Compost Smells Like Poop

If your compost smells like poop, you’re not alone. That unpleasant and overpowering odor is a classic sign that something in your pile is out of balance. But don’t worry, a stinky compost bin is a fixable problem. It’s simply your compost’s way of telling you it needs a little help. With a few simple adjustments, you can turn that foul smell into the sweet, earthy aroma of healthy compost.

This smell usually means the composting process has gone anaerobic. That’s a fancy word for saying there’s not enough air. When oxygen is missing, the wrong kind of bacteria take over. These anaerobic microbes produce smelly gases as they break down your scraps. The good news is you can easily get things back on track.

Seeing that heading might make you chuckle, but it’s a serious issue for many gardeners. When your compost smells like poop, it’s more than just a nuisance. It can attract pests, annoy your neighbors, and signal that your valuable compost isn’t breaking down properly. Let’s figure out why this happens and, more importantly, how to stop it for good.

Why Your Compost Smells Bad: The Main Culprits

Understanding the cause is the first step to a cure. A healthy compost pile should smell like fresh soil or a forest floor. If it doesn’t, one of these issues is likely to blame.

Too Many “Greens” (Nitrogen-Rich Materials): This is the most common reason. Greens include food scraps, grass clippings, and coffee grounds. They are wet and nitrogen-rich. If you add to many without enough “browns,” they create a slimy, oxygen-starved mess that reeks.
Not Enough “Browns” (Carbon-Rich Materials): Browns are the dry, carbon-rich materials like dried leaves, straw, cardboard, and paper. They create air pockets and soak up excess moisture. Without them, your greens have nothing to balance them out.
Lack of Oxygen (Anaerobic Conditions): Compost needs air to work. If the pile is too dense, too wet, or never turned, the aerobic (oxygen-loving) bacteria suffocate. The anaerobic bacteria thrive and produce methane and hydrogen sulfide—the gases that smell like rotten eggs or manure.
Excess Moisture: Water is essential, but too much of it fills the air spaces. This creates a soggy, compacted environment where only smelly anaerobic bacteria can live. Think of a wet, sealed bag of grass clippings—it stinks for the same reason.
Poor Drainage or Aeration: If your bin doesn’t allow for air flow at the sides and bottom, or if it sits directly on flat ground without drainage, moisture collects at the bottom. This creates a stagnant, smelly sludge.
Adding the Wrong Items: Meat, dairy, fats, and cooked foods are notorious for causing odors and attracting pests. They break down slowly and create very strong, unpleasant smells in a backyard compost system.

The Quick Fix: How to Rescue a Stinky Compost Pile Today

If your bin is already smelly, don’t just ignore it. Here’s your immediate action plan to neutralize the odor within a day or two.

Stop Adding New Kitchen Scraps: Pause your additions until the smell is under control. Adding more greens will just make the problem worse.
Turn and Fluff the Pile: This is the most important step. Use a pitchfork or compost aerator to turn the entire pile. Move the dry material from the outside to the wet, smelly center. Break up any clumps. You’re literally giving your pile a breath of fresh air.
Add a Generous Amount of Browns: As you turn, mix in lots of dry brown material. Shredded cardboard, straw, or dried leaves are perfect. Aim for a ratio of about 3 parts browns to 1 part smelly greens by volume. The browns will absorb moisture and create space for air.
Check the Moisture Level: Grab a handful of compost from the center. It should feel like a wrung-out sponge—damp, but not dripping. If water streams out, it’s too wet. Add more browns. If it’s dusty, add a little water as you turn.
Cover the Pile: If rain is a problem, cover your bin with a lid or a tarp to prevent it from getting waterlogged again. Just make sure the cover isn’t airtight.

Choosing the Best Browns for the Job

Not all browns are created equal when you need a quick fix. Here’s what works best:

Shredded corrugated cardboard (avoid glossy prints)
Straw or hay (hay may contain seeds)
Dried, crumbled leaves
Sawdust from untreated wood (use sparingly, as it compacts easily)
Shredded paper (newspaper, office paper)

Building Odor-Free Compost From the Start

Prevention is always easier than a cure. Follow these practices to ensure your compost never develops that poop-like smell in the first place.

The Perfect Balance: Greens vs. Browns

Getting the ratio right is the golden rule. A good target is a 2:1 or 3:1 ratio of browns to greens by volume. Don’t stress about measuring perfectly. Just think: for every bucket of kitchen scraps, add two or three buckets of dry leaves or shredded paper.

Greens (Nitrogen): Fruit & vegetable scraps, coffee grounds, fresh grass clippings, plant trimmings, tea bags.
Browns (Carbon): Dried leaves, straw, wood chips, sawdust, paper, cardboard, egg cartons.

Layering and Aeration Techniques

How you build your pile matters just as much as what you put in it.

