Since discovering fermented tofu, I have been using it a lot. Whether it is in soups, marinades, or as a dipping sauce, it can be used in many dishes to add extra flavor, umami, and some cheesiness.
The thing is, fermented tofu is not that easy to find and let's be honest, I wanted to learn how to make my own. Here is a guide on how to make fermented tofu (also called chao) from scratch!
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 to make fermented tofu appeared 200 BC in China.
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 takes a strong flavor, that reminds me of a strong camembert.
What's great about chao is that it keeps for months, if not years in its brine!
HOW TO MAKE CHAO?
Making chao is easy but requires some patience!
Before starting: As with most fermented recipes, taking care of hygiene is critical to the success of the fermentation process. So I recommend using gloves while handling the tofu to prevent bad bacterias.
It starts with the tofu that is boiled for a couple of minutes in salted water. This step not only helps kill some bacterias, but it also helps the tofu drain more water.
Next, you want to place your tofu on several sheets of kitchen paper towel, cover with more paper towels, and place a weight on it to press it and remove excess water. I usually use a large iron skillet that is quite heavy. Leave your tofu like this for about 1 and a half hours and change the paper towel as needed if it becomes too wet.
Next, cut your tofu into 1-inch cubes. Place them on a plate lined with kitchen paper towel, then place another piece of paper towel on top, and cover the whole plate with plastic film.
Now you want to let the tofu ferment for about 2 days at 77-86°F (25-30° Celcius). So as you can guess this recipe works best in the summer, but can also be done during winter if you have a warm spot in your house.
After 2-3 days, the tofu should be slightly orange and a bit stinky (see photo below). It may have some white mold as well, that's okay. If you see black or blue mold, just scrape it off. Quick tip: if the tofu is not stinky enough when you put it in the brine, you will end up with a mild chao, if it is already stinky your chao will be stronger.
The hardest part is now done!
The tofu now contains some natural cultures and molds that will work during the fermentation process.
To prevent the tofu from going bad, we need a brine. It consists of boiled water mixed with salt, sugar, and rice wine (or vodka). You place the tofu cubes in glass jars and cover with the brine.
Optionally, you can dip each tofu cubes 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 the chili.
Once your jars are full, secure with a lid and place them in a dark place at around 68°F (20°C) for at least 3 weeks. The longer you let it ages, the stronger and softer it becomes. I found that after 6 weeks, the tofu is already creamy and has a nice cheese flavor.
HOW TO USE CHAO?
Chao is often used to make dipping sauces, it is mashed and mixed with some lime juice, sugar, and chili. It can also be eaten with rice, used to make marinades, or stirred into soups. May I also recommend trying to make cheesy sauces or add a bit to vegan cheeses for extra flavor?
I hope you enjoyed this guide and will start to make your own!
Let me know in the comments if you try this recipe!
How to Make Fermented Tofu (Chao)
- 1 pound firm tofu, cut in half
- 4 cups water
- 1 tablespoon salt
- optional: ¼ cup chili flakes
- 1 and ½ cup water
- 3 tablespoon salt
- 1 tablespoon sugar
- ¼ cup vodka (or ½ cup rice wine)
- Before starting: I recommend using gloves when handling the tofu to prevent bad bacterias and mold from growing.
- Bring 4 cups of water with one tablespoon of salt to a boil in a medium size sauce pan. Once boiling, add the tofu and boil for 4 minutes.
- Remove the tofu from the water and place it on a few sheets of kitchen paper towel. Top with more kitchen paper towel and place a heavy weight on it to press the tofu and remove excess water. I usually use an iron skillet. Let it drain for about 90 minutes, changing the paper towel as needed if it becomes too wet.
- Line a large plate with two layers of kitchen paper towel, or a clean towel. Cut the tofu into 1-inch cubes and place the cubes on the plate, leaving about 1 inch between each cube, so they don't touch each other. Top with another sheet of kitchen paper towel and cover the whole plate with plastic film. The plastic film will prevent bad bacterias from reaching the tofu.
- Place the plate in a dark place at 77-86°F (25-30°C) and let it ferment for 2 to 3 days. The tofu will have taken a light orange color and will have a stinky smell. You may also see some white mold as well, this is okay. If you see blue or dark mold, scrape it off.
- Prepare the brine: combine 1 and ½ cup of water with the salt and sugar in a saucepan. Bring to a boil and boil for 1 minute. Once boiling, remove from heat and let it cool completely. Add the vodka and stir to combine.
- Transfer the stinky tofu to clean glass jars. If you want to make it spicy, dip each tofu cube in chili flakes before putting it in the jars. Pour the brine into the jars to cover the tofu. Close the jars with a lid and place in a dark cool place (around 68°F - 20°C) for at least 3 weeks. The longer you let it ages, the stronger and softer your tofu will be.
- For extra flavor, you can add about ½ teaspoon of sesame oil into each jar after the 3 weeks have passed.
- Use this fermented tofu to make dipping sauces, to top rice, add to vegan cheeses, use in marinades, soups, etc.