they darken, over and over, until the pan is, at the very least, a dark shade of brown. That should be enough seasoning to start.
Step 7: Use the Pan and Re-Season as Needed