It depends. If you have a big bag that will last a long time then cold storage will keep it fresh longer. I buy large bags of seed and keep them in the freezer.

I keep about a week's worth of seed at room temperature in a glass jar. The jar makes it easy for me to get the seed and also keeps the bugs out. There are small insects that LOVE to infest bird seed. Freezing the seed will kill them, refrigerating it will make it difficult for them to get into the seed in the first place.

 

I've always heard it is better to freeze. Like Tielfansaid, it keeps the bugs out as well! I bought a bag of seed that was infested with Indian Meal Moth larva.. granted, my bird LOVED the way they tasted, but they ate up the bird seed and left yucky webs everywhere. I thought I got rid of them by freezing the seed (as there were no more in the seed), but a couple months later there were a bunch flying around the house. I killed everyone I saw and I haven't seen any since..lets keep our fingers crossed that they didn't get into my food and breed! lol.

As for freshness, you will want to freeze if you buy in bulk and it won't be used up within a month or two. I freeze my pellets since I buy a 20lb (which is a lot cheaper than buying individual 3lb ones). I'll keep an air tight container with some seed or pellets in it, and have another large container taking up most of my freezer lol.

 

I don't freeze mine, but if I was purchasing more than a couple of pounds at a time I would.