Most dogs and cats eat dry food. That your pet doesn't eat "fresh" food, doesn't mean that you don't need to be careful on how you store it.
First thing you must check is the expiration date. Pay attention when you buy the food, but also use some common sense. If food smells bad, or different from before, or if your dog or cat doesn't want to eat it, it might be spoiled. If that's the case, call Customer Service and let them know.
Storing the dry food properly is important so that it will keep its nutritional values. If dry food is exposed to aire, light, high temperatures (over 38ºC - 100.4F) or too much humidity, it will loose quality. According to dry food brands, it will lose vitamins.
The best way to store dry food it's in its original packaging. One piece of advice: open the bag carefully, so you can later roll it and close it with a clip. Some have already a zip to close the bag.
To protect the food against insects or rodents, you can use a plastic, metal or cristal container. *Don't put the food directly in the container, instead *keep the original packaging. Plastic or metal containers can change the food's taste.
Dry food should not last open more than six weeks, so always buy according to your pet's needs.
If your pet leaves some food in the bowl, don't keep it for more than 24h. If they haven't finished, just throw it away and put some more food.
And remember to wash the bowl at least once a week! You don't want slimy bacteria living in your pet's bowl!