Can I Put Moldy Food in My Compost or Worm Bin?

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Moldy Food In Compost

Compost and worm bins are popular methods for getting rid of waste. These types of bins ultimately create compost, which is organic material that can help plants grow. Repurposing waste in order to help our plants grow is a win-win, don’t you think?

You may be wondering: Can I put moldy food in my compost or worm bin? Yes, you can! The composting process requires composition, so when you add moldy foods, you’re just adding in foods that are already decomposing. Worm and compost bins can have both moldy foods and fresh foods added and you will end up with great compost either way!

In this article, we are going to provide the tools necessary to make you, the reader, an expert on composting, worm bins, and items that can and cannot be added to them. We will also walk you through which moldy foods can be put into compost or worm bins, and the reasons why and why not.

Putting Moldy Food in Your Compost or Worm Bin

Before getting to the hows and whys of what items can and cannot be placed in compost or worm bins (especially moldy food), let’s take a look at a brief description of compost bins and worm bins, why they are useful and why they are beneficial.

What are Compost Bins and Worm Bins?

Composting, at its core, is the process of allowing organic material to decompose. So, a compost bin is the container in which organic material decomposes. Many people choose to have compost bins at home, either indoors, outdoors or both.

Finished Compost Bin

Worm composting is a form of composting in which worms are used to recycle and decompose organic material. In worm composting, food sources and other organic materials are fed to worms. The materials compost as they pass through and exit the worms.

Worm bins, like compost bins, are the containers in which worm composting takes place. People also choose to have worm bins at home, indoors, outdoors or both.

Worm Bin

Seems simple enough, right? Truly, it is, but there are some things to know about composting and worm composting that are important to make the process successful.

The Uses and Benefits of Composting

Composting has many great uses and benefits, not only just for plants and gardens, but for us humans too. Texas A&M states that if we composted most of our kitchen and food waste, we could divert 20 to 30 percent of the trash and waste that goes to landfills. We could put that waste to use, too!

Composting has other uses and benefits, such as:

  • Providing nutrients to plants and gardens
  • Improving the physical characteristics of soil
  • Improving the aeration of soil
  • Improving soil’s capacity to hold nutrients and water
  • Effectively and naturally getting rid of our waste and scraps

But ask the animals, and they will teach you, or the birds in the sky, and they will tell you; or speak to the earth, and it will teach you, or let the fish in the sea inform you. Which of all these does not know that the hand of the Lord has done this? In his hand is the life of every creature and the breath of all mankind.

Job 12:7-10

What You Can and Cannot Put in Your Compost Bin and Worm Bin

We already let you know that, yes, you can put moldy food in a compost bin. A few more instructions and guidelines are important to see more than just a simple yes, though, and we will go through that shortly. First, let’s look at some of the main things that can be put in a compost bin and worm bin.

Quite a few more things can be added to compost bins than worm bins, just because in worm bins, the health of the worms needs to be taken into consideration. Keep that in mind as we go along.

What Can Be Put in a Compost Bin

  • Eggshells
  • Grass clippings
  • Fruits and vegetables
  • Coffee grounds
  • Coffