I decided to open up some rice we vacuum sealed in Mylar and a 5 gallon bucket. If you want to know how to store your own grains this way click here: Sealing Mylar bags with oxygen absorbers in 5gal buckets for long term food storage
Here is what we have after opening the bucket. The seal on the mylar still looks good. I recommend labeling the bucket and the bag in side.
When I cut the mylar the rush of air inside just verified that my seal was good.
The rice looked and smelled fine. No issues.
Here is where we got our supplies and what we used.
USA Emergency Supply
18-01-001 Mylar Bags – Mylar Food Storage Bag 20in. x 30in. (5 mils thick)
18-06-002 Food Storage Oxygen Absorbers D500 (500cc) 100 count