Every bag of our food has an expiration date. Beyond this date, we do not recommend using the food. Once you open the bag it is best to use it within 4 months even if the expiration date is further out.
Each bag of food we manufacture is nitrogen flushed to remove most of the oxygen from the bag. Oxygen is the main reason why a food goes rancid or spoils. Once you open the bag, you are letting oxygen back in to react with the fats in the food. We use natural preservatives in our foods, but they can only protect the food for so long. It's hard to know when a food has spoiled, but cats are very sensitive to rancidity and can detect it long before you can.
Three conditions contribute to rancidity; light, temperature and oxygen. Oxygen can diffuse right through the standard plastic zipper bag, so freezing the food does not slow the rancidity process down. You will need an oxygen barrier bag similar to what is used in home vacuum sealers. If you are going to freeze our food, a chest freezer is best. Frost-free freezers stay frost free by warming from zero degrees Fahrenheit to approximately thirty-two degrees Fahrenheit one to four times daily. This causes moisture in the food to propagate from the warm side of the bag to the cold side of the bag forming a block of ice on the cold side of the bag.
People will often transfer our food to a pet food container. If the container is not cleaned thoroughly between fillings, the oils from the previous food can cause the new food to go rancid. If you transfer the food to a pet food container, be sure to thoroughly scrub the entire container (lids, seals and gaskets) with soap and a scrub brush then allow it to completely dry. Fats can become hard and be difficult to remove without scrubbing. You can also use the pet food bag or a disposable liner in the pet food container.
There really is no convenient way to store large amounts of pet food. Our best recommendation is to buy a six month supply of food at a time and store in a cool, dark, dry place. Follow these simple rules and your pet will always enjoy fresh, wholesome food.