Weevils in grain

Hello,

I regularly grow barley grass and seem to have a lot of problems with weevil infestation in the barley grain. I have tried sourcing the organic grain from various places. I just purchased and received a large quantity of barley grain today (from an online organic grain and seeds store) and it has live weevils already. What can I do to salvage the grain and prevent the weevils multiplying and destroying the grain?

I have heard of freezing the grain for 4-5 days but I have also heard that this just makes the eggs dormant and they will hatch when the temperature rises. Does freezing destroy the eggs or make dormant?

My other concern is freezing and defrosting might create moisture which will be bad for storing grain.

Thanks Heaps!