What can I do so that my frozen peas don't freeze into one big lump after I open the bag? I usually have to bang the bag on the counter a few time to break up the lump, and even then, it's not very effective. I close the bag securely and even put a rubber band around it but it doesn't seem to help. I just want the peas to flow out like they do when the bag is new! Am I asking too much?