How to Maintain a Natural Sichuan Ferment for Months or Years

This is part two of our ultimate guide to making pickles the Sichuan way. If you are new to making Sichuan paocai or to lacto-fermentation in general, please read part one, “Starting Your First Batch,” first. There you will find the recipe for making a Sichuan pickle brine. 

Have you had success naturally fermenting Sichuan pickles? If you’ve yet to make your first batch, please start with our thorough guide to making Sichuan paocai. It will walk you through choosing a container, the type of salt and salt concentration, and the best vegetables to get started. This post, on the other hand, is for those you have successfully fermented a batch or two and are now obsessed! It will walk you through maintaining a brine that is sour but fresh, intensely but appealingly fragrant and flavorful, so that you can have super healthy probiotic, low-calorie pickles on the counter in your lovely Sichuan pickle jar at all times and for years to come.

If you are new to natural fermentation, glass paocai jars are ideal. There’s something very satisfying about seeing the transformation in the vegetables as they go from fresh to pickled. Not only do the multicolored vegetables look vibrant and sexy in their glass jar for the first couple days, but you will be able to see if and when fermentation begins, as the brine begins to bubble and go cloudy and the vegetables begin to darken. You can also easily monitor for harmless kahm yeast and scary mold. A glass paocai jar is also recommended if you plan on short ferments, such as cabbage and radishes, or plan to keep the brine going for only a few weeks up to a couple months.

However, if you wish to keep, grow and deepen the flavor of your brine over the long term, a ceramic paocai jar is a much better option. One reason is aesthetics: The more vegetables you ferment in the brine, the more buildup you get in the bottom of the jar. This yellowish-white powder is spent bacteria from fermentation and totally natural, but it’s not totally appealing.  A more important reason to opt for the ceramic jar, though, is that it blocks all light from the pickles, which nurtures a healthier brine over time, allowing you to develop an intensely—but always pleasantly—fragrant and flavorful brine.

Although you won’t be able to see what is happening with a glance at the ceramic jar, you will be able to hear it happening! As fermentation kicks in, bubbles build and gas escapes the lid of the heavy ceramic jar, you’ll hear a distinct burble—a burp, if you will—every so often. Don’t be alarmed, it’s just the vegetables telling you they are becoming pickles.

The two jars above both hold Sichuan pickles. The brine in the glass jar has fermented several batches, and spent yeast is building up on the bottom. This does not affect the taste of the pickles, as they mostly float above it, but it does impact the aesthetics. That is one reason—along with the opaque, sun-blocking material—that we prefer a ceramic jar for a long-term brine.

In general, I  pickle vegetables we plan to eat in a week or two in our glass pickle jar, refilling it each week with a new batch of vegetables. I can usually maintain a brine like this for a month or two before I’m longing for a fresh, clean brine for the shiny glass jar. I use the ceramic paocai jar to make larger batches of pickles or to create a brine I want to maintain for several months (or goal: years!), building an intense flavor profile that quickly turns vegetables into tasty pickles.

As you add and remove vegetables from the jar, you may find that you need to top off the brine to keep the jar full. Do this by adding filtered or boiled-and-cooled water and salt in the same concentration as your original brine. You do not need to dissolve the salt first, just add it, and perhaps a bit more sugar and a slug of hard liquor, to the jar and let it do its thing. Even if you do not need to add more water to reach the imaginary water line at the bottom of the neck, add a bit of salt when you add fresh vegetables, to lessen the chances of welcoming new microbes that can cause kahm yeast.

What Is Kahm Yeast?

My biggest problem with lacto-fermentation in my early years was that, unlike a vinegar brine, as it progresses, the salt brine starts to go cloudy. Sometimes it even forms a white, moldy film 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 white film creeped me out, and I thought I was doing something wrong.

