How to Make Fermented Tofu (Chao)

For those unfamiliar with it, chao is a Chinese/Vietnamese condiment made from fermented tofu that has a funky and cheesy taste!

I discovered it several years ago in Vietnam, and since then, I have been using it in so many recipes. Whether it is in soups, marinades, or as a dipping sauce, you can use it in many dishes to add extra flavor, umami, and some cheesiness. I even used it as a base to make vegan cheese slices!

For the little story, I actually learned how to make it from my Vietnamese mother-in-law, who has been making it for decades. She gave me her (not-so) secret recipe, which requires just 6 ingredients and an easy process. To be honest, I was even surprised how simple it is to make it at home!

⭐️ Why You Should Try It

Naturally fermented.

While some fermented recipes call for starters or cultures, this one doesn’t! This means you won’t need any special ingredients to make it. The mold that grows on the tofu is completely natural. The process consists of letting the tofu ferment at room temperature for a couple of days before transferring it to a jar and covering it with brine. Then, all you have to do is wait.

And trust me, the wait is worth it because homemade chao tastes so much better than the jars available in Asian supermarkets!

Cheesy and packed with umami.

After the fermentation process, your tofu will magically transform into creamy cubes packed with a rich cheesiness, plenty of umami, and a touch of tanginess. It will no longer resemble or taste like traditional tofu – instead, it will have an almost aged cheese-like quality.

It keeps for months.

What’s great about chao is that it can be stored in its brine for months, if not years! I personally had a jar that I kept for over a year, and the chao was still perfectly good!

📘 What Is Chao?

Chao (which is its Vietnamese name) is tofu that is fermented for at least 1 month in a brine that consists of water, salt, and usually rice wine. According to some books, the technique of making fermented tofu appeared in 200 BC in China.

Now you may wonder, what does it taste like? Well, it is quite salty, sometimes spicy, and has a very soft texture, almost like a paste that you could compare to blue cheese. When Chao is fermented for a long time, it develops a stronger flavor, which reminds me of a strong Camembert.

🌶 Ingredient Notes

Tofu

Firm tofu makes the base of this recipe. I suggest checking your local Asian supermarket to buy tofu, as it’s often fresher and tastes better compared to brands found in regular supermarkets.

Which type of tofu to use: You should be using firm tofu or extra firm tofu (although I haven’t personally tried with extra firm yet). DO NOT use silken tofu for this recipe – it’s too soft and it would simply crumble into pieces.

Chili flakes (optional)

Two types of chao exist, the white kind and the orange/red one. The latter gets its color from chili flakes or red yeast rice! I personally like to season mine with Korean chili flakes, also known as Gochugaru. This not only adds a touch of spiciness but also gives the chao a vibrant orange hue.

Note: Feel free to omit the chili flakes completely!

🧂 Brine

To prevent the tofu from going bad, you will need to store it in a brine. Allowing the tofu to sit in a brine for a few weeks not only gives it a cheesy aroma but also changes its texture from crumbly to creamy. Here is what you will need to make the brine:

Water

Water makes up the base of the brine. I always use tap water and have never had any issues, but feel free to use bottled water if you prefer.

Salt

Along with alcohol, salt helps preserve the tofu for many months in the brine. Please do not try to decrease the amount of salt – doing this could cause your tofu to spoil quickly.

Note: I advise against using pink Himalayan salt as it can add a hint of pink color to the tofu. That makes it hard to tell if it’s mold or just the color of the salt.

Sugar

Sugar is not essential to this recipe, but it helps balance the saltiness.

Vodka or rice wine

Alcohol does two things: First, it acts as a preservative, helping the chao last longer. Second, it contributes to the flavor by helping break down the tofu proteins, creating umami-rich flavors.

Note: Traditionally, it’s rice wine that is used to make the brine. Since rice wine is not that easy to find and/or expensive, I replaced it with vodka.

Got rice wine? You can replace the vodka with 1/3 to 1/2 cup of rice wine with a 15-25% ABV.

🥣 How to Make It

Before starting: As with most fermented recipes, taking care of hygiene is critical to the success of the fermentation process. That’s why I recommend using gloves while handling the tofu to prevent bad bacteria.

