The best way to store pet food is per the manufacturer's recommendations. Check the back of the bag, can, or package to see if your pet's food has any tips for storage.
When purchasing pet food, be sure to inspect the package for rips, holes, or defects that may expose the diet to air.
Dry food is best stored in its original packaging. Kibble bags are specially created to help seal in nutrients while preventing the food from getting damaged or becoming spoiled. Essential nutrients such as fats and vitamins can leach out of the food if it is poured into another container. Storing outside the original bag also exposes the food to bacterial and fungal contamination, increasing the likelihood of rancidity. The original bag provides an extra barrier for pests such as rodents and insects. Storage mites are another important pest which thrive on the high protein and fat content in pet food. They can get in anywhere the food is exposed to air, so keeping the food in its original bag can minimize risk of storage mite contamination. Storage mites can also cause hypersensitivity (allergic) reactions in some pets who are exposed to them.
After opening the bag, squeeze the air out and close it up with a bag clip. Store it off the ground in a cool, dry place, like a pantry or kitchen cabinet. To add an extra layer of protection, you can place the bag in an airtight container. Keep in mind that the scoop you use can have bacteria on it from your hands, so it is important to store the scoop outside of the bag.
Pet food containers and scoops should be washed regularly, at least every time you get a new bag. Wash with hot soapy water, and soak in dilute bleach for extra sanitation.
It is best not to stockpile food, though this may be an attractive choice due to cost savings. To ensure the food stays fresh, only keep enough on hand to last one month. Freezing extra food from an opened bag is a good option for helping it stay fresh if one bag will last more than 30 days.
Canned food should be used within three days of opening. Store unused food in the fridge, inside a sealed container. This could be a reusable plastic or glass container, or you can buy a reusable can cover. Make sure that each time you scoop a new serving of food, you're using a clean spoon to prevent contamination of the can.
Keeping the original packaging is also very important in case there is an issue with the diet. For example, if your pet becomes sick from the diet, you will need the lot or batch number as well as the manufacturer’s information, so you can contact the pet food company. If there is an active pet food recall, you will also need this information to check whether you pet’s food has been affected.
CDC: Pet Food Safety
Dermatology & Allergy Services: Storage Mites
Pet Food Institute: Safe Handling and Storage at Home
Tufts Petfoodology: The Scoop on Storing Pet Food