When purchasing pre-cleaned and pre-packaged grain, it is safe to assume that it is pest free. Bagged foods should then be packaged in an oxygen free environment for long term storage to prevent infestation.
    If food is infested with weevil, it may be treated two ways. Adult insects can be destroyed by placing the food in a freezer at or below 15oF for 2 to 3 days. This may not kill all the larvae and eggs so repeat this process after a month. All insects, eggs, and larvae will be killed if frozen at 10oF for 2 to 3 days.
    Insects can also be destroyed by heat. Heat the grain, layered 1/2 inch or less deep, on a pan in an oven at 130o-140oF for 30 to 60 minutes. Higher temperatures and longer periods of time will reduce germination and, perhaps, handling quality of subsequent flour milled from the grain.