My Cajun Classics 3 qt. cast iron pan after I cured it. Notice the silver/gray color before curing and then the shiny black patina after the cure.
Why cure the cast iron?
Curing a new piece of cast iron cookware (or in our case "roast ware") is very important. Curing is the process of allowing the raw cast iron to absorb a grease or oil which in turn protects the cast iron from rust, making it non-stick (not that we need that for coffee roasting) and ensuring a long life for your pan.
Here is How:
Place one oven rack in the middle of your oven and the other at the bottom. On the bottom rack place a cookie sheet or a few sheets of aluminum foil. Preheat your oven to 250F.
Scrub the pan with a scrubbing sponge (not iron wool) in hot soapy water. New cast iron is coated in a waxy material to prevent rust during shipping and while on store shelves. This must be removed before you cure the pan.
Thoroughly rinse the pan in hot water and immediately dry with a cloth or paper towel. DO NOT AIR DRY! It is critical to get the water off the raw iron. Raw iron is very susceptible to rusting.
Coat the pan and lid (if it came with a lid) with the vegetable shortening (Crisco) and put pan in oven upside down. This is so any excess oil will not collect in the bottom of the pan but will drain to the cookie sheet placed underneath the pan.
Let the pan cook in oven for one hour, then remove and let cool. While it is still warm recoat the pan and put back in oven. Raise oven heat to 350F and let cook for another hour. Shut off oven, leave the door shut and let the pan cool down slowly. Wipe the pan of any excess oil. Now the pan should be a brown caramel color, this is normal for a newly cured cast iron pan. Technically the pan is cured now (cast iron cure will blacken with use), however I like to take things a step further. Reheat the pan in a cold oven to 500F for as long as you can (a few hours or an afternoon) then let the pan cool down slowly again. Now it should be black and shiny!
That's all there is too it!