Seasoning cast iron helps to fortify the iron itself, as well as keep its surface slick and rust-free. It is advisable to always store cast iron pans with a slight coating of oil on it, but seasoning it properly requires attention, time and heat. Grapeseed oil is considered one of the healthiest oils due to its source, which is the seeds from grapes found in pomace, the leftover sediment produced after wine-making has occurred.
Preheat your oven to 350 F.
Warm the cast iron on your stovetop on low heat.
Pour a minimal amount of grapeseed oil into the pan. A pool the size of a quarter is typically just right.
Heat the oil for 1 minute on the pan so that it becomes more viscous.
Spread the oil evenly all around the interior walls and bottom of the pan. It is advisable to also coat the outside, underside and handle of the pan for maximum protection.
Place the pan in the preheated oven and allow it to bake for 1 hour. The pores of the cast iron will open during this process, and the oil will enter the iron.
Turn off the oven and allow the pan to cool completely before removing it. The pores of the iron will close and seal in the oil.
Season the cast iron as often as possible. Doing it after every use is ideal. This will help the pan retain its best qualities.