Sichuan’s Naturally Fermented Pickles (Pao Cai)
A Lacto-Fermented Pantry~~
Have you ever tried making pickles without vinegar? There’s a bit of a learning curve involved in letting natural lacto-fermentation sour your vegetables instead of vinegar. But there’s also huge payoff for the effort. Not only in health benefits—fermentation creates good bacteria, or probiotics, that aid in digestion and vitamin absorption—but in culinary benefits as well, since the vegetables taste like sour versions of themselves instead of like vinegar.
Now I love a good vinegar quick pickle, but naturally fermented vegetables are useful not just as condiments and appetizers but as cooking ingredients. Sichuan food makes frequent use of fermented vegetables—particularly red chilies, long (or green) beans and cabbage—from the home pickling jar to whip up quick stir-fries to top rice or noodles. So once you’ve mastered the art of brine pickling, you always have highly flavorful vegetables ready to go for both snacking and cooking.
I’ve been working on Sichuan-style naturally fermented pickles, or pao cai, on and off for a few years now. Seriously, years. Sometimes I get it right, and sometimes I get it wrong, but really I just made it harder than it has to be to naturally pickle a vegetable. I have consulted many sources over the years, and they all seem to take different approaches—which just proves that pickling is both a science and an art. There are many ways to do it, not just one right way, and you’ll have to experiment and find your own best method and taste. But here I hope to shorten your learning curve.
In this post, I’ll share my own trial-and-error lessons in Sichuan pickling, and a soon-to-follow post will provide an all-purpose pork-and-pickle stir-fry recipe that goes with rice, noodles or lettuce cups.
While fermentation in all forms has become trendy in the U.S., fermenting is not a fad in Sichuan. Many home cooks still feed their giant pickling crocks on an ongoing basis—taking vegetables out, putting new ones in—the brine growing ever more intense and intriguing over time.
Recently, America’s own fermentation guru, Sandor Katz (who, like us, lives in Tennessee) did a fermentation tour of southwest China and captured it all on video. “The People’s Republic of Fermentation,” made by filmmaker Mattia Sacco Botto and also featuring Mara King, a “probiotic pickleteer” from Colorado, is seriously awesome, so I hope you’ll both watch it and vote for it as the Best Food Video in the 2017 Saveur Blog Awards. The first three episodes all take place in Sichuan, and episodes one and two, in particular, focus on pao cai (among other appetizing things), episode three on douban jiang, and the remaining episodes on the fermentation of various things in Guizhou and Yunnan.
I had three major stumbling blocks on my own pickling journey: finding just the right container and method for submerging the vegetables under the brine; getting just the right salt concentration; and fermenting just the right amount of time for my personal taste and recipe use. So let’s break these down.
In the two photos above, I’m using Sichuan pickling crocks, one in glass and one in earthenware. The Chinese crocks have a narrow opening with a moat around it. You fill the moat with water, and it serves to seal out oxygen while letting the carbon dioxide from the fermentation process escape. This makes for some unusual burbling sounds in your kitchen, which Carolyn Phillips calls farts. She even calls her pickle jar the fart jar, as she tells it in her majestic but plain-talking pan-China cookbook, “All Under Heaven.” (While you’re at the Saveur site, you should also vote for Phillips for the Food Obsessive Award in the 2017 Saveur Blog Awards.)
You can find the glass version of this crock at The Wok Shop or sometimes in Chinese supermarkets in the U.S. Harder to find are the earthenware ones, though I recently stumbled on this one at Great Wall Supermarket in Atlanta. You can also use a wide-mouth crock or glass canning jars, which I’ll discuss below.
My biggest problem with lacto-fermentation was that, unlike a vinegar brine, as it progresses, the salt brine starts to go cloudy. Sometimes it even forms white scum on the top. Whenever this happened, I would ditch the whole crock full, owing to my strong aversion to mold or anything resembling mold, except where cheese is concerned. The cloudy brine and white film creeped me out, and I thought I was doing something wrong.
But this summer in Sichuan proved me wrong. The owners of Sichuan food brand Youjia took Fong Chong and me to eat at a high-end restaurant with Pao Cai in the name, where a hallway of glass pickle jars greeted us, several of them with a white film on the top. It was the same story at the Chengdu Shangri-La’s fabulous Cafe Z, where a wall of help-yourself pickle jars featured gorgeous pickles of all kinds floating in cloudy brine, some dotted with a white moldy substance.
Turns out that not only is that white growth normal, it’s not even mold. It is instead Kahm yeast, which is a natural byproduct of lacto-fermentation. It’s perfectly harmless according to the experts, and although it’s not tasty and you don’t want to eat it, all you have to do is just skim it off the top and go on to the crunchy and sour goodness below the brine.
It’s still more appealing to avoid it altogether, however, and several things can help with that. The main goal is to keep oxygen away from the vegetables. They naturally want to float up to the top of the container and poke their heads out, so you have to make an effort to keep them submerged below the brine. The narrow opening of the Chinese crocks helps with this, but you still need to weigh the vegetables down somehow with something that floats. The Sichuan pickle makers in the Katz video use parts of plastic water bottles. I’ve been known to use the flexible lid of a thin plastic container (ironically, the lid from a Whole Foods pickle bar container).
Big cabbage leaves also work pretty well to cover and hold down the other vegetables. If the leaf gets funky during the process, just throw it out and insert a new one. Even better is a combination of cabbage leaves and plastic. Whatever weight you use, the brine must always cover all the vegetables, which means checking on it after the first day or two to top if off with more brine if need be.
