When I first saw an unopened bag of dried-out pet food tucked away in the back of my pantry after months of being there, I really did not think twice about it. However, I did hate the fact that I would just throw it out.
As we all know, peels from fruits and veggies, coffee grounds, etc., can easily be tossed into our compost bins. But pet food? That seemed to be a completely different ball game.
After doing some research on pet food and composting, I discovered that while it can be composted, it does need to be done a little more carefully than regular kitchen scraps. This is important because of its unique ingredient makeup. Also, it matters how those ingredients break down. Furthermore, pet food can pose a couple of additional concerns.
Are Pet Foods Technically Compostable?
As mentioned earlier, the majority of pet foods are made using organic ingredients. Organic means they will eventually decompose. With varying degrees of success depending upon the specific formulation and types of ingredients present, proteins and fats in pet foods can be broken down by the very same microorganisms that break down regular food scraps.
However, because of their high protein and fat content, pet foods behave somewhat differently than other organic materials that can be put into a compost bin. For example, in addition to potentially causing pest problems, pet food can cause an imbalance in the microbial activity in a compost pile. This happens if not handled correctly.
If you’re anything like me, this is often when people are caught off guard. Something might be theoretically capable of being composted, but in practice, it can be quite challenging.
Do You Really Want to Put Your Expired Pet Food Into Compost?
Yes, you can add old pet food to your compost pile, but do it with caution. Most professional composters recognize that pet food is made from organic matter; therefore, it is technically capable of being composted. However, whether or not it is successful will depend entirely on the type of composting method you plan to employ.
The Best Option: Hot Composting
Generally speaking, hot composting is the best method for composting pet food. This is because the heat generated by a well-maintained composting environment helps speed up the decomposition process of organic materials. In addition, it significantly reduces the likelihood of bad odors developing. Larger compost piles that are regularly maintained are typically able to efficiently manage small amounts of pet food. They do this far better than smaller, neglected piles.
Why Smaller Yard Composts May Struggle
While yard-sized compost piles have difficulty processing animal-based materials due to their tendency to attract a variety of unwanted critters, including rodents, raccoons, stray cats, dogs, and various insects, large amounts of pet food added too quickly can lead to an unpleasant smell issue. Therefore, it is important to add such food slowly.
One thing I learned early on with yard composting is that adding any amount of problematic materials before establishing sufficient microbial activity within the compost bin will only increase the workload associated with maintaining the compost bin.
Pet food clearly falls into this category.
Composting Old Pet Food Risks
Pet Food Could Draw Pests
Organic animal products tend to be particularly appealing to a wide range of wildlife and scavenger animals. Even dried-out pet food can attract unwanted attention if left on the surface of a compost pile long enough. As a result, animals commonly attracted to pet food include rats, mice, raccoons, flies, and numerous other insect species searching for a quick meal.
Unpleasant Odors May Develop
Because proteins and fats break down differently than most plant materials, excessive amounts of pet food may result in unpleasant odors emanating from a poorly ventilated compost bin. Furthermore, poor air circulation combined with excess water can worsen odor development.
Using smaller amounts of pet food can limit the onset of both pest attraction and unpleasant odors.
Moldy Pet Food Requires Additional Precautions
Older expired pet foods often exhibit signs of mold growth, especially if they were stored in a humid environment. Certain types of mold may pose harm to humans and animals. When handling moldy pet food, please exercise extreme caution by avoiding inhalation of the resulting dust and spores. Also, consult your local authorities regarding safe methods for disposing of moldy pet food.
Let me tell you, if the pet food appears to be severely damaged, moldy, or otherwise questionable, err on the side of caution and treat it as hazardous waste instead of risking having it negatively affect your composting efforts.
Composting Old Pet Food Safely
Keep Quantities Low
As discussed previously, one key rule of thumb when adding old pet food to your compost bin is to keep the amounts low. Importantly, adding small amounts at a time allows microbes in the composting system adequate opportunity to begin breaking down the organic materials. This happens without becoming overwhelmed.
Place Pet Food Far Beneath Surface Layers of the Compost Bin
Regardless of how you choose to add old pet food to your compost bin (e.g., shreds, chunks, etc.), always bury it deeply beneath layers of other organic materials. Preferably, use carbon-rich materials such as shredded newspaper, cardboard, dry straw, burlap, or similar materials. These serve as excellent carbon-rich browns.
By covering your pet food and reducing visibility and odor from predators and wildlife, you’ll greatly decrease the pest-attracting properties associated with old pet food.
Achieve a Balanced Mix of Greens and Browns
An ideal compost bin maintains a balanced ratio of nitrogen-rich “green” organic wastes (food) and carbon-rich “brown” organic wastes (paper and cardboard). Since pet foods act primarily as nitrogen-rich organic waste additions, they must be adequately supplemented with an abundance of carbon-rich browns. This is necessary in order to maintain optimal biological activity within the composting process.
Active mixing and composting provide oxygen for microorganisms to thrive and assist in achieving proper moisture levels necessary for the breakdown of organic materials. An ideal compost bin should remain moist throughout the decomposition process. However, it should never be excessively soggy.
Consider Utilizing Local Commercial or Municipal Composting Programs
Although home composting offers an environmentally friendly alternative to landfills for countless forms of household organic waste, unfortunately, certain items, such as spoiled pet foods, may prove extremely difficult (if not impossible) to manage safely via home composting systems.
Fortunately, many urban municipalities offer industrial-scale (larger-than-home) commercial municipal organic waste recycling services that are specifically equipped to accept difficult-to-compost materials such as spoiled pet food waste. Therefore, before making any decisions on how best to manage your expired pet food waste, I recommend researching options offered through local waste management organizations in your area.
When Is Disposal Better Than Home Composting for Old Pet Food?
There are times when it’s simply safer and easier to dispose of spoiled pet foods rather than attempting to recycle them through home composting practices. Examples of situations that warrant disposal include:
You Have a Weak or Dead Compost System
Adding spoiled pet food to a dead or slow-moving compost pile is essentially asking for trouble. Once established, pest infestations and foul-smelling odors are almost guaranteed. If your home compost system is experiencing performance-related difficulties (dead, unhealthy, or inactive), then adding spoiled pet food could accelerate these problems.
Large Quantities of Spoiled Pet Food Are Present
Spoiled pet food waste can easily become overwhelming even for larger, well-established backyard home compost systems. Apartment dwellings with limited space, or households utilizing worm compost bins, are not suited to accommodate animal-derived waste products.
For both scenarios outlined above, municipal organic waste recycling services or recommendations provided by local waste management agencies may represent safer alternatives to attempting backyard home composting.
