I have an irrational attachment to cast iron cookware. It is not the best material to cook with, to clean, or to own. It takes preparation and care. Every time that you move house, you wish that you’d invested more heavily in aluminium. Dropping them results in either cracked tiles, destroyed pans or foot injury.

Compared to copper, it’s a poor conductor of heat. Harold McGee tested pans a few years ago over at the New York Times and, despite the feeling that the weight of a cast iron pan lends an even heat distribution, this proved to be wrong:

The heavy copper and the light aluminum pans produced evenly toasted heat maps. The stainless-clad aluminum did pretty well, too. But the cast-iron pan scorched a small area, and the pattern was familiar. For years, I made risotto every week or two in my favorite enameled cast-iron pot, and always found a solid brown ring of stuck rice grains right above the flame.

Still, I was surprised, because I’d always heard and thought that cast iron was a slow but even conductor. I wondered if it would perform better if I heated it more gradually over a low flame, or on an electric heating coil, which would contact more of the pan bottom than the gas flame. I was wrong. The low flame caused even browning over a small area at the centre of the pan, and none elsewhere. The electric burner gave a pattern much like the flame’s.

When I spot-checked the cast iron with my thermometer, there was a consistent 100-degree difference between the pan centre and an inch from the edge. That’s easily enough to make the difference between browning and scorching. My cast-iron pan makes a much better potato galette in even oven heat.

Unlike other cookware, cast iron lasts. It’s probably the only piece of cookware which, if a modicum of care is taken, you’ll be able to cook on for hundreds of years. A cast iron pot from the 1800s is as likely to function as well as one made last week.

Apart from dropping it, the only thing that can go awry with cast iron is letting it rust away. Left to its own devices, a cast iron pan will corrode due to oxygen and moisture in the air. Iron is relatively porous and requires “seasoning” – building up an artificial protective layer by baking the pan at a high temperature with oil. Oils that are high in omega-3 fatty acids work best to form the hard, protective polymer across the surface of the pan.

Traditionally, lard was used to season cast iron because a hundred years ago, pork was higher in omega-3s, which is still the case today if you can get hold of fresh lard from a free roaming pig. Don’t be tempted to use lard from your quality Spanish jamon, because the salt can damage the pan. By far the best modern substitute is flaxseed oil – Sheryl Canter has a good rundown of the science over on her blog.