Start with a coarse base: Begin with a 4-6 inch layer of twigs or straw at the bottom of your bin. This improves airflow from the very beginning.
Use the lasagna method: Add materials in thin, alternating layers. A 2-inch layer of greens, followed by a 4-6 inch layer of browns. This naturally mixes the materials and prevents clumping.
Turn regularly: Turn your pile every 1-2 weeks with a fork. This introduces oxygen, speeds up decomposition, and prevents odors from taking hold. If turning is hard, use an aerator tool to poke deep holes.
Chop or shred larger items: Smaller pieces decompose faster and are less likely to mat together. Chop your food scraps and shred your cardboard before adding them.

Smart Bin Management

Your compost container plays a big role.

Choose a bin with adequate ventilation holes or slats on the sides.
If using a tumbler, give it a few spins every few days to aerate.
Place your bin on soil, not concrete or asphalt, so excess moisture can drain and worms can enter.
Keep a small, sealed container of browns (like shredded paper) next to your indoor kitchen caddy. Add a handful over your food scraps every time you empty it outside.

Common Compost Odors and Their Specific Solutions

While a manure-like smell is common, other odors can point to different issues.

If It Smells Like Rotten Eggs or Sulfur

This indicates a severe lack of oxygen and very anaerobic conditions. The pile is likely too wet and compacted. Turn it immediately and mix in large amounts of coarse, dry browns like straw or small twigs to create air channels.

If It Smells Like Ammonia

An ammonia smell means there is to much nitrogen (greens) and not enough carbon (browns). It’s often seen with large amounts of fresh grass clippings. The solution is simple: turn the pile and mix in a lot of carbon-rich brown material.

If It Smells Sour or Like Vinegar

This can happen with to many acidic materials, like a huge load of citrus peels or tomatoes. While these are okay in moderation, balance them out with browns and consider adding a handful of garden lime or wood ash to neutralize the acidity.

What You Should Never Put in Your Backyard Compost

Avoiding these items will save you a world of smelly trouble.

Meat, Fish, or Bones: They attract rodents and create very strong odors as they rot.
Dairy Products (cheese, butter, yogurt): Similar to meat, they attract pests and smell bad.
Fats, Oils, and Grease: They coat materials, preventing air and water movement, and they smell rancid.
Cooked Foods (especially with oils): Often attract unwanted animals and can create odor issues.
Pet Waste (dog/cat feces): Can contain harmful pathogens and parasites that may not be killed in a backyard pile.
Diseased Plants or Weeds with Seeds: The diseases or seeds might survive and spread to your garden later.

Troubleshooting for Specific Compost Systems

Fixing a Smelly Tumbler

Tumblers can become anaerobic quickly because they are often sealed. If it smells, stop adding greens. Give it a spin daily to aerate. Open the door to let in air, and add a significant amount of shredded cardboard or dry leaves through the door before spinning again. Ensure the drainage holes aren’t clogged.

Fixing a Smelly Worm Bin (Vermicompost)

Worm bins can smell if they are overfed or too wet. Stop feeding for a week. Fluff the bedding to add air. Add more dry, shredded newspaper or cardboard bedding. Make sure the drain tap is open and the bin isn’t sitting in leachate.

FAQ: Your Compost Smell Questions Answered

Q: My compost smells like poop even after I turn it. What now?
A: You may not have added enough browns. Turn it again, but this time, really mix in an abundance of shredded cardboard or straw. The pile should look mostly dry and fluffy, not wet and clumpy. Also, check that your bin itself allows for airflow.

Q: Is it normal for compost to smell a little when it’s new?
A: A new pile might have a slight odor as it starts working, but it shouldn’t be overpowering or foul. If it is, you likely started with to many greens and not enough browns. Add browns immediately.

Q: Can I use lime to stop the smell?
A> Garden lime can help neutralize acidity and reduce odors temporarily, but it doesn’t fix the root cause (lack of air or imbalance). It’s better to fix the structure and balance of the pile first. Lime can also affect the pH of your finished compost.

Q: How often should I turn my compost to prevent smells?
A: For active, hot composting, turning every 3-7 days is ideal. For a slower, cold compost pile, turning it every 2-4 weeks is sufficient to prevent odors. If you smell anything unpleasant, turn it right away.

Q: My compost is wet and smelly but I’m out of browns. What can I use?
A> Look around your home! Shredded junk mail (non-glossy), paper egg cartons, torn-up cereal boxes, or even the lint from your dryer (if from natural fibers) can work in a pinch. Keep a bag of fallen leaves in the fall for use year-round.

Enjoying the Sweet Smell of Success

Dealing with a compost pile that smells like poop is a common hurdle, but it’s one you can easily overcome. Remember, the smell is just feedback. It’s your compost telling you it needs more air, more browns, or less water. By following the steps outlined here—turning your pile, balancing your greens and browns, and managing moisture—you’ll quickly get back on track.

The reward is worth the effort. Instead of a foul odor, you’ll be greeted by the clean, earthy scent of finished compost. This “black gold” will enrich your garden soil, help your plants thrive, and close the loop on your kitchen waste. It’s the ultimate goal of every gardener who composts, and it’s absolutely within your reach.