Use an airtight container
Moisture is the enemy of crisp cookies. As soon as you open a pack, move the cookies to an airtight steel or glass container and close the lid properly after every use.
Keep them cool and dry
Store the container away from the stove, sunlight and the kitchen sink. A cool, dry shelf works best, especially in humid weather.
Don’t mix different cookies
Strongly flavoured cookies such as jeera can pass their smell to sweeter ones. Keep each flavour in its own container.
Refresh soft cookies
If crisp cookies turn slightly soft, warm them in an oven for a few minutes and let them cool completely before storing again.