Thursday, April 5, 2012

Seasons of Wok


[UPDATE]
See my new post, in which I discuss the resolution of the seasoning's "flaking" mystery, and other revisions to my wok/cast iron seasoning approach.
[/UPDATE]


I think I finally have a good understanding of how to season a wok. You really just have to properly cook with and clean it, and the seasoning will build naturally--the short cuts don't work. At least, the practices that I had read and been following didn't work. Here's what I've found in my experience:

If you search the internet for information on seasoning a wok--or even look at the instructions that came with my Joyce Chen wok, which were essentially the same--they'll generally give you one of two strategies, or both:
  • Lightly swab your wok with vegetable oil, peanut oil, or lard, and roast it in the oven facing downward so the oil doesn't pool at the bottom. Allow to cool completely and repeat this several times.
  • Lightly swab your wok with vegetable oil, peanut oil, or lard, and heat it on your (gas) stovetop over high heat until smoking (turn on your fan and open a window), tilting the wok so that the sides are heated and carbonized, too. Allow to cool completely and repeat this several times.
This doesn't work. Or at least, the stovetop strategy didn't work for me. Over a long period of time, too. I couldn't try the oven strategy since my wok has plastic components that don't detach.

The problem is that with the stovetop strategy, the oil burns onto the wok surface in a thin, hard layer, but doesn't seem to bond to the carbon steel correctly. You actually get a dark, black coating very quickly with the stovetop strategy--in the first round, even; the black coating on the higher areas of my wok are from just one round of stovetop seasoning with canola oil (more on canola oil later). Because the carbon layer isn't bonded correctly, it eventually starts to crack and flake away as you cook with it. This took a very long time to happen to me the first time, I'm not sure why. After the seasoning started to flake the first time, subsequent attempts to season my wok the same way only resulted in cracking and flaking much sooner.

So what should you do? Unfortunately, there is no shortcut to building up your wok's seasoning; you just have to cook with it. I think the carbonization of the oil has to build up very gradually, and very thinly in order to season the wok correctly. If the carbonization builds too quickly and thickly, you end up building a false carbon shell rather than true seasoning.

But, there are practices you should follow so that the carbon seasoning can properly build up. Here's what has worked for me:

Cooking with your wok:
  • Use a bamboo spatula. Chinese-style bamboo spatulas have an angled, rounded edge, which is great for your rounded wok. The bamboo also won't scratch the seasoning that you're trying to build up. Here's an example of one. If you have a Chinese supermarket near you, you can definitely pick one up for cheap, there. Grace Young always says to use a metal wok spatula in her Wisdom of the Chinese Kitchen book, but I find that this scrapes up the seasoning a fair amount. Certainly, the metal wok spatula, which is sort-of shovel-shaped, is convenient as a stir-frying tool, but not helpful if you're trying to build up seasoning.
  • Don't use canola oil. This is mentioned on various websites, citing "gunkiness" that results from using canola oil. I've found the gunkiness problem to be true, too, though I also worry about the thickness with which canola oil carbonizes, probably related to its gunkiness. Canola oil burns on to your wok very thickly, which means that even after one round of stovetop burning, the carbon layer looks very black. I wonder, though, if this makes it easier to quickly build up the false carbon shell that gets in the way of true seasoning. I also wonder if the thickness of canola oil carbonization negatively affects the high heat transfer that you want for stir-frying and browning without sticking.
    • I've found peanut oil to work well for me, though you still can't use the stovetop strategy to season your wok. As mentioned above, stovetop strategy leads to false carbon shell.
    • You want an oil with a high smoke point, since the whole point of cooking with a wok is to use high heat to sear your stir-fries.
  • Acidic foods like vinegar and tomatoes will tend to inhibit or eat away seasoning. However, as long as you're not soaking the wok in acidic substances for long periods of time, I don't think it's really a problem.
Cleaning your wok:
  • Rinse your wok with hot water. After cooking with the wok, turn your faucet to full blast on its hottest setting. Then use the jet of water to rinse out the wok. Afterward, if there are still little bits of burnt food left, clean them out with a bamboo cleaning whisk, and rinse again.
  • Get a bamboo wok cleaning whisk. This made a big difference for me. The bamboo is stiff enough to knock away burnt bits on your wok without damaging the seasoning as it builds up. The bamboo is actually too firm to use as you might a whisk for beating eggs. Rather, use the whisk and bristles in a sort of "pushing" motion to clean burnt bits off the wok, and not a "swishing" motion. Here's the one I'm using, which is a good size for a 14" wok.
  • Dry your wok over the stove. Put your wok over a medium flame to speed up the evaporation and ensure complete drying to avoid rust.
  • You DON'T need to stovetop-season your wok after cooking. As discussed above, this only leads to false carbon shell formation.
  • You DON'T need to swab your wok in oil after cooking. Guides will often say to rub your wok down with a thin coat of oil before storing to avoid rust. This is vague, though I think when people say this, they mean before putting your wok away for a long time. But why would you put it away for a long time? So, alright, if you don't anticipate using your wok for a long time and you don't have a good seasoning built up, then a coat of oil probably helps. However, if you use your wok occasionally even, as I do (anywhere from a couple times a week to once in two weeks), you don't need to coat it in oil.
What to look for:
  • A deep brown, matte surface. Properly seasoned, the wok surface will have a matte (not glossy) finish and be deep brown--not glossy and black. If it's glossy and black, that's a sign you've got a carbon shell forming.

In the photo above, you can see both black and brown parts. The black areas are where I had previously built up carbon shell. The deep brown is where the carbon shell has gradually fallen away as I cooked and cleaned my wok, revealing or making room for (?) the deep brown, true seasoning. Honestly, I'm not sure about the transformation going on here. When I've done the seasoning incorrectly before, the carbon shell has fallen away to reveal shiny, silver metal. As I'm just going through, cooking, cleaning, and cooling without after-cooking-stovetop-seasoning, my wok is slowly transforming without the cracking and flaking.


Here, you can see an example of glossy black carbonization. The higher areas of my wok still have the false carbon shell remaining from when I stovetop-seasoned it with canola oil. Were these areas exposed to more intense heat, as the bottom of the wok is, they would eventually crack and flake away. Still, it is a quick and convenient way to make your wok look prettier, rather than having just the bottom dark.

What to do if your wok is cracking and flaking. Unfortunately, if this is happening, you can't just stovetop-season over the flaking parts. The cracking and flaking will continue and spread. You just have to scrape away the flaking parts of the wok (generally the bottom area, which is in contact with higher heat) and start over.

In summary, if you are patient and work properly with your wok, the seasoning will gradually build up on its own. I hope my notes have been helpful, and happy cooking!

5 comments:

  1. grape seed oil is a great alternative of oil too. Great informative article, Wil!

    ReplyDelete
  2. Great article! Been having same problems with my wok. Will try as advised! Thanks

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  3. Great article! Been having same problems with my wok. Will try as advised! Thanks

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  4. This may be a stupid question but here we go. I just made a large stir fry in a friend's wok. There are a ton of flakes IN ALL of the food? Do I have to throw it away?? Will it be harmful to eat?

    ReplyDelete