Storage
Can I freeze natto?
Check whether the maker recommends freezing and how to thaw and use that product. We do not give one shelf-life rule for every formulation, package and storage history.
How long does an opened pack last?
Use the package guidance and ask the manufacturer when it is unclear. Do not invent a new use-by date based on aroma, visible strings or an online photograph.
Can I taste it to see whether it is safe?
No. Harmful contamination is not reliably identified by taste, smell or appearance. Do not taste a questionable food to diagnose it.
How should I store a bought pack?
Follow the manufacturer’s storage, handling and date instructions for that exact product. A generic website answer should not override them.