The shelf life of soybeans depends heavily on their moisture content and storage conditions.
Storage of Dry Soybeans
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Low Moisture (13% or less): Under cool conditions (below 60°F or 15.5°C), soybeans with a moisture content of 13% or less can generally be stored for about 6 months without significant mold issues. One source mentions storing soybeans at around 11% moisture for over a year and a half in a steel grain bin with ventilation. [Source: Reddit, farming subreddit] However, this is an exception and not a guaranteed outcome. As moisture increases, storage time decreases.
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Higher Moisture: With higher moisture levels, the soybeans will spoil faster due to increased risk of mold growth.
Other Soybean Products
It's important to distinguish between whole soybeans and processed soybean products:
- Soy milk: Unopened soy milk can last for about a month in the pantry past its expiration date, while refrigerated unopened soy milk will last even longer. Once opened, its shelf life is significantly reduced. [Source: Quora]
- Soybean sprouts: Soybean sprouts are highly perishable. They should ideally be used within 3 days of purchase, or even sooner. [Source: Food52]
- Dried Soybeans (for human consumption): The shelf life of dried soybeans intended for human consumption will vary depending on storage conditions (cool, dry, and airtight container). Specific times are not readily available in references.
Factors Affecting Shelf Life
Several factors influence how long soybeans remain safe and usable:
- Moisture Content: The single most important factor. Lower moisture significantly extends shelf life.
- Storage Temperature: Cooler temperatures slow down spoilage processes.
- Storage Conditions: Proper storage in a cool, dry, and well-ventilated area helps prevent mold and insect infestation.
