Can You Compost Dairy: An In-Depth Examination

  • By: Sam Richards
  • Date: July 25, 2023
  • Time to read: 8 min.

The green revolution has taken root in many people’s lives, and an important aspect of this movement is composting — a natural, low-cost method to transform organic waste into nutrient-rich soil. Composting not only keeps kitchen scraps and yard waste out of landfills but also enriches garden soil, boosting the growth of plants and reducing the need for chemical fertilizers. It represents a small but significant step towards a more sustainable lifestyle.

Yet, when it comes to composting dairy products, a sense of ambiguity and uncertainty often ensues. Dairy, while undoubtedly a common part of our daily consumption, has a somewhat controversial status in the realm of composting. Some gardeners are hesitant to include it in their compost bins due to a variety of perceived risks and complications.

Is composting dairy possible or even advisable? If yes, how can it be done safely and effectively? And if not, what alternatives exist for managing dairy waste? To answer these questions, we need to peel back the layers of this complex issue, exploring what exactly dairy is, its impact on compost, and the potential problems and solutions associated with composting dairy. This article aims to illuminate the intricacies of composting dairy, providing a comprehensive guide for those who seek to make their waste management practices as eco-friendly as possible.

What Is Dairy and Its Impact on Compost

At first glance, the term ‘dairy’ may seem quite self-explanatory — it’s a general term encompassing a range of products derived from the milk of mammals, most commonly cows. This category includes a myriad of products we use daily: milk, cheese, yogurt, butter, and cream, to name a few.

Although we know that these products are edible and offer a variety of nutritional benefits to humans, their role in composting is less straightforward. The primary reason behind this complexity is the nutrient content of dairy products and the way they break down during composting.

Dairy products are known to be rich in protein — a compound that primarily consists of nitrogen. In the world of composting, nitrogenous materials are classified as ‘greens’. These are the dynamic components that fuel the composting process by feeding the microorganisms that break down organic material.

However, dairy doesn’t behave like other ‘greens’ such as vegetable scraps or grass clippings when added to a compost pile. As dairy products decompose, they undergo unique changes that can cause disruption in the composting process. The reasons for these challenges are largely due to their high protein content and moisture-holding capacity, which can create a denser, slower-decomposing mass that can offset the balance of the compost pile.

Furthermore, the decomposition of dairy can influence the microbial balance of the compost pile. While beneficial bacteria are necessary for the composting process, the decomposition of dairy can encourage the growth of less desirable microorganisms, potentially leading to a host of issues.

Thus, understanding the behavior of dairy in a compost pile is crucial in discerning its potential impact and the measures necessary to compost it safely and effectively.

Potential Problems with Composting Dairy

One of the main problems with composting dairy is the unpleasant odor it can produce. As dairy products decompose, they can create a stinky smell that is far from the earthy aroma associated with a healthy compost pile. This odor can be disruptive to your household and may even irritate your neighbors.

Additionally, dairy products can attract pests. Rats, raccoons, flies, and other unwanted critters might be lured to your compost pile if it contains decomposing dairy.

Finally, dairy products can contribute to the growth of harmful bacteria or pathogens. Although a well-maintained compost pile can generate enough heat to kill most harmful organisms, not all compost piles reach these necessary temperatures.

When Can Dairy Be Composted

While it’s clear that composting dairy presents a unique set of challenges, it’s important to know that it isn’t an impossible task. In fact, there are certain circumstances and methods under which dairy can be composted effectively and safely.

Large-scale, commercial composting operations often handle dairy products without a hitch. These facilities have the infrastructure, expertise, and equipment to manage dairy composting effectively. Their methods involve composting at high temperatures, typically over 140 degrees Fahrenheit, for sustained periods. Such high heat effectively neutralizes the potential issues associated with dairy composting, including the elimination of harmful pathogens.

On a smaller scale, like a household compost system, there are methods that can safely include dairy. One such method is Bokashi composting, an ancient Japanese composting technique. This method involves fermenting kitchen waste, including dairy, in a sealed container using a special Bokashi bran inoculated with effective microorganisms. The fermentation process prevents the rotting and foul odors usually associated with dairy decomposition, and the end product can be mixed with garden soil or compost to enrich it further.

Another technique is hot composting, a method that, when executed correctly, can reach high temperatures capable of composting dairy safely. This method requires careful control of the compost ingredients, ensuring an optimal balance of ‘greens’ (nitrogen-rich materials) and ‘browns’ (carbon-rich materials), along with frequent turning of the compost pile to maintain oxygen levels and distribute heat evenly. It’s a bit more labor-intensive than other methods but can yield great results.

Despite the challenges associated with dairy composting, understanding when and how dairy can be composted opens up possibilities to include these commonly discarded items in our composting efforts, moving us closer to a zero-waste lifestyle.

