Does anyone know if this is possible, and if it is...how would I go about doing it?

Hi! Do you mean storing it in the freezer? I always store my flour in the freezer and pull it out when I need it. It does not freeze and I am guaranteed it will last until the expiration date. I just keep it in the original package. I am guessing Jiffy Mix would be the same.

Sugar lasts forever, so I just store it in a plastic container in my cabinet.

I have frozen flour and cake mixes before, I just put the flour in a ziploc bag so the paper bag it comes in doesn't get torn in the freezer. I usually only freeze it when I get it on sale cheap (like this time of year!) and have an extra bag or two. The cake mixes I put the whole box in, I'd think you could do the same w/ the Jiffy mixes. Sugar I would not put into the freezer--it's going to draw moisture and become a giant sugar cube!

Someone told me a long time ago that if you freeze flour it will kill the bug eggs that are in it, so if you don't use it right away it will not get bugs in it once it's been frozen. She said flour naturally has those eggs in it, that's why we often get bugs in flour and mixes that contain flour. I have no idea if that is true or not!

I store our flour and sugar in the freezer. Our containers will not hold the 4-5# bags, so the remainder stays in the freezer. I haven't had a problem with white sugar becoming a sugar cube, but the brown will become a hard lump. I also store pasta and dried beans in the freezer whenever there's not room in the canister for them. We have had mice get into these items before.

Thank you all for the responses. I have frozen our all purpose flour in a gallon bag. I actually ended up throwing away our Jiffy Mix because I remembered we had bought it a year ago. But I know I can freeze it if we ever do buy it again :-)