Tofu can go bad if it is left open, not refrigerated properly and left in unchanged water. The best way to keep your tofu from going bad is to keep it chilled in the refrigerator and change the water routinely.
Here are some helpful tips to prevent you from eating tofu gone bad!
First of all, you should always store your opened tofu in an air-tight container in the refrigerator. However, you must place the tofu in clean water and change it everyday in order to keep the tofu from going bad. You can always tell if the tofu is spoiled by its smell. If there is no smell, then the tofu is good to eat, but if there is a sour aroma to the tofu you should definitely toss it out.
Refrigerated tofu types can be stored unopened for two months in the refrigerator. However, if you open it up, you may only have a week to consume it before it spoils. Tofu can also be placed in a freezer and frozen for up to three months.
Non-refrigerated kinds of tofu have a much longer shelf-life and if left unopened can be stored in the pantry for up to one year. Most tofu packages have a date of expiration and should be adhered to. It is wise to check the date before purchasing your package of tofu.