How to Compost Dairy Safely at Home

While dairy products can pose a challenge in a conventional compost pile, they can indeed be composted at home when handled correctly. The Bokashi and hot composting methods have proven effective for this purpose. Here’s a step-by-step guide for each method:

Bokashi Composting:

  1. Collect Your Bokashi Supplies: To start Bokashi composting, you’ll need a Bokashi compost bin and Bokashi bran, which is a mixture of wheat bran and effective microorganisms that facilitate the fermentation process.
  2. Add Your Kitchen Scraps: Begin by adding your kitchen waste to the bin, including dairy products. Cut large pieces into smaller ones to speed up the process.
  3. Sprinkle Bokashi Bran: After each layer of waste, sprinkle a handful of Bokashi bran over the top. This bran helps to ferment the waste, breaking it down without producing a bad smell.
  4. Press Down and Seal: It’s important to compress the waste to remove air pockets and seal the bin tightly after each addition. Oxygen can interrupt the anaerobic fermentation process.
  5. Drain Liquid: Bokashi bins have a tap that allows you to drain off the liquid produced during fermentation. This should be done every few days.
  6. Wait: Once your bin is full, seal it tightly and let it sit for two weeks to allow the fermentation process to complete.
  7. Use Your Compost: After two weeks, the contents of your bin can be buried in the garden soil or added to a traditional compost pile to finish breaking down.

Hot Composting:

  1. Prepare Your Compost Site: Choose an appropriate location for your compost pile/bin. It should be easily accessible and ideally, not directly on a wooden deck or other surface that could be damaged.
  2. Gather Your Compost Materials: Collect a mix of ‘greens’ and ‘browns’ for your compost pile. Dairy products, as a source of nitrogen, are considered ‘greens’, but should be used sparingly. You’ll need a larger amount of ‘browns’ to maintain balance.
  3. Layer Your Materials: Start with a layer of ‘browns’, then add a smaller layer of ‘greens’, including your dairy products. Follow with another layer of ‘browns’.
  4. Turn Your Compost Regularly: Turning your compost pile frequently is key in hot composting. This allows for aeration, distributes heat evenly, and helps the pile reach high temperatures.
  5. Monitor Temperature: Hot composting requires heat. Using a compost thermometer, check to ensure your pile is reaching at least 140°F. This temperature helps to break down dairy products and kill potential pathogens.
  6. Wait and Use: Once your compost pile has cooled down and turned into a crumbly, dark material with an earthy smell, it’s ready to be used in your garden.

By following these steps, composting dairy at home can be achieved safely and effectively. It not only helps in reducing waste but also enriches your garden soil with nutrients.

Considerations and Alternatives for Dairy Waste

While composting dairy at home is a feasible option, it’s also essential to consider the broader spectrum of waste management strategies, particularly concerning waste reduction and alternative uses for dairy waste.

The first line of action in waste management should always be a reduction at the source. With respect to dairy, this translates into mindful consumption practices. This could involve planning meals to ensure dairy products are used before they spoil, buying only as much dairy as necessary, and selecting products with less packaging to minimize waste.

While we strive to reduce waste, it’s inevitable that some dairy waste will still be generated. If you find composting dairy at home challenging, there are other potential outlets for these products:

  1. Animal Feed: Depending on the type of dairy waste and local wildlife, some can be safely fed to animals. Household pets like dogs can consume certain types of dairy, and some local farms or wildlife centers may also accept food scraps for feeding animals. It’s important to research and ensure that the type of dairy waste is safe for the animals to consume before proceeding.
  2. Commercial Composting Facilities: In some areas, commercial composting facilities accept dairy products and other typically non-compostable items. These facilities have industrial-scale composting systems that can handle materials that home composting systems can’t.
  3. Worm Composting (Vermiculture): Certain dairy products, such as yogurt and cheese, can be composted in small amounts in worm bins. Worms are quite sensitive to changes in their environment, so it’s crucial to add only small amounts and observe the worms’ reactions.
  4. Community Collection Programs: Some municipalities offer food waste collection programs. They collect and compost food waste, including dairy, at a municipal facility.

Exploring these alternatives can help us manage dairy waste responsibly when home composting isn’t an option. As with any aspect of sustainability, the key is staying informed, making mindful decisions, and adapting to practices that align with our individual capacities and local contexts.


Composting is a compelling means of transforming organic waste into valuable resources, contributing to both our personal gardens and the overall health of the planet. It encourages us to examine the waste we generate and to rethink how it can be reused or recycled. Dairy, being a prevalent part of many of our diets, is a considerable component of this conversation.

Understanding the intricacies of composting dairy products is crucial for effective waste management. While composting dairy at home might pose some challenges due to the unique properties of these products, it’s clear that with the right methods such as Bokashi and hot composting, dairy can be safely composted at home. Additionally, there are numerous alternatives for managing dairy waste, from commercial composting facilities to animal feeding, if home composting isn’t suitable or available.

Ultimately, the conversation around composting dairy underlines the broader need for waste reduction and mindful consumption. Embracing strategies that minimize waste, coupled with effective management of inevitable waste, paves the way toward a sustainable, zero-waste lifestyle. We all have a role to play in this endeavor, and understanding the details of dairy composting is a valuable addition to our toolkit in navigating the path to sustainability.

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