Fermented bean curd, also known as fermented tofu or doufuru, is a type of preserved tofu that has been fermented with the help of mold. It originates from China and has a rich umami flavor and soft, creamy texture. Fermented bean curd is valued for its unique taste and versatility in cooking. However, like any perishable food, it has a limited shelf life. So how long does fermented bean curd last? Here is a detailed guide on the shelf life and proper storage of fermented bean curd.
How is fermented bean curd made?
Fermented bean curd is made by inoculating fresh tofu cubes with spores of certain species of mold, usually Actinomucor elegans, Mucor racemosus or Rhizopus oligosporus. The tofu is then allowed to fully ferment and develop air pockets and a creamy consistency. This process can take several weeks or even months. Once fully ripe, the fermented bean curd is then packed in brine made with rice wine, salt, and other seasonings.
The fermentation process preserves the tofu and gives it a unique tangy, cheesy flavor. The mold breaks down proteins into amino acids and fats into fatty acids, producing compounds that provide the signature taste of fermented bean curd.
Unopened fermented bean curd
When properly stored, unopened fermented bean curd that is still within the manufacturer’s printed expiration date has an excellent shelf life. Unopened jars can last:
- At room temperature – 6 to 12 months past the printed expiration date.
- In the refrigerator – Up to 2 years past the printed date.
- In the freezer – Up to 2 years when continuously frozen.
The brine acts as a preservative to inhibit mold growth and bacterial spoilage. Refrigeration and freezing further slow down spoilage. As long as the jar seal remains intact, commercially packaged fermented bean curd stays fresh for quite a long time past its expiration date.
Opened fermented bean curd
Once opened, fermented bean curd has a much shorter shelf life. This is because it is exposed to air, contaminants, and higher temperatures. Here is how long opened fermented bean curd will last:
- Refrigerator – 2 to 4 weeks
- Freezer – 2 to 3 months
It’s important to store opened fermented bean curd properly in airtight containers to get the maximum shelf life. The brine may also need to be topped off to cover the bean curd completely.
Refrigerator
Keeping opened fermented bean curd refrigerated at 40°F or below is the best way to maximize its shelf life. The cold temperature significantly slows bacterial growth and chemical reactions. With proper refrigeration, opened jars can last 2 to 4 weeks past the expiration date.
Make sure to seal the jar tightly or transfer the contents to an airtight container. Ensure the bean curd cubes remain fully submerged in brine by topping it off as needed. Keep the container towards the back of the fridge where temperatures are coldest.
Freezer
For even longer storage, you can freeze opened fermented bean curd. At a steady 0°F or below, bacterial and enzymatic activity halts almost completely. Frozen and thawed properly, fermented bean curd can keep for 2 to 3 months past when you opened it.
Transfer the cubes and brine into an airtight freezer bag or container, removing as much air as possible. Lay flat in the freezer to quick freeze initially. Once solid, you can stack or stand up the frozen containers. Defrost in the refrigerator before use.
How to tell if fermented bean curd has gone bad?
Despite proper storage, fermented bean curd can still spoil eventually. Here are signs that fermented bean curd has gone bad and needs to be discarded:
- Appearance: Bean curd looks moldy, mushy or discolored.
- Texture: Very soft, mushy cubes.
- Smell: Fermented bean curd normally has a pungent cheese-like smell. If it smells unpleasantly sour or rotten, it has spoiled.
- Taste: Very bitter, sour, or unpleasant flavor.
As fermented bean curd passes its prime, you may notice some changes even if it has not completely spoiled. The cubes may become softer and the brine cloudier. The pungent smell and flavor will also become stronger. At this point, it is still safe to eat but the quality is diminished.
How to store fermented bean curd properly?
Proper storage is key to maximizing the shelf life of fermented bean curd. Here are some tips:
- Purchase fermented bean curd from a reputable Asian grocery store and check the expiration date and packaging.
- Store unopened jars at room temperature away from direct sunlight.
- Once opened, transfer any leftover fermented bean curd to an airtight container and refrigerate.
- Always make sure fermented bean curd is fully submerged in brine by topping off liquid as needed.
- Use clean utensils to handle fermented bean curd to prevent contamination.
- Freeze for longer term storage. Defrost overnight in the refrigerator before use.
- Consume refrigerated bean curd within 2 to 4 weeks and frozen within 2 to 3 months.
Avoid leaving fermented bean curd out on the counter or at higher temperatures for too long once opened. This accelerates spoilage. With proper handling and storage, fermented bean curd can stay fresh and flavorful for months, even after opening.
Conclusion
Fermented bean curd is a fermented food with a long shelf life. Unopened commercially packaged jars keep for up to a year past the printed expiration date when stored properly. Once opened, fermented bean curd will last for 2 to 4 weeks refrigerated and 2 to 3 months frozen. Keeping it cold and in an air-tight container is key. Signs of spoilage include mold, mushy texture, unpleasant aromas and sour flavor. With proper storage and handling, opened fermented bean curd can continue providing its signature rich, savory taste for weeks to months, allowing you to enjoy this versatile Chinese ingredient for your cooking needs.
