Tofu, which is also sometimes referred to as bean curd, is a soy milk product that has been known for many years to be a healthy food that is low in calories but high in protein. In the homesteading and prepping sectors, we ferment many foods to extend their storage capability and provide us with a means to prepare these foods in advance and have them available when we need them. Is tofu one of the foods that can be fermented in this way, and if so, how long will it last, and does it expire?
Fermented tofu will not keep indefinitely but has a significant shelf-life of between six months to a year. The fermentation process continues, even if refrigerated, and it will reach a point beyond which it will be inedible. This expiration date is often determined by the type of ferment, as some ferments can take six months just to reach maturity.
Tofu is an important protein source for homesteaders and preppers since it can be used as an alternative to meat protein when that is in short supply. In order to have this protein source available when we need it, we need to know how to store it long term. The best way to achieve this with tofu is to ferment it, which not only improves its longevity but also enhances its flavor!
How Long Will Fermented Tofu Last?
Tofu in its normal state will generally only last 5 days to a week in the fridge once the packaging has been opened. It lasts a bit longer in the freezer, and you can probably get it to last between 3 and 5 months.
Freezing is not always a feasible method of preserving foods, especially in homesteading or off-grid living. In these circumstances, fermenting is the best method to extend the shelf life of your tofu.
There are many methods of fermenting tofu, and the various methods result in various forms of tofu that can last for varying amounts of time.
Generally, fermented tofu, if refrigerated once the fermentation has reached the desired level, can last for six months easily in an airtight jar. In some instances, the tofu fermented and stored in this way has been known to last for up to a year.
As with any fermented foods, you need to test the product when you open it to determine if it is still good for consumption. Your best tools for determining this fact are your senses of vision, smell, and taste.
With the visual inspection, you will be able to tell if any mold has invaded your fermented tofu and started to grow on it. This can normally be prevented by making sure it is below the brine solution when you store it in your fridge. If it has developed any mold growth, it would be safer to discard your tofu in the interest of health and safety.
The smell detection is to take a whiff and see if it smells offensive or rotten. Fermented tofu can have a strong odor similar to a block of strong cheese, but a rotten smell is definitely an indication that the tofu has gone off and should not be eaten.
Taste is the last sensory evaluation to try if the tofu has passed the other two tests. If the tofu tastes anything other than what you would expect it to taste like, then you should probably discard it. For those who are new to tofu, fermented tofu is a lot like a strong cheese; it tastes better than it smells. So if you taste test the fermented tofu and it tastes bad, then rather toss it out and try again.
What Is Tofu?
Tofu is a product made from processed soy milk, and it originates from China, where it has been a staple food for generations.
The method of making tofu is similar to the method of making cheese from cow’s milk, but in this case, the cow’s milk is replaced with soy milk. Soy milk is derived from the soya beans that need to undergo a process to produce soy milk, which is not our topic for discussion today.
To produce tofu, the soy milk needs to be prepared, then coagulated, which forms curds, and it is these curds that are pressed into blocks and become tofu.
The methods of coagulation vary from region to region in the Far East, but traditionally in china, the coagulation was achieved by adding calcium sulfate, otherwise known as gypsum, to the soy milk.
The use of calcium sulfate results in tofu that is not only high in protein from the beans but also high in calcium.
The gypsum causes a separation or a coagulation to separate the curds and whey. Curds are the solid components of the soy milk, which become the tofu, while whey is the water component and is no used as part of the tofu.
The curds are then pressed into molds to remove excess whey and left to dry and set into blocks of tofu, which are then ready to eat or for sale.
What Is Fermented Tofu?
Fermented tofu, like any other fermented food, is tofu that has undergone a process of fermentation, which is very similar but differs slightly in method to fermenting other food types.
Fermenting tofu to preserve it is a process that has been used in ancient times in China. Records of this process date back to 200 BC in China, so it has been a common practice with tofu for centuries.
The process to produce fermented tofu includes letting it air dry at room temperature for 2 to 3 days, usually covered with a breathable cloth such as cheesecloth. This allows airborne bacteria to attach themselves to the tofu and begin the fermentation process.
After the air dry period, the tofu cubes are placed in a brine solution mixed with sugar and rice wine. This solution helps to kill off the bad bacteria while promoting the growth of the good, healthy bacteria and promote the fermentation process.
The tofu is then left in the brine mixture to ferment for a minimum of another 3 weeks. Some people prefer the fermentation to go for 6 weeks before they consume it. The longer the fermentation is left to continue, the stronger the flavors will get.
The fermenting process will continue if left at room temperature, so the tofu is normally put in the fridge to cool the tofu and slow down the fermentation process once the desired flavor is reached.
Fermented tofu is often flavored with various additional flavors depending on the preference of the maker or the dish that the fermented tofu will be used in. A common flavoring is coating the tofu cubes in chili flakes or chili powder before placing it in the brine mixture.
This particular flavoring will give the tofu a hot and spicy taste making it suitable for use in a dipping sauce, stirred into a soup, or used in a marinade.
Conclusion
Fermented tofu is a great source of protein and calcium, as well as the bacteria that contribute towards good gut health. As a way to preserve tofu for later use, fermentation is a great method and also a way of flavoring the tofu in a way that you like.
The 6 month to a year lifespan of fermented tofu significantly increases its normal expiration time of a few days.
Tofu is a great alternative protein product to meat, especially if you are a homesteader or prepper that prefer a vegan lifestyle over the rest of us flesh-eaters!
