The Food Lab: The Best Wonton Soup
It's time for another round of The Food Lab. Got a suggestion for an upcoming topic? Email Kenji here, and he'll do his best to answer your queries in a future post. Become a fan of The Food Lab on Facebook or follow it on Twitter for play-by-plays on future kitchen tests and recipe experiments.
My love for wonton soup may not be as deep as my sister's, who dives into a bowl with a passion only rivaled by her love of beef chow fun, but it still ranks up there in the "top five soups" category for me.
I'll admit it: the wonton soups of my youth—the one that originally made me fall in love with the salty, slippery, comforting dish—were probably not good. Ordered from takeout joints or strip malls on the way home from ski trips, they had thick, clumsily made wontons and a broth that tasted mostly of salt with a hint of cabbage.
Since then, I've made it a mission to try all of the wonton soup in the city worth trying (a pretty tall task) and have discovered that when done right, wonton soup need not be the cheap appetizer of choice, but a worthy dish unto itself. There're the Chinese-American roast pork broth version with thick skins sold at barbecue shops, or the large, pork and bok choy-filled versions served floating in chicken soup with noodles at the Shanghainese restaurants. At the city's handful of Fu Zhou restaurants you can get broth filled with dozens of wispy, comet-shaped wontons and bits of pickle and dried shrimp.
But my favorite version—the version that's good enough to eat like a meal and not just an MSG headache-inducing appetizer,* is the rich, shrimp and pork version served in Hong Kong. The broth, a far cry from the salty, one-dimensional versions I had as a kid, is made with pork (and sometimes chicken), with a rich body and a faint aroma of the sea imparted by dried flounder and shrimp. The wontons are stuffed fuller than most, folded into little round parcels, filled with juicy pork and shrimp that pop out as you bite through the thin, thin skins; the shrimp crunching under your teeth as you chew.
*yes I know, MSG headaches are a myth or at best psychosomatic. Unless you eat MSG-laden wonton soup on an empty stomach, perhaps.
This is the version of wonton soup that I crave, and this is the version I was after in my own kitchen.
Part 1: The Broth Base
Just like great French or Japanese food, good broth is one of the backbones of Chinese cuisine, and the most important broth when it comes to fancy soups is superior stock, a rich broth made with pork, chicken, Jinhua ham, and aromatics.
The chicken part of the broth is easy—chicken backs are cheap and packed with bits of meat and fat that give the broth flavor, along with plenty of connective tissue that breaks down into gelatin over the course of a long simmer, lending body to the broth.*
*I've been informed that many restaurant in Hong Kong in fact do not start with a superior stock, instead using just pork and seafood. I'll stick with chicken in mine, as they're cheap and a great source of gelatin and flavor.
But what about the pork?
I tried making broths using pork neck bones and pork trotters—two of the most commonly recommended cuts.
The difference between the two is pretty striking. Trotters, just like hands and feet, are packed with tons of short bones, and many bones means plenty of connective tissue to enrich your broth. A broth made with just neck bones doesn't get much richer than one made with chicken alone, though it does acquire a sweet, porky flavor. Check out how thick it is when chilled:
You can see there's a small amount of gelatin in there, but not much.
Now take a look at how thick a pork trotter broth gets:
Gelled enough to hold its shape and be scooped! Texture-wise, this translates to a richer, more mouth-coating, lip-smacking feel. Flavorwise, however, pork trotters don't pack as much punch as pig necks. Normally, I'd recommend using a mixture of both, but in this case, since we're still going to be adding so many aromatics and yet another form of pork to the mix, the added flavor benefits of using a combination of neck and trotter gets lost in the long run.
Pork trotters and chicken it is.
Next up: The ham.
Jinhua ham is a Chinese salted ham from Jinhua provice that's been produced since at least the 10th century AD (take that, prosciutto and serrano!). It's a basic salted, aged ham that is quite similar to American-style country hams, which is good news if you don't live nearby a Chinese market that sells it. Unlike its European and American cousins, Jinhua ham is used primarily for flavoring soups and stews, not for eating plain.
