Making Duo Jiao: Hunan Fermented Chopped Chilies-Final Update

The more I cook Hunan food, the more I realize that some of its most distinctive flavors don’t come from complicated recipes. They come from the ingredients that Hunan cooks keep on hand. Duo Jiao (剁椒), chopped salted chilies allowed to ferment until they become tangy, savory and deeply aromatic, is one of those ingredients.

You can buy jars of Duo Jiao in a Chinese market, and I have. But once I began using it in dishes such as Hunan steamed fish and stir-fries, I became curious about making it myself. The basic process couldn’t be much simpler: fresh chilies, salt, garlic and time. What happens over the next several days is the interesting part. The chilies soften and release their juices, the brine becomes cloudy, and the sharp smell of fresh peppers gradually develops into something much more complex.

Here’s the perfect dish to use your Duo Jiao, Hunan Stir-Fried Shrimp with Chopped Green Chilies (青剁椒虾)

So I decided to make a batch and document the process from beginning to end. This isn’t a shortcut version or an attempt to reproduce the flavor with vinegar. We’re going to let fermentation do the work.

**Day One**: Fresh chilies, garlic and salt before fermentation begins.

A piece of parchment and a glass fermentation weight keep the chilies submerged beneath the developing brine.

**Day Two**: The chilies have already begun releasing their liquid, creating a layer of brine above the peppers.

**Day Four**: The fermentation is well underway. The chiles have softened and settled, and the aroma has become noticeably tangy, savory, and complex.

I’m documenting this batch as it ferments and will continue updating this post with photographs, observations, and the complete method as the process develops.

**Day Seven:** The chilies have softened and settled considerably, while the brine has begun to clear. The aroma is pleasantly fermented and noticeably more rounded. Fermentation continues.

I tried the chilies last night as a dipping sauce with a bit of toasted sesame oil and black vinegar and they were crunchy and delicious. Really well rounded flavor, but I’m thinking they have another week to go.

My first batch of Duo Jiao — a useful experiment in traditional Hunan fermentation. I’m now starting a larger batch, with the chilies finely chopped rather than sliced, which should produce something closer to the traditional texture.

Starting a new larger batch with a water well fermentation system. I think it will allow me to make larger batches and hopefully give me better control over the fermentation process.