As my pickling jars have gotten progressively bigger, I’ve found it a bit harder to control the formation of Kahm yeast. So I suggest that people new to fermentation try a quart or liter canning jar, like a Mason or Weck jar. I particularly like the Weck jars because you can leave the rubber seal off and seal them only with the clips, which leaves a tiny space for the gases to escape. Fill it nearly to the top with the brine, leaving little room for oxygen, but leave the jar sitting on a plate in case it overflows as it ferments.
Another thing that helps deter Kahm yeast, as well as true mold, is the salt brine. But what’s the magical salt concentration that allows only good bacteria to grow but doesn’t make the pickles too salty to eat? In Fuchsia Dunlop’s “Land of Plenty,” she notes that the typical Sichuan brine is “very salty” and gives proportions of 2 ounces salt to 18 ounces water. This, to me, is inedibly salty, even for vegetables you’re going to cook, which can be saltier. Carolyn Phillips uses 1.25 ounces for every 18 ounces, or 5 ounces sea salt for 9 cups water, and I find even that too salty, though for longterm fermentation it may be necessary.
For my purposes, I have settled on 32 grams of salt for 24 ounces, or 3 cups, water, which is the right amount of brine for pickling in a liter or quart jar. I give the measurement in grams because it is important to measure the salt based on weight, not volume. That has tripped me up several times! For example, 4 level tablespoons of Diamond Crystal kosher salt weighs 32 grams, because 1 tablespoon of it weighs about 8 grams. But 1 tablespoon Morton kosher or sea salt could weigh anywhere from 14 grams to 17 grams—meaning you’d need only about half the volume of salt for the same weight.
You will not use all 3 cups of brine to fill the jar originally, but you will probably need the remaining 1/2 cup to top off the jar over the next few days.
I can get away with using this more palatable amount of salt because I prefer my lacto-fermented pickles on the young side. Like most people in Sichuan, I leave cabbage pieces in this brine for only about one day, producing the lightly sour pao cai that is eaten as a side dish with most meals, perhaps topped with some homemade chili oil. (Read all about the pervasive presence of this quick pao cai in Chengdu here.)
Sandor Katz recommends checking in on your fermenting pickles every three days to determine which length of time suits your taste. For long beans or green beans, which are not very large or dense, anywhere from 3 to 5 days is sour enough for my liking, at which point I’ll either cook with them or move them to the refrigerator, which greatly slows the fermentation process. The time of year also makes a difference, with vegetables fermenting noticeably faster in the summer than winter.
As a contrast, Carolyn Phillips lets her pickle crock go for two to four weeks before eating any. Like many Sichuanese, she keeps her brine and adds more brine and flavorings over time, but some people also start from scratch each time. It really depends on how well the ferment well and how good the brine tastes to you.
As I said, pickling, like all cooking, is both a science and an art. Let this pao cai recipe be the beginning of your own experimentation and creation. By the time your pickles are ready I’ll have posted a stir-fry recipe using pickled green beans, pickled chilies and pickled Sichuan peppercorns that you can use as a topper for rice or noodles or in a lettuce cup for a zippy, zesty meal.
- 3 cups water
- 32 grams kosher or sea salt (4 level tablespoons Diamond Crystal kosher salt, or about 2 tablespoons Morton kosher salt or sea salt)
- 1 tablespoon brown or white sugar
- 2 tablespoons Chinese white liquor or Shaoxing wine (or gin or vodka)
- 12 ounces hard vegetables such as green beans (or long beans), white cabbage, white or red radish, carrot, celery, cauliflower, fresh chili peppers
- 1 tablespoon Sichuan peppercorns
- whole dried Sichuan chilies, rinsed and dried
- fresh, peeled ginger slices
- 1 large, outer cabbage leaf
- Bring water to a boil and remove from heat. Add salt and sugar and stir to dissolve. Let cool to room temperature, and add liquor.
- Sterilize container and lid by rinsing with boiling water.
- Wash vegetables and cut them into large bite-size pieces. Leave green beans whole. Dry them well and add to pickle jar, along with the Sichuan peppercorns, dried chilies and ginger.
- Add brine almost to the top, then cover vegetables with the cabbage leaf, tucking it into the jar and making sure all other ingredients are under it. Top off brine and seal jar loosely. (If using a Weck jar, use only the clips and not the rubber seal; if using a Mason jar, just screw lid on loosely, allowing an escape route for the gases.) Refrigerate any extra brine. If using a larger jar or crock, you may need to weigh down the cabbage leaf with a piece of flexible plastic, small plate or other improvised, sanitized device, to keep all vegetables under the brine.
- Sit the jar on a plate in case of overflow, and leave in a cool, dark place such as a pantry or cupboard to ferment. Sample the vegetables every day or two to check their sourness. If the cabbage leaf has been exposed to oxygen and appears funky, replace it with a new, fresh one. Top off brine if it is not above the vegetables. When they are pickled to your liking, store jar in the refrigerator. Cabbage can take as little as 1 day, while green beans and other vegetables take 3 to 5 days or longer, depending on the size of the vegetables, the room temperature and the desired sourness.
- If using a larger jar or pickle crock, monitor it for the white yeast film that can occur naturally on the surface in lacto-fermentation and remove any that occurs. As you use the pickles, replenish the crock with more brine, seasonings and vegetables.