For my next batch of broth, I tried adding a hunk of it along with my bones and simmered the whole thing for a few hours. the broth came out ridiculously salty as the ham slowly leached its salt into the water. Lesson learned: just like with an American-style country ham, you must blanch your ham before you cook it.
I also tried using a few different substitutions for the Chinese ham and found that a chunk of country ham (or a country ham bone) or a chunk of prosciutto (you can generally get prosciutto ends relatively cheap from Italian delis) are the best substitutes, though even a hunk of bacon or salt pork will do the job.
For Clarity's Sake
One thing I immediately noticed with my finished broths was that they were slightly brown and very cloudy. This is due to the clotted blood, proteins, and other impurities that are leeched out of cut bones during the first few minutes of the simmering process:
As with Japanese-style tonkotsu broth, blanching the bones briefly in boiling water, then dumping the water, scrubbing the bones, and starting with fresh water will give you a clearer broth with a cleaner flavor.
You wanna see what you're trying to get rid of?
This. Not pretty, right?
I dump my pot, bones and all, directly in the sink then rub the bones all over under cold running water, using my fingertips or a chopstick to get out all of the bits of gunk that are caught in their crevices. It's actually strangely satisfying, the way a dermatillomaniac loose in a room full of tethered acne sufferers might be satisfied.
When you add the fresh water and bring it up to a simmer again, the only stuff that floats to the surface is fat and a small amount of clean, white flotsam.
Some folks like to meticulously skim away this fat and scum, but I've found that so long as you get rid of the gunky black stuff that coagulates within the first fifteen minutes or so, you actually end up with better flavor if you don't skim your broth until after straining it.
The great thing here is that since we were planning on blanching our salty ham anyway, you can just throw it right in the pot with the rest of the ingredients. Most of the salt will leech out during the initial boil.
skimming stock after cooling lets you scoop it off with a spoon. (Of course, if you want to eat the soup on the same day, you can skim with a ladle after cooking).
This one is easy. The major aromatic elements in a superior stock number only three: ginger and scallions start the party.
And Napa cabbage raises the roof.
Let's not mess with what ain't broken.
Now here we've got a number of questions. First off, what does seafood even bring us?
Well some ocean-y aroma, obviously, but there's another important factor: flavor enhancement.
We all know that the salt of glutamic acid (A.K.A. monosodium glutamate or MSG) is the natural compound largely responsible for the sensation of umami in foods. It's what makes things like hams, parmesan cheese, or soy sauce taste so savory.
But there are other compounds that can enhance the effect of glutamic acid, namely inosinate and guanosine, two proteins that are found in abundance in seafood, particularly dried seafood, where it gets concentrated. On their own, inosinate and guanosine have no real flavor, they merely act to increase our own perception of savoriness, much like sprinkling your meat with salt will not just make it taste salty, but will actually make it taste more like itself.
There's a reason why disodium guanylate—a salt form of guanosine—is used regularly as a flavor enhancer in instant noodles and chips.
You can get it in powdered form (if you look hard enough and buy in bulk), but fortunately for us, there are natural sources.
Dried seafood is the most abundant source, and I tried making broths with dried shrimp, dried fish, and dried scallops (our office happens to be situated above a dried seafood store). Of the three, the scallops were best, with an intense savoriness and a very mild seafood aroma that didn't overwhelm the dish with fishiness.
That said, it's not easy for everyone to find dried scallops.
"Since we're going to be putting shrimp into our wontons anyway, might as well get the most out of'em, right?" I thought to myself.
I bought a couple dozen head-on, shell-on shrimp, peeled them, then used the heads and shells to flavor my broth. It had some of the seafood aroma I was looking for, but lacked the deep savoriness you get out of dried seafood.
The solution? Use a combination of fresh shrimp shells, along with a strip of Japanese kombu—dried giant sea kelp rich in gluatamic acid that pushes the savory factor of the dish right up to where it belongs.
Bingo. Flavorful broth with a mild seafood aroma and a deep savoriness, without having to resort to expensive dried fish.
