Wok patina comes off

Question

I got a flat-bottomed iron wok a few weeks ago at a local Asian supermarket. I seasoned it on my electric stove, based on information I googled up: heated it up, put a thin layer of peanut oil on it, turned the heat down and let it sit for 15 minutes. This worked pretty well and formed a nice dark layer, but even after cooking in the wok a couple of times, I thought the seasoning could be better, so I decided to start over.

I used soap and a sponge scourer to get most of the patina off. To get more off, vinegar seemed like a good idea, so I boiled vinegar and water in the wok for about five minutes, let it cool, and scraped most of the remaining patina off. The wok looked (almost) good as new, so I dried it and proceeded to re-season it.

I applied my original seasoning procedure, which went well, but then the trouble started. I rinsed out the wok with hot water and rubbed it with a kitchen towel. In the center (where the metal gets the hottest, presumably), some of the patina stuck to the towel, and left iron-colored spots. I tried again twice, but the problem remained.

I thought maybe cooking in the wok would build up some patina, so I stir-fried some vegetables. Then, I rinsed and wiped it, and unfortunately, black flakes came off again. I can't seem to keep the entire bottom covered in patina.

So, any thoughts? Did I ruin my wok? Did the vinegar maybe form an oil-resistant layer or something? Anything I can try, or should I just get a new wok? Thanks.

Answer 1

You have overcooked the seasoning. I have done this once or twice too. Especially smooth surfaces (e.g. carbon steel) are very prone to this problem, unlike rough cast iron.

What you want is not a dark layer. The layer will darken with time and start looking like usual. But on a freshly seasoned metal utensil, the layer should be yellow-brownish. The stove may be too hot for this, especially a gas stove, I do my pans in the oven, for maybe an hour at 200 Celsius or somewhat lower. A burner under thin metal can cause hot spots of much higher local temperature, where the oil chars instead of polymerising.

There is also the type of oil you use. Generally, unsaturated oils polymerise easiest, but the final layer stays somewhat sticky. Saturated fat can give you some more trouble, but will have a smoother finish. I do multiple layers, starting with 1-2 layers of flaxseed oil - this gives a good basis, it is so unsaturated it can practically dry out by itself in the air - and finishing with cocos fat or lard, again 1 or 2 layers. For the first few time in a new pan, I try to fry with saturated fat too, for your wok you will probably find that the taste of cocos fat has a good harmony with Asian dishes.

And a word to the cleaning before: Vinegar was not such a good idea. Woks are made from reactive metals (that's why they need seasoning) and metals react with acid. Using acid to clean naked reactive metal will result in invisibly small pockets of reaction products on the surface of the wok, mostly rust. You can do this as an early step in cleaning, but afterwards you have to use something to make sure you have removed this too. To peel off the seasoning before reseasoning, you are much better off using a base, as it does not react with the metal. This will ensure that the new seasoning sticks to the metal itself and not to impurities which can be dislodged over time.

Answer 2

Mine was having the same problem; I suspect I didn't get the factory coating off well enough.

I ended up having to go through a lot of work to strip the seasoning. I tried alternating between steel wool, and a plastic scrub pad, soap, barkeeper's friend, boiling water in it with baking soda in the water, and even wiped it down with acetone. After that I took one of those little $2 drill attachments that are buffing wheels on a drill bit and buffed more barkeepers friend on it at full blast. This finally got everything off.

Then I washed it with soap one more time and took the rack out of the barbecue and quickly put it in there after washing on full heat and shut the door. It got up to about 650 degrees pretty quick (I have a little point and shoot IR thermometer). The hot areas began to turn bright blue and rainbow. The areas I suspected still had factory grease on them appeared to have as a few little black scorch marks in the shape of drips formed in those areas, then burned off and wiped away. I moved the wok around until the whole thing was burned off and blue/rainbow.

I let it cool slightly so the oil wouldn't catch fire (probably to 450 degrees). And took a napkin with refined coconut oil on it the edge (not a lot) and quickly wiped it over the surface so it wouldn't pool. It smoked like crazy as opposed to doing it in the stove. It instantly formed a great seasoning over the whole thing.

I massaged it as I cooked it for a bit, then I left it in at a lower heat so it stayed around 500 degrees for 15 minutes. I took it out and wiped it down with oil, then with a dry paper towel to see how much dark came off (not much - finally it was going right!) and then with a cloth towel to get all the oil back off.

I then put it on the stove top, took a large thumb of ginger, cut the edge off, and dipped the flat cut edge into some oil. When the pan was about 450 degrees on the stove top, I took the ginger and just kept rubbing it into the surface of the pan (I used BBQ mitts so I didn't burn myself) and re oiling it occasionally. I found this was way easier than the green onions method because I only had one thing in there and I could scrub the whole pan with it as it blackened. I was just holding the ginger thumb in my hand and literally pressing and wiping it all over the pan quickly so it left a residue but not char.

This made a fantastic slightly darker seasoning on the inside. (I'm kind of wishing I did it all over now.) Then for good measure I cleaned it off again and stir fried some green onions in oil.

