Learn why a crust can form on stored besan. Discover how exposure to air and moisture can cause the top layer to harden over time.
1 Answer
Besan, or gram flour, forms a crust at the top during storage due to moisture loss from the surface, causing it to dry out and harden. Exposure to air also contributes to oxidation and the development of a crust.
Detailed Explanation:
Besan, being a finely ground flour, is hygroscopic, meaning it readily absorbs moisture from its surroundings. When stored, the surface layer of the besan is directly exposed to the air. This exposure leads to the evaporation of moisture from the top layer, causing it to dry out. As the moisture evaporates, the particles of besan bind together more tightly, forming a hard, crust-like layer. Furthermore, the oils present in besan can oxidize upon exposure to air, contributing to the hardening and crust formation. Improper storage conditions, such as leaving the container open or storing it in a warm, humid environment, exacerbate this process. The crust doesn't necessarily mean the entire batch is spoiled, but it indicates that the surface has been affected by moisture loss and oxidation.
Pro Tip:
To prevent besan from forming a crust, store it in an airtight container in a cool, dry place. Consider adding a bay leaf to the container; it helps absorb excess moisture and deter pests, further preserving the quality of the besan.