A seasoned cast iron skillet features a matte to slightly glossy black surface. It should feel slick and smooth to the touch, without any stickiness, flaking, or roughness.
To quickly tell if your cast iron is properly seasoned, look for a smooth, matte-to-slightly-shiny black surface and perform the water test: pour a little water into the pan—if it beads up and rolls off easily, your seasoning is solid.
For individuals with diagnosed iron deficiency or anemia, cast iron cooking alone is not going to provide enough iron, and additional dietary modifications or iron supplements may be necessary." It's also worth noting what type of iron you'll absorb from employing this material in the kitchen.
You never want the surface to be glossy and oily; if you can see oily traces on a finger swiped over the interior, there's too much—wipe it again. As you heat the pan to bond the oil to the surface, wipe it yet again to remove any oil that beads up.
Yes, cooking with cast iron pans can contribute to high ferritin levels. While safe for most people, the iron in the pan transfers into your food, and your body absorbs it. This effect is particularly significant for individuals with underlying genetic conditions or those who frequently eat acidic foods.
Avoid cooking highly acidic foods, delicate fish, strong-smelling dishes, and sticky foods (like eggs) in cast iron. These can strip your pan’s seasoning, leach metallic flavors into your food, or leave behind lingering odors.
These are the most common symptoms in the first 6 hours after ingestion.
A cast iron skillet is ruined primarily by rust from soaking or improper drying, warping from extreme thermal shock (like cold water on a hot pan), or cracking if dropped. While most seasoning issues are reversible, letting rust cause deep pitting, or fracturing the iron, destroys the cookware permanently.
Yes, you can absolutely use Dawn dish soap on cast iron.
Oil Residue & Splotchy Seasoning
How do you fix a badly seasoned cast iron pan? If you see some raised, splotchy residue on your skillet, which often looks like a spiderweb or spotted pattern, this is most likely some oil residue.
Iron deficiency occurs when your body lacks enough iron to produce hemoglobin, a protein in red blood cells that carries oxygen from your lungs throughout your body. When oxygen levels drop, you can experience a variety of physical and mental symptoms.
One serving of eggs (2x 60g eggs) provides 1.7mg of iron, which represents 14% of the Recommended Dietary Intake (RDI) for adults and 17.5% for children aged 9-13 years.
Cooking in a cast iron skillet can add anywhere from 1 to 7 milligrams (mg) of iron to your food per serving.
If you're just swiping a layer of oil onto the surface of your skillet, you're not seasoning your cast iron correctly. Seasoning involves a chemical reaction made possible through heat.
Preheat your oven to 450–500°F. Place aluminum foil on the bottom rack of the oven to catch any excess oil. Put your cookware upside down on the center rack. This helps prevent oil from pooling on the cooking surface.
A well-seasoned cast iron skillet features a rich, dark matte-to-slightly-glossy black surface. It should feel entirely smooth to the touch with no stickiness, carbon buildup, or rust. Visually, it can range from a deep, uniform black to slightly bronze or patchy as it builds layers from cooking.
Detergents aren't made with lye, so can't be soap. Either way you still shouldn't use soap with cast iron, but can use detergents, though there is no reason to do so. You can easily clean well maintained cast iron without it.
The best cast iron cleaner isn't a single chemical, but rather a combination of physical scrubbers and gentle basics like warm water or coarse salt. For seasoned pans, chainmail scrubbers and stiff nylon brushes are widely considered the gold standard, while enameled cast iron benefits from mild, mineral-based cleaners.
You can use mild, grease-cutting dish soap—like Dawn Dish Soap—or specialized cleaners to clean cast iron. The "no soap" rule is a myth stemming from harsh lye-based soaps of the past. Today’s mild detergents safely lift stuck-on food and grease without stripping the protective seasoning.
What Not to Cook in a Cast-Iron Skillet
Cast iron skillets can last a lifetime—and even last for generations when cared for properly. Because they are built from a single, durable piece of metal, they do not wear out like traditional non-stick pans. Even if a pan develops rust or loses its seasoning, it can almost always be stripped down and restored.
Soaking a cast iron skillet for a few minutes to loosen stuck-on food won't ruin it, but leaving it to soak for hours or overnight can cause significant damage. Extended soaks soften the seasoning layer and allow water to reach the bare metal, resulting in rust.
Iron is a mineral essential to life, but taking too much iron can cause severe symptoms, liver damage, and even death. Symptoms develop in stages and begin with vomiting, diarrhea, and abdominal pain. Liver failure can develop days later.
Bloody or black stools, or rectal bleeding. Bloody or pink urine.