Paocai (Sichuan Fermented Pickled Vegetables)

Paocai is the Sichuan tradition of lacto-fermented vegetables, and it is unlike any other pickle on this site. Where most pickles here use vinegar for preservation, paocai relies on salt and time. Vegetables are submerged in a seasoned brine and left to ferment naturally, producing a clean, tangy sourness from lactic acid bacteria rather than from vinegar.

The tradition centers around a single jar of brine that is maintained, fed with new vegetables, and reused for months, years, or even decades. In Sichuan households, a paocai jar is a living kitchen staple. Some families pass their brine down through generations.

What is paocai?

Paocai (literally “soaked vegetables”) refers to vegetables that have been naturally lacto-fermented in a seasoned salt brine. The brine typically includes Sichuan peppercorns, star anise, dried chilies, ginger, and sometimes bay leaves or other aromatics.

The fermented vegetables are crisp, tender, and refreshingly sour. They are eaten raw as a side dish, or used as a cooking ingredient in other Sichuan dishes. Paocai rou si (stir-fried shredded pork with paocai) and fish-fragrant eggplant both use paocai as a key ingredient.

How paocai differs from other Asian pickles

Most pickles are a finished product. You make them, jar them, and eat them. Paocai is an ongoing process. The jar is never empty. As you remove fermented vegetables, you add fresh ones. The brine gets stronger and more complex over time, and each new batch ferments faster than the last because the bacterial culture is already established.

This “infinite jar” approach is similar in concept to a sourdough starter. The older the brine, the better the flavor.

Starting your first jar

If you have access to mature paocai brine from a friend or family member, use it. Adding a cup of established brine to your jar will kick-start the fermentation and produce better results faster. This is the traditional way new jars are started in Sichuan.

If you are starting from scratch (the recipe above), the first batch will take longer, typically 7 to 14 days depending on temperature. Subsequent batches will ferment in 1 to 3 days once the brine is established.

Which vegetables to use

Almost any firm vegetable works. Common choices in Sichuan include:

• Cabbage (ferments in about 1 day in mature brine)
• Long beans (about 1 week)
• Daikon radish (about 3 days)
• Carrots (about 3 days)
• Cauliflower (about 3 days)
• Red chilies (about 1 week, also flavors the brine)

Avoid very watery vegetables like tomatoes or zucchini, especially when your brine is young. They dilute the salt concentration and can cause problems. Cucumbers ferment well but are best done in a separate jar because they ferment quickly and can make the main brine cloudy.

Tips for maintaining your jar

Keep vegetables submerged. Anything above the brine line will mold. Use a small plate or weight to keep everything under the liquid.

Keep the jar clean. Never reach into the jar with your hands or dirty utensils. Use clean, dry tongs or chopsticks.

Watch the salt level. If the brine starts to taste weak or the vegetables are not fermenting properly, add a tablespoon of salt dissolved in a small amount of water. The brine should taste noticeably salty, like seawater.

Add aromatics periodically. Refresh the Sichuan peppercorns and dried chilies every few weeks to keep the flavor lively.

A little alcohol helps. A splash of baijiu (Chinese grain spirit) added occasionally helps prevent surface mold. This is a traditional Sichuan technique.

Room temperature for fermenting, fridge for pausing. Keep the jar at room temperature when you are actively fermenting. Move it to the fridge if you need to take a break from adding vegetables. The cold slows fermentation almost to a stop without killing the culture.

The paocai jar

Traditional Sichuan paocai jars are ceramic with a wide mouth and a moat around the rim. The lid sits in the moat, which is filled with water, creating an airlock that lets fermentation gases escape while keeping air and insects out. These jars are available online and at some Chinese kitchen supply stores.

A glass jar with a loose-fitting lid works fine for beginners. Avoid metal lids that will corrode from the acidic brine.

Storage

An active paocai jar at room temperature is always in use. If you need to pause, seal it and refrigerate. The brine will keep in the fridge for months. To restart, bring it back to room temperature and add fresh vegetables.

Individual batches of fermented vegetables can be removed from the brine and stored in a separate container in the fridge for up to 2 weeks.