Composting food scraps like fruits, vegetables, eggshells, and coffee grounds can enrich your garden soil. However, when it comes to dairy products like cheese, yogurt, sour cream, and butter, things get a bit more complicated.
In this comprehensive guide, we cover everything you need to know about composting these diary items to help you make the right choices for your compost pile and garden.
Dairy products like cheese, yogurt, sour cream, and butter can technically be composted. However, they come with a unique set of drawbacks you'll want to consider:
The fat and protein in dairy can attract unwanted pests like raccoons, rats, mice, opossums, and flies. This leads to a disrupted compost pile and could spread bacteria.
As dairy breaks down, it releases unpleasant odors, including the rotten egg smell of sulfur compounds. This causes complaints from neighbors.
Some molds and fungi feed on milk sugars in rotting dairy items. These can transfer to plant roots and lead to diseases.
So while butter and cheeses can decompose, composting them has risks. Weigh these drawbacks against the small benefit diary offers your compost.
If you want to compost dairy items, follow these best practices to reduce issues:
Burying dairy products deep in the center of an established compost pile can prevent odors and discourage pests while still allowing decomposition.
Cutting dairy into smaller pieces gives microbes more surface area to work on, speeding up breakdown so less smells are released.
Mix dairy with brown materials like dried leaves or straw to balance the carbon and nitrogen ratio. This prevents excess ammonia odors.
Turning or stirring the compost pile exposes all parts to oxygen while allowing heat release. This maintains aerobic conditions for safe composting.
Enclosed compost bins with tight-fitting lids prevent access by rats, mice, raccoons, and other unwanted visitors looking for an easy dairy meal.
By carefully managing dairy additions and following these precautions, you can compost moderate amounts of butter, cheese, yogurt, and sour cream with limited issues.
We don't recommend intentionally adding spoiled dairy products like sour milk or moldy yogurt to compost for two reasons:
They contain even more active bacteria that can survive composting temperatures and transfer to plants, animals, or people.
High moisture items like liquid milk don't break down readily and can become anaerobic pockets that generate methane gas and toxic leachate.
While accidentally adding a small amount of spoiled dairy likely won't cause major problems, we suggest disposing of most rotten milk, cheese, yogurt, butter, and sour cream in the trash. The risks outweigh benefits to your compost pile.
Yes, you can compost cheese in small quantities by chopping it finely, burying it deep in the center of the pile, and mixing it with carbon-rich browns. Monitor for odors and pests.
Yogurt contains beneficial microbes but also risks of excess moisture, pests, odor, and contamination when composting. For best results, mix in small amounts with drier materials like straw or leaves.
Sour cream carries high risks of stench, pests, and contamination compared to the small soil benefits. We recommend collecting dairy fat/protein in moderation through other items like eggshells.
Butter and other solid fats technically can break down through composting but may smell bad, leach nutrients, or attract rats. Mix very small amounts with absorbent browns like sawdust or shredded paper.
By understanding what works and what doesn't when trying to compost dairy products, you can enrich your soil safely. Weigh the benefits against the potential drawbacks for your home compost pile. And when in doubt, leave high-fat, high-protein dairy items out of your composter.