But one summer in Sichuan proved me wrong. The owners of Sichuan food brand Youjia took Fongchong and me to eat at a high-end restaurant with Paocai 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 hard to determine why this sometimes occurs (and why it mostly doesn’t), as I’ve had it happen in different seasons with difference salt concentrations and different vegetables. Experts say that kahm yeast is more likely to grow with sweeter vegetables like carrots and chilies in the brine, and also with lower salt concentrations. In any case, it does not ruin the pickles. You can simply remove it with a spoon and top the jar up with more filtered water and salt. I have also been known to soak it up with a paper towel placed on the top of the brine, as it catches more of the offending film than a spoon. Sprinkle a granulated salt such as kosher on the top to deter regrowth there.

Unfortunately though, once a brine has kahm yeast it is hard to get rid of it entirely and it often grows back. This does not bother some people, so they just remove it to get to their pickles. I sometimes do this as well; rinse the pickles and they are as good as new. But in truth I find kahm yeast off-putting. What I usually do instead is remove the top brine, unpack the pickles into a glass container along with some of the bottom brine, and refrigerate them. Then I simply start over in the paocai jar with a fresh brine and fresh batch of vegetables. Make sure you have thoroughly cleaned and sanitized the jar before you start a new batch. Chinese picklers often wash out the jar with some hard liquor, just to make sure.

Cleaning the Water Moat on a Paocai Jar

For either glass or ceramic paocai jar, don’t forget that you must keep the moat at least partially filled with clean water at all times, as this seals the jar, keeping oxygen at bay while allowing fermentation gases to escape. The moat will collect dust from the air, so every few weeks you’ll want to sop it up with paper towels and clean the moat and lid. Wash the lid with soap and water and dry well. You can carefully employ a soapy sponge for the moat, but I prefer to wipe it with some of the Chinese baijiu (or other high-proof liquor) that goes in the brine.

Be careful every single time you take the lid off the jar to not let water from the moat drip into the jar. I have a maneuver where I lift the lid slightly out of its water, shake it back and forth, then pull it quickly up and away from the jar before any water can drip.

Creating a New Pickling Brine With an Older One

When you have a mature brine that you like, you can transfer it, or part of it, to a new jar, say from glass to ceramic, or  to a second jar to kickstart an additional ferment. When people say they have kept their brines for years, they generally mean at least part of the brine is from an original ferment. You want to use the superpower of that mature ferment to influence the new one with its already established good bacteria.

Here I am starting a new jar of pickles by transferring some of the brine and even some of the pickles from the mature brine to the new jar. Just a cup or so of the mature brine will jumpstart the new ferment. The brine will then be topped up with newly made brine in the original salt concentration, plus additional sugar and liquor as per the recipe.

This healthy mature brine—which is several months old—still looks and smells sour in a good way. Its pink hue comes from the red radish and red chilies that have been among its many batches of  vegetables. Otherwise, it would generally be a more yellowish color.

The “forever” brine welcomes new vegetables for a new batch.

A mature brine will work its magic on cabbage in just a couple days. The combination of crunchy sour cabbage and spicy hot chili oil cannot be beat.

Additional Questions About Making Sichuan Pickles

What if I can’t use liquor in my paocai brine?

• Besides contributing to the flavor, it’s said that the high-proof liquor also helps deter bad microbes. However people have been fermenting vegetables for millennia without liquor, so you can simply leave it out.

Can I add other spices besides Sichuan pepper?

• Yes! Sichuan pepper is almost always used in Sichuan pickles, but some cooks add additional Chinese spices to the brine. You can add them directly to the jar or steep them in the brine and then remove them. I will say that when I’ve used multiple spices, I’ve had trouble getting the vegetables to ferment. I believe that one of the spices I used was acting as a preservative—but I don’t know which one!

What if my vegetables never ferment/sour?

• This most likely means that your salt concentration is too high and you’ve killed off all the bacteria, not just the bad kind. Try a lower salt concentration for your next batch.

What if my ferment grows mold?

• A thin white layer of kahm yeast is normal (see photo above), but any other type or color of mold is bad news. Throw it out! The same applies if the brine smells bad or rotten. A good brine will smell sour in a pleasant way.

How long will fermented vegetables last if I remove them from the jar and refrigerate them?

• Seemingly forever! Just as with the pickles in the paocai jar, let your eyes and nose be the judge of their shelf life.