Alternately, put grains in a dehydrator for 24 hours. I have a Nesco dehydrator that I got on sale for $40 this time of year three years back. It has been wonderful and we have used it a TON! On the downside it is plastic, but on the upside we could afford it. :) And it was made in the USA. I dehydrated my grains for 24 hours on the lowest setting. After that much time elapsed, they were more than done, even though I didn't stir them once. Very convenient.
However you dehydrate your grains, allow them to rest until they come to room temperature. Then transfer them to airtight containers in the refrigerator. T