If you still have them flying around you didn't get them all. They like to spin little webbings in the corners of boxes,around the lids of canisters, and in cracks. so dont just look into the food itself for them- look for the slightest inkling of webs. Also, if the shelf can be removed, take it out and clean the lip and around the back edges of the shelf. It is best to throw away ALL open products if you are in doubt. (you can canister it, but you will be ingesting any left over bugs that suffocate.)
These bugs come into our homes in food from the grocery store, so watch dates on packages.The older the food, (or the longer it sits in your shelves)the more likely there is a chance they are replicating.
Dont over look spices. If I remember correcly they really liked red peppers! I believe my mom's infestation started with pet bird food/seed.
I beleive grain moths are different than the moths that eat clothing- I don't think they interchange their diets.