Today I opened up two 15 litre buckets of Black Beans after 5 years in storage to check viability. Sealed in Mylar bags with oxygen absorbers the beans showed no sign on insect infestation and seemed as fresh as the day I first purchased them. Will be trying black beans and rice made from 5 year old beans later in the week. This is the only way to store successfully for long term use. In Mylar bags with oxygen absorbers, then sealed plastic food grade buckets with O-ring seals.

sealed buckets
showing mylar bag seled
size of the bag used
beans with oxygen absorber