Now my wok is working beautifully; it looks awesome too, all sorts of colors none of which look dirty or rusty. A napkin wipes clean after use, usually on the first oiling but sometimes on the second. There's a dark patina building up that seems nice and set. What a pain but now it's pretty sweet, and I can stir fry at very hot temps with rice grain oil without it smoking so the stir fry tastes just awesome. I might coat the outside in flax oil and bake it for a bit just so the whole thing looks nice and even, but I don't really like flax oil inside for woks like I do for cast iron. It doesn't seem to stick well to the smooth steel and burns off too much (will get black dust that is hard to oil off and needs to be oiled off if you want your next seasoning to stick to it) if you wok above 400 degrees like I do.

Answer 3

I have seasoned my carbon steel wok perfectly, fried eggs just slide on it's surface. Here is a tip when you finish the cooking do not wash the wok with any detergent just plain hot water, don't scrub be fairly gentle. Just put the rinsed wok back on the heat to dry it, don't wipe it dry. When you use your wok again, heat it 1st, then add oil as per the recipe, never add oil to a cold wok. If you use your wok for steaming or boiling always heat & coat with Oil to protect it after use. Good luck

Answer 4

From: Cooking Lessons From The Kitchn - How To Buy and Season a New Wok

How to Season a Carbon Steel Wok

What You Need...

Ingredients:

1 bunch scallions, chopped into 2-inch pieces 1/2 cup sliced unpeeled ginger 2 tablespoons grapeseed, canola, or peanut oil

Equipment:

1 unseasoned 14-inch carbon-steel wok Stainless steel scrubber Liquid dish soap Spatula

Instructions:

1. Wash the New Wok: Unseasoned woks are coated with a factory oil to protect the metal and keep it from rusting until it is sold. This needs to be scrubbed away before the wok can be seasoned. Thoroughly scrub the wok inside and out using a steel scrubbing pad and dish soap. Rinse with hot water.

2. Dry the Wok: Set the clean wok over low heat and let it dry for 1 to 2 minutes, until no water droplets are visible. (We’ll cover wok cleaning in a separate post, but know that this is always the right way to dry a wok; it should be dried over low heat until no water remains. Otherwise, it can and will rust.)

3. Prepare Your Wok Space: Open the windows and turn on the exhaust fan. Although the wok is clean, some chemicals from the oil will still remain; make sure your kitchen is thoroughly ventilated before seasoning. Set the bowls with scallions, ginger, and oil near the stove. Also, have a very small bowl of water next to the stove.

4. Heat the Wok Turn on a stove burner, as high as it will go. Set a 14-inch wok over this high heat burner. To determine when the wok is hot enough, start flicking droplets of water from the small bowl into the pan after 30 seconds. As soon as a bead of water evaporates within 1 to 2 seconds of contact, the wok is heated and ready for stir-frying. (In some new woks, the water may not evaporate immediately. It may just roll around like a mercury ball. This is common with new woks. After heating the wok for about a minute, add the oil.)

5. Pull Wok off the Heat and Add Oil: Pull the wok off the heat and add 2 tablespoons of oil. Pick up the pan and carefully swirl it to coat the bottom and sides. (If the wok smokes wildly the moment you add the oil you’ve overheated the wok. Remove the wok from the heat and let it cool for a few minutes. When it’s cool enough to handle carefully remove the oil with paper towels, wash the wok, and start again.)

6. Add the Aromatics to the Wok: Put the wok back on the heat. Add the scallions and ginger.

7. Reduce Heat and Stir-Fry: Reduce the heat to medium and stir-fry the aromatics for 15 to 20 minutes. Smear the aromatics up the sides of the wok all the way to the edge. If the mixture becomes too dry, add an additional tablespoon of oil as needed.

8. Watch for Color Change The color of the wok will gradually change from shiny new silver to mottled light yellow-brown. You may possibly see some blue, bright yellow, or even black colors; this is fine. (With some woks there will be no change. Every pan will react differently.) The wok will also start to look smoother.

9. Cool and Wash the Wok Remove the wok from heat and let it cool. Discard the aromatics. Wash the wok with hot water (no dish soap).

10. Dry the Wok: Set the wok over low heat and let it dry for 1 to 2 minutes, until no water droplets are visible. The wok is now seasoned and is ready to be used for cooking.

Wok Care After Seasoning:

New Woks are Hungry for Fat... meaning that it will soak up any fat you give it. This also helps develop the seasoning on the new wok. Cook anything that uses fat: stir-fries, deep-fat frying, cooking bacon, etc.

Things to Avoid:

Avoid steaming, boiling, or poaching in your new work. Also avoid cooking with an acid such as tomatoes, vinegar, and lemons. These things are fine once you’ve been using your wok for a while, but can damage the delicate seasoning on the newly-seasoned wok.

The Teenage Wok:

Woks go through an adolescent stage before they develop the deep patina and nonstick coating of a well-used wok. During this stage (and throughout the life of a wok), the seasoning can look splotchy, feel gummy, or develop rust spots (especially if you live somewhere humid or go a few weeks between uses). This is all fine. Just keep cooking and the patina will develop.

How To Give Your Teenage Wok a Facial:

To give a wok a facial and clean up any yellowed, gummy, or rusted spots (this happens especially often with a new teenage wok):

Fold three layers of paper towels into a pad. Heat the wok as described above. Off the heat, swirl in 1 1/2 teaspoons oil and 1 tablespoon kosher salt. Scrub all over with the pad of paper towels until the gumminess and rust spots are gone. Repeat as needed. Throughout your wok’s life, you can rejuvenate it with this wok facial.