An excellent article on keeping your knives in order by Chad Ward.
Cast iron and carbon steel pans are ‘seasoned’ with a smooth protective layer of polymerised oil to stop them rusting and make them non-stick. To create this layer you heat a refined neutral pH vegetable oil with a moderate smoke point in them until it polymerises and goes hard. Suitable oils are canola or rapeseed (225’C), rice bran (230’C) and grapeseed (215’C).
Stripping and preparing a pan for seasoning
Sometimes you need to start again. The seasoning may be rough, flaking or sticking. As a minimum you want to get the cooking area back to a smooth raw metal surface. Here are some options.
- Cover with heavy duty oven cleaner and leave 24 hours (alkali).
- Partially fill with vinegar for an hour (acid). This works well for mild seasoning.
- Cook a tin of tomatoes directly in the pan for 30 minutes (acid).
- Sand with water and wet&dry sandpaper 400 grit then 800 grit. This takes a while but gets back to bare metal.
- For any metal pan or grille without non-stick coatings or painted finishes put them in a domestic oven and turn on the high temperature “pyrolytic” cleaning function for an hour. This will nuke everything off the pan – fantastic!
Wash with water and detergent, rinse, dry with a cloth and heat on the stove to dry out completely. Now you can season.
Cast iron has a relatively high carbon content and a rough surface from the casting process. It seasons easily and holds a durable surface.
To season wipe the pan with the thinnest layer of oil you can and put in an oven upside down heated from cold to just below the smoke point for the oil for an hour. Take out and allow to cool for 15 minutes. Repeat this as many times as you need to get a thick layer.
Do not cook with lots of sugar or tomatoes for prolonged periods of time as it can affect the oil coating.
Do not leave food to stand in cast iron pans. Clean immediately after cooking, don’t soak for long periods of time. Preferably just use hot water but detergent is ok (if the seasoning can be removed by detergent then it is failing and needs to be re-done). Dry thoroughly after washing. Wipe with a drop of oil if the surface looks dull before storing. To really look after it wipe the surface with oil and place on a high heat til just below smoking. This will top up the seasoning.
Black steel; also known as carbon steel
Carbon steel pans have a smooth surface. This makes the seasoning more fragile than cast iron.
Seasoning of raw pans
See stripping and preparing above. Put 10 mm of oil into the pan and heat on high until the oil starts to smoke. Pour out the oil carefully and reserve for further use. Wipe the pan dry with paper towels and leave out overnight. Sprinkle a teaspoon of salt in the pan, heat again, and rub vigorously for a moment with paper towels to remove any sticky bits, rub pan clean.
Cleaning and care of a seasoned pan
Wash with hot water and dry thoroughly. Now and again scrub gently with steel wool and scouring powder or salt, rinse and dry it. Heat for a minute or two until the bottom is too hot for your hand. Rub with a paper towel and oil and let it stand overnight. Clean with salt as for seasoning above.
How to cook in a carbon steel pan without sticking
Pre-heat the pan over medium-high heat for 2 minutes. Put in your oil or butter, swirl around the pan and allow it to come to temperature. Remove from the heat for a minute. Now place back on your desired heat level and put food in the pan.