Thoughts on Woks

 A conversation came up the other day about stir-fry, and woks in particular, and there seemed to be some confusion (and maybe a bit of fear) about the two.  Thankfully, it's not that hard, there are just a lot of options and the trick is mostly figuring out what's going to be best for you.

First things first, though, it's worth talking for a minute about stir-fry theory.  The underyling secret to a good stir-fry is heat – to a large extent the more the better.  The high heat sears the outside of the meat & veggies and traps the flavors in before they cook all the way through.  So the trick is getting as much heat to the cooking surface as possible.  After that it's controlling that heat, and technique.

So let's start by wandering over to William Sonoma's wok page and looking at their wares.  There are a lot of fancy things, but the two I would buy are both under $35 and I think you'll see why in a minute.  There are certain generic things to look for in any wok:

• NO NON-STICK.  Teflon-try coatings are the worst.  They can't handle the heat required to do a good stir-fry, and once Teflon is compormised it's really bad for you, and you should toss the cookware.  More importantly, non-stick means that the surface is also sealed against oils and the like from seeping into the metal.  Basically, it's impossible to properly season a non-stick wok, and a properly cared-for wok will be non-stick anyway.
• NO ELECTRIC. I've never seen one that can get hot enough, for one thing.  They also tend to be non-stick (see above).  Third, they're stationary objects so you can't move them around, which impedes handling the food properly.  There are other options that will work with nearly any stove surface.
• LOW THERMAL MASS.  More metal means more time to heat up, and makes it dificult to fine-tune temperatures.  Period. Heavy metal \m/ proponents talk about stability and durability, but that also means you can't move the wok around easily either.  Watch someone who knows what they're doing use a wok – they spin it, flip it, and generally have it in constant motion throughout the stir-fry part.  Obviously not so much when they're simmering or the like.  
• TAPER.  A good wok will have a thick bottom, and taper down to a thin ridge, and there's a good reason for this.  The bottom of the wok absorbs the heat, but it's equally important to transfer that heat as equally as possible up the sides, so the heat is even throughout the wok surface.  Taper means less metal, which means better (and faster) heat transfer up the sides.
• SIZE. You'll want something appropriate to your household.  I've got a 16" wok since there are often five of us (including three teenagers).  That's a lot more wok necessary for two people, and while overall not a terrible thing, it means more energy to heat up the cooking surface than you need.  It also takes up more storage.

Those are kind of the basics, and I think it's apparent given my notes above that you can easily spend a lot of money on a product not really suited to the purpose, but looks pretty.

So, I'll introduce you to my wok and we can move from there.

My baby is a 16" round-bottom cast-iron dealie.  I know that sounds odd, but it's a 'traditional' (old-school) Chinese wok that I picked up in SF's Chinatown for about $35 includng a lid, spatula, fire ring, and bamboo brush. I think the wok itself would have been under $20.  There are a couple of reasons I chose this one, but I'll come back to that later.

Before I do that, it's probably a good time to talk about various materials and woks, and some of the pros and cons.

Materials:

• Cast-iron woks are the oldest, and probably what you would find in the kitchen of most families in China. They're kind of like a classic sportscar – light, fast, and easy to maneuver.  They season almost immediately and care is the same as carbon steel.  Unfortunately, like a classic car they can be brittle, and prone to cracking if you're the sort of person that drops things a lot.
• Hammered carbon steel is the most popular wok material, whether hand, or machine hammered.   My limited metallurgical understanding suggests that the hammering process aligns the steel molecules in such a way that it creates a structure that has a nice homogenous alloy resulting in an even cooking surface.
• Stamped steel is the sort of thing people sell to tourists.  I wouldn't go there.

Shapes and cooking surfaces:

• Round-bottom woks are what you want to get if you have a gas range.  The shape of the bottom directs the flame up the sides of the wok for a hotter surface throughout.  Round-bottom woks can be both cast iron, or hammered steel.
• Hand-hammered flat-bottom woks are excellent for most electric ranges.   The flat bottom sits directly on the burner, maximizing heat transfer.  I don't honestly know why hand-hammered is better than machine-hammered, but it's the choice for a lot of chefs.  
• Machine-hammered, or smooth-bottomed hand-hammered woks are pretty much the only choice for induction ranges.  A normal hand-hammered wok has an uneven bottom that isn't a big deal for standard electric ranges, but are hell if you're tring to get a hot wok on an induction range.

So why did I choose my wok?  The cast iron is lighter than most of it's steel counterparts.  It also seasons quicker and (IMO) spreads the heat faster than it's steel brothers.  There isn't any appreciable difference in care and feeding, and in my case there wasn't any real difference in price.  What's right for you?  Best bet is to take all this and go someplace you can pick up a number of them and see how they feel in your hand.  If you're in San Franciso, I particularly recommend The Wok Shop on Grant in Chinatown (they also sell on-line and this isn't a paid endorsement, the people running the place are just awesome).  If you don't live in SF wandering around your local Chinese area is also where I'd start.

Finally, a few notes on care and feeding for your new wok.  Whether carbon steel or cast iron, the basics are the same:

•  As soon as you get your wok home, wash it several times with hot water and soap.  A coating is applied to the surface to prevent rust, and you really don't want that in your food.  Next, coat the wok with oil both inside and out and bake it upside-down in the oven at 350-400F for 30-40 minutes.  Let cool, re-coat with oil, and repeate one or two more times.  This works the oil into the pores of the metal and provides your long-lasting rust protection, and also gets the surface ready for seasoning.
• Seasoning is fairly simple.  Get the wok really hot and add a little oil (note: You should always get the wok hot before you add the oil) and throw in some aeromatics – chives, green onions, that sort of thing – and stir-fry them until they're black.  Try and coat as much of the cooking surface as possible in the process.  Let cool, rinse with water and scrape off the bits with a  bamboo brush and you're literally ready to cook.  Note, carbon steel takes a little longer to really soak up the flavors, but it's more of one of those "gets even better with time" things, rather than a "gonna take a while to taste right" thing.
• Never use soap on your wok unless you can't possibly avoid it.  Immediately after each use, rinse with water, and knock off any food bits with a brush and re-coat with oil.  Trust me, people have been doing this for a thousand years so it's pretty safe.  If you have to use soap for some reason, go back and re-coat/bake the wok and reseason.
• When cooking, always get the wok as hot as possible, then add oil, bring that up to temp and start cooking. This assures that your wok is as hot as possible before you start adding food.

On a side note, if you have a gas range, here's an Ancient Chinese Trick (well, I learned it from the guy thay owns The Wok Shop anyway) – take the flame ring and attack it with a pair of tin snips (shears designed for cutting thin metal) so that the ring sits down over the burner grate.  This gets the wok not only closer to the flame, but also keeps the ring from sliding around when you're trying to cook.  Mine, a 2.5qt sauce pan sits nicely inside the ring, so I just leave it there: 

Any questions or comments?  Feel free to drop me a note in the comment box below.