Can a poor cast iron seasoning affect the sear?

Question

I purchased a lodge cast iron exactly one year ago and after a seasoning it once was able to cook dozens and dozens of perfect steaks throughout the year. I never had any trouble cooking or getting a sear, sous vide or conventionally cooking. Typically when I cook I use avacado oil and allow the pan to heat up for 2-3 minutes before putting the meat on.

However, after messing up a re-season (causing some sticky spots on the cast iron), it's like I've lost my ability to cook. No matter what I do, the steak won't sear or cook even if I leave it on there for 4 minutes. It burns my cajun seasoning (which can withstand the heat from a grill which makes no sense to me), and it consistently drips oil into the flame as I cook. I'm considering just buying a new cast iron, because I tried scrubbing off the old seasoning with steel wool and brillos to no avail.

What is happening here? My only explanation could be that the poor seasoning on the cast iron is preventing proper heat transmission. It's frustrating that I have to overthink how I cook steaks when before I would simply heat up the pain, apply oil, wait 30 seconds, and get that perfect sear every time. What is the problem here?

Answer 1

"Burns the Cajun seasoning": well, sure. Spices are going to be burned by direct heat from cast iron. I'm not sure why you didn't notice this with the "old seasoning" -- perhaps you're cooking at a different time/temperature profile -- but if you're putting a sear on a piece of meat, it should not have a dry rub. (Grilling meat is more compatible with a dry rub, because the rate of heat transfer is much lower so the rub is evaporatively cooled and doesn't get as hot.)

"Drips oil into the flame" -- that seems weird to me. Where is it getting the oil from? Are you oiling the bottom of the pan before cooking?

I don't think there's anything wrong with your pan. Sticky spots indicate incompletely polymerized oil, and will sort themselves out with time. They also probably indicate an overly thick layer, which will also sort itself out with time. The number one mistake people make with cast iron pans is worrying about polymerization and whatnot, anxiously stripping and scrubbing and painstakingly layering six coats of oil. Just keep cooking with it, clean it properly, and the seasoning will sort itself out.

I should mention that I have no direct experience with avocado oil, and it's possible that its weirdly high smoke point is associated with poor seasoning properties. Cooking with a "normal people oil" may help.

Answer 2

"Poor seasoning" isn't seasoning at all, cooking with poor seasoning will ruin your food two ways: 1. It's already partly plasticized oil which, on its own, tastes terrible. With a little heat and moisture, it will come off the pan and stick to your food and 2. If there's insufficient seasoning below the recent job, the food will stick, and stuck food burns. Any caramelization that develops with a good sear will remain in the pan rather than on the steak. With only #2 to worry about, I've salvaged a few batched jobs by making a good pan sauce if I can rescue the job before the sugars turn from brown to black.

Cast iron is a highly contentious subject, yet the goal is always one: a perfect workaday seasoning. If I had to guess, you're dealing with one of the below problems:

1. One of the most prevalent myths you find on the Internet is that a well-seasoned cast iron looks "glossy". The other one being that one needs to strip down to bare metal to get a good bottom-up seasoning.

2. The pan isn't actually clean before you layer on oil and bake to form a hard shellac-like seasoning layer

3. Your heat and oil usage when cooking is off.

To remedy all of these, I would follow the Tasty blog cast iron seasoning instructions (link forthcoming). Give your pan a wash with a liquid dish soap all over. Scrub off any caked-on food, carbon, or loose seasoning using a metal spatula. Dry the pan on the stove with heat, once cooled, rub canola(rape)/safflower oil all over, then (critical) wipe off with a paper towel - whatever sticks to the pan is all you need. Bake at 350F/185C or similar for like an hour then allow to cool in the oven.

When you cook steak, the pan does not need to be blistering hot - despite what Gordon Ramsay says - just hot enough for oil to shimmer and the steak to sizzle as it goes in - we are avoiding burning food in our pan after all. Once finished you can either make a pan sauce or not, and then scrape out the remainder with a spatula, and wash with dish soap, allow to dry, and just rub around the pan with a bit of oil.