Composting is the natural process of recycling organic matter into a nutrient-rich soil amendment. Most people avoid adding meat and dairy scraps to home piles, leading to this food waste being sent to landfills. While these materials cannot be handled by a typical backyard heap, specialized methods and careful management make it possible to safely process nearly all food waste. Controlled techniques successfully divert proteins and fats from the trash and convert them into valuable compost.
Why Meat and Dairy Require Special Handling
The primary challenges posed by meat and dairy are rooted in their chemical composition and the public health risks they present. Unlike plant matter, animal products are extremely high in protein and fat, which slows the aerobic decomposition process. These dense materials often result in an unfavorable carbon-to-nitrogen ratio, sometimes as low as 5-to-1, far below the ideal 20-to-1 to 30-to-1 range required for efficient composting.
When decomposition slows and oxygen becomes depleted, the process shifts from aerobic to anaerobic, leading to the production of foul-smelling compounds like hydrogen sulfide and putrescine. Meat and dairy can also harbor dangerous human pathogens, including Salmonella and E. coli. If a compost pile does not achieve sufficiently high temperatures, these bacteria can survive and potentially contaminate garden soil and food crops.
The Bokashi Method
The Bokashi system offers a two-step, controlled solution that handles all food scraps, including meat, bones, and dairy. This method is technically a fermentation process, not traditional composting, and must take place in an airtight container to maintain an anaerobic environment. The process uses specialized bran inoculated with effective microorganisms, such as lactic acid bacteria and yeasts, to effectively “pickle” the food waste.
To begin, layer your food scraps with a handful of the inoculated bran, pressing the material down firmly to remove trapped air. Once the container is full, it is sealed and left to ferment for 10 to 14 days, during which the microbes break down the material. The resulting product is not finished compost but a highly acidic, fermented biomass that can then be safely buried or incorporated into a traditional compost pile. This initial fermentation step eliminates the odors and pest attraction risks associated with raw meat and dairy before final decomposition begins.
Alternative Safe Decomposition Methods
For those who prefer not to use a specialized fermentation system, deep trench composting provides a simple, low-tech alternative. This method involves burying the food scraps directly into the garden soil, utilizing the earth as the composting container and pest barrier. To safely process meat and dairy, you must dig a trench or hole that is at least 12 to 18 inches deep.
The food waste is placed into the trench and immediately covered with the excavated soil, ensuring a thick layer of earth separates the scraps from the surface. This burial depth effectively prevents flies and rodents from accessing the high-protein material, while natural soil microbes slowly break down the waste. This approach is best suited for small, intermittent batches of scraps and should be done in areas of the garden that will not be planted for at least a month.
Commercial Facilities
For larger volumes of waste, such as from restaurants or municipalities, the most reliable and efficient method is through specialized commercial composting facilities. These industrial operations are designed to process high-risk materials, utilizing large-scale machinery to ensure the necessary high temperatures and consistent turning are achieved for guaranteed pathogen destruction.
Managing Heat, Pathogens, and Pests
Regardless of the method used, managing heat and deterring pests are paramount to safe composting of animal products. The thermal management of an aerobic pile is the most reliable way to sanitize the finished product. To eliminate harmful pathogens like Salmonella, the internal temperature of the compost mass must reach a minimum of 131°F (55°C) and be maintained at or above this level for at least three consecutive days.
This high-heat phase, known as the thermophilic stage, requires a large, well-balanced pile and frequent turning to ensure all material cycles through the hottest core. A long-stemmed compost thermometer is necessary to accurately monitor the temperature and confirm sanitization has occurred. Preventing pests involves using a physical barrier, such as a sealed Bokashi bucket, a secured tumbler, or the required 12 to 18 inches of soil cover in trenching. After the active decomposition phase is complete, the material must undergo a final curing period to stabilize the nutrients before being used on edible gardens.