Dried red chilies turn brittle primarily due to moisture loss during the drying and storage process. This loss of moisture makes the chili pods fragile and easily breakable.
The primary reason dried red chilies become brittle is dehydration. When chilies are dried, the moisture content is significantly reduced to prevent spoilage and extend shelf life. This process makes the cell walls of the chili pods less flexible. Over time, especially if stored improperly, the chilies continue to lose moisture, causing them to become increasingly brittle. Exposure to air and sunlight can accelerate this process. The natural oils within the chili also evaporate, further contributing to the loss of pliability. The combination of these factors results in the characteristic brittle texture.
To prevent dried red chilies from becoming brittle, store them in an airtight container in a cool, dark place. Adding a desiccant packet (like those found in vitamin bottles) can help absorb excess moisture and prolong their shelf life and flexibility.