I thought dry food goes off when exposed to air, like wet food only more slowly, and I thought it was best to throw it away if it stays uneaten for a while, not top it off occasionally.

In order for bacteria to multiply effectively, it needs a source of food and high moisture. Anything over 10% moisture will grow mold and bacteria. Bacteria thrive at moisture levels above 20%. We manufacture all of our own products and we dry our foods to a moisture content of 3-5%. At this level mold and bacteria will not grow and multiply. Wet food typically has a moisture content 72 – 84%. At this level of moisture bacteria immediately begins to multiply. In the right conditions, most bacteria double their populations every 20 minutes. This is why it is recommended that wet food not be left out for more than 3 hours. Dry food on the other hand will not grow mold or bacteria unless you add water. The saliva that a cat may impart to the food in the bowl is usually not enough to allow bacteria to grow.

Oxygen is the enemy of all types of food. Oxygen will interact with food dry or wet and cause free radicals to form which in turn will cause rancidity. We add natural antioxidants to our food to prevent this process, but the food can only be protected for so long. This is why we recommend that once the bag of food has been opened that you use it within 6 months. Because the food is generally stored in an air tight foil bag and the extra air can be burped out of the bag, the food will stay fresh for 6 months.

Once the food is placed in the cat dish there is an abundance of oxygen circulating around the dish. This is where our antioxidants get a strenuous work out and shelf life is dramatically reduced. In an open air environment, the antioxidants will protect the food for about 14 days, however, we recommend that you never allow the food to remain in the dish for more than seven days.

Rancidity is a very complex process that your cats are extremely sensitive to. There are certain volatiles that are given off by the rancidity process which your cat can detect long before you can. Your cat will drastically reduce the amount of food they eat or stop eating the food entirely if the rancidity process is occurring in their food. They will generally stop eating the food long before it would even become dangerous for them to continue eating the food.