We're on the home stretch here.
The filling for Hong Kong-style wontons is generally made with lightly seasoned pork flavored with ginger, yellow chives,* soy sauce, and sesame oil, along with some form of shrimp. In the simplest version, the shrimp is ground up right along with the pork, but I personally prefer the version in which the shrimp are left intact, each wonton being stuffed with a single plump, crunchy shrimp.
*a variety of young chive that has a more delicate flavor than either regular chives or scallions, the either can be substituted in a pinch
I've made enough dumplings and wontons in my day to know how to make a good basic pork filling (use plenty of fat, season it properly and taste it by microwaving a small portion on a plate for 10 seconds), so I figured making these shrimp and pork wontons would be as easy as sticking a shrimp into the wrapper before sealing and boiling it.
The wonton that came out had perfectly cooked pork accompanied by a rubbery, mealy shrimp.
How the heck do those restaurants get their shrimp so crunchy?
Serendipitously, just last week a reader emailed me a link to an article on Rasa Malaysia that addresses this very issue. The answer? Alkaline water. Apparently, soaking shrimp in a bath of water with baking soda for fifteen minutes to up to a day will alter their texture, delivering that crunch I was looking for.
I tested this by trying shrimp soaked in plain water (my tap comes out slightly alkaline at a pH of 7.5), shrimp soaked in salt water, shrimp soaked in baking soda-spiked water, and completely unsoaked shrimp.
The salt water shrimp came out a little bit juicier—bring can help meat retain moisture—while the baking soda water showed a clear improvement in texture; The shrimp nearly popped in my mouth. Combining baking soda and salt was the best option, delivering shrimp that were both crunchy and juicy.
To be honest, I'm not exactly sure why the technique works, but I'm looking into it and will get back to anyone who has questions.
With a great broth and a killer filling with crunchy shrimp, the only thing left to do is form the wontons.
I use store-bought skins (the square kind, not the round dumpling variety) of the thinnest gauge I can find. If you have an option between plain wheat flour wrappers and those that are enhanced with egg yolk, go with the latter, as they stand up to boiling a little bit better, developing a nice chewiness as they cook.*
*be aware that some brands of wonton wrappers offer both white and yellow varieties, the only difference being the inclusion of food coloring to simulate eggs.
You can shape your wontons any way you wish. The easiest is the comet-shaped wontons where you place a wrapper on your hand, add a small dollop of filling and a shrimp, then squeeze it all shut. Almost equally simple is a triangle shape, in which you lay the wrapper flat on a board, add the filling, then fold the wrapper over. In either case, make sure to moisten the wrapper with a fingertip or brush of water before sealing to help it close up tight, and squeeze out as much air as possible before sealing in order to prevent them from blowing out as they simmer.
If you want to be extra fancy, you can form little tortellini-like purses, which allows you to maximize the amount of plump filling within each wonton. The process is slightly more complicated, but not hard once you've got the hang of it. Check out the step-by-step slideshow here for instructions.
Now doesn't that look like something you'd like to slip into your gullet? I know I do.
The best part about making wonton soup at home for me is this: the store-bought version never has enough vegetables. Those tender bites of cabbage and slivers of yellow chives are some of my favorite parts.
Making it at home lets you load it up right.
And while we're at it, we may as well throw in a handful of noodles as well. My mother always said there's no use in letting a good broth go to waste.*
*At least, I wish I had the kind of mother who dispensed pearls of ancient Chinese wisdom like this a bit more regularly.
Both the broth and the wontons can be made ahead and frozen. To freeze the wontons, place them on a parchment-line plate, cover them loosely with plastic wrap, then place them in the freezer until completely frozen, about 1 hour. Transfer them to a plastic bag. They can be cooked directly from frozen, just add 1 to 2 minutes to the cooking time.
Get The Recipe!
About the author: J. Kenji Lopez-Alt is the Chief Creative Officer of Serious Eats where he likes to explore the science of home cooking in his weekly column The Food Lab. You can follow him at @thefoodlab on Twitter, or at The Food Lab on Facebook.