1. Prepare the tofu

1. Boil the tofu. First, you need to boil the tofu in salted water for 3-4 minutes. This step not only kills possible bad bacteria but also helps the tofu drain more water.

2. Press it. Next, you want to place your tofu on several sheets of kitchen paper towels, cover it with more paper towels, and place a weight on it to press it and remove excess water. Leave your tofu like this for about 1 and a half hours, and change the paper towel as needed if it becomes too wet. Note: I usually use a large iron skillet for this step, but heavy flat plates or a tofu press will also work.
3. Dice it. Cut the tofu into 1-inch (2.5 cm) cubes and place them on a plate lined with two layers of kitchen paper towels. Leave about 1 inch between each cube, so they don’t touch each other.

3. Cover. Top the tofu with another sheet of kitchen paper towel and cover the whole plate with plastic film. The plastic film will prevent bad bacteria from reaching the tofu.

2. Let it ferment

Now comes the fun part, the fermentation!

1. Let the tofu ferment. Place the plate in a dark place at 77-86°F (25-30°C) and allow the tofu to ferment for 2 to 3 days.

Note: As you can guess, this recipe works best in the summer, but it can also be done during winter if you have a warm spot in your house. Near an electric heater or radiator, for example.

3. Add it to the brine

The tofu now contains some natural cultures and molds that will allow it to develop flavors over time in the brine. Keeping the tofu in the brine is essential to preserving it.

1. Prepare the brine. Combine 1 and 1/2 cups of water with the salt and sugar in a medium saucepan. Bring to a boil and boil for 1 minute. Once boiling, remove from the heat and let it cool completely. Once cool, add the vodka and stir to combine.
2. Coat the tofu with chili flakes. Optionally, you can dip each tofu cube in chili flakes. It makes the chao more flavorful and gives it an appealing orange color. If you plan on using chao to make cheeses, simply omit this step.
3. Add the tofu to the brine. Transfer the stinky tofu cubes to clean glass jars. Pour the brine into the jars to cover the tofu.

4. Let it ferment. Close the jars with a lid and place them in a cool, dark place (around 68°F – 20°C) for at least 3 weeks. The longer you let it age, the stronger and softer your tofu will be. I found that after 6 weeks, the tofu was already creamy and had a nice cheese flavor.

🥢 How to Use It

Chao is a versatile condiment that you can use as a seasoning in many dishes. Here are some ideas:

• Dipping sauce: Mash a cube of chao and mix it with some lime juice, sugar, chili, and a little bit of water to dilute. The sauce can then be used as a dipping sauce for steamed or boiled vegetables. You can even use it as a dipping sauce for summer rolls or grilled betel leaves!
• Vegan cheeses: Since chao is packed with umami and cheesiness, it’s perfect to add flavor to your vegan cheeses! Add half of a cube to vegan camembert or smoked cheese when blending the cashews for a deeper flavor!
• On top of rice: Add some chao on top of steamed white rice and slightly mash it using chopsticks. Chao will add saltiness and cheesiness!
• Stirred into soups: Perfect to take your soups or ramen to the next level, you can use it in place of miso.
• Marinades: Combine a cube of chao with soy sauce, sugar, and sesame oil to make a rich and cheesy marinade for tofu, seitan, or tempeh.
• In stir-fries: Mash a cube of chao with a few teaspoons of the brine and a teaspoon of sesame oil before adding it to stir-fried vegetables such as morning glory, spinach, or broccolini!
• As a salad dressing: Combine it with equal parts of mayonnaise and vegan cream cheese to create a creamy salad dressing. You can then season it with chopped garlic, ground black pepper, and salt to taste.

💬 FAQ

I hope you enjoyed this guide on how to make fermented tofu at home! It’s much easier than it may sound, and it’s a super fun process to see bland tofu transform into creamy and cheesy cubes!

🥡 More Asian Condiments

Easy Sweet Chili Sauce

Vegan Fish Sauce

Easy Hoisin Sauce

Vegan Oyster Sauce (Stir Fry Sauce)

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