Can Compost Worms Eat Moldy Food?

The worms in your vermicomposting bin might seem down to eat just about whatever you toss in the container. They don’t seem to mind whether you give them shriveled fruits and vegetables or eggshells and coffee grounds. They’ll work through it, creating a nutrient-dense material perfect for your garden. 

However, perhaps you bought a bag of apples before heading out for a trip, thinking you and your family would consume them before leaving. Unfortunately, this wasn’t the case, so you return after a few weeks to find moldy apples hanging out in your fruit bowl. 

You don’t want to waste them, so you decide to add moldy fruit to your compost bin. However, maybe you second guess yourself, wondering if this fruit is safe for your composting worms to consume. Or, perhaps we missed the mark entirely, but you’re still asking yourself the same question: Can compost worms eat moldy food? Let’s find out!

Do Earthworms Eat Mold?

Unlike us humans, the worms in your compost pile are indifferent toward food. They don’t seem to care what you give them, as long as they have a steady diet of food. So, if the food is moldy, they’ll still consume it. 

The worms won’t be any worse for wear after consuming the mold, but they might not eat that food. For the most part, earthworms aren’t bothered by moldy food and will consume it regardless of the extras. However, extremely rotted food might not entice the worms enough for them to consume it. 

The longer food sits and rots, the less value it has to the worms. So, while they could eat the moldy food (and they probably will), there’s a chance they might not consume it. The worms are there to help decompose unwanted food scraps, so if the food is already decomposed, they might not be too interested in it. 

Will Mold Ruin My Compost?

Many folks use composting to repurpose their food waste to benefit their garden soil. If you’re an avid gardener, it might be a regular cycle – grow the fruits or veggies, compost the scraps, add the compost to the plants, repeat. 

The presence of mold might make you question the safety of using compost on your fruit and veggie plants. However, while the mold is disconcerting, it’s a completely normal part of the composting process. 

You’ll find mold on dead organic matter (think your compost pile), which simply signifies complete decomposition. To reap the benefits of compost, you usually want to have it fully decomposed. So, mold isn’t necessarily a bad thing. 

That said, you need to be careful with the mold, as it can sometimes be a hazard. For example, if you’re sensitive to mold spores, make sure you wear a mask while turning the compost to avoid inhaling the spores. 

In addition, the presence of mold in a compost pile with meat and dairy (cheese, milk, etc.)  products could indicate the presence of harmful bacteria. These products may attract animals and pests that could make them sick if they consume the compost (keep the pile safely out of reach of your dog or cat). 

Aside from these factors, though, mold in your compost pile isn’t a bad thing. As long as you continue maintaining your compost pile, the mold shouldn’t become an issue. 

Tips For Maintaining Your Compost Pile

The composting pile requires a few essential components for a successful result. These components generally remain the same whether you have a vermicompost pile or something else. If nothing else, your compost pile needs moisture, air, and organic matter. 

Adequate Moisture

Plenty of moisture is essential to any successful compost pile, but it’s imperative if you have a vermicomposting bin. The worms need water to keep their skin moist to enable breathing. So, unless you want the process to come to a screeching halt, it’s important to keep the pile moist.

That said, you don’t want the pile to be too saturated. A waterlogged compost pile is nearly as bad as a bone-dry pile. If there’s too much water, the extra moisture will force the air out, preventing oxygen from getting into the pile. 

Luckily, it’s easy to test the moisture content in your compost pile. Simply grab a handful of compost from the center and squeeze it in your hand. If the mixture is crumbly and won’t form a ball, the mixture is too dry. 

Or, if water drips out of your hand when you squeeze the compost, the pile is too wet. Your compost pile should feel damp but not soaked. It should feel like a well-wrung sponge – damp but not dripping. 

If the pile is too dry, simply add water until you reach the proper moisture level. Or, if there’s too much water, add dry brown materials, like straw, newspaper, or leaves. You can usually tell that your compost pile is too wet, as it’ll probably smell unpleasant. 

A healthy compost pile shouldn’t smell bad; instead, it should have a pleasant, earthy smell. So, if it stinks, there’s a good chance you added something that you shouldn’t have (meat, dairy products, etc.) or the pile is too wet. 


The organisms hard at work in your compost pile require air to breathe. So, this is an essential part of your composting process. You need to ensure the pile is properly aerated, as a compact pile will decompose extremely slowly. 

Turn the pile regularly with a pitchfork or a shovel, as this will encourage aeration in the pile. You can also encourage air pockets by adding coarse materials, like corn stalks, leaves, straw, or other materials that are high in carbon. 

Avoid adding thick layers of grass or full leaves, as they will create a slimy mat that prevents airflow. So, switch it up by adding different sizes of materials to encourage enough air for the organisms to breathe and thrive. 

Plenty Of Organic Material

To produce compost, you need to collect materials to compost. Without it, you won’t get very far. So, you need to add plenty of organic materials, preferably a variety of them. Generally, you need about a 50/50 mix of browns and greens for healthy and fertile compost

The greens give the microorganisms what they need to grow, while the browns offer plenty of air for the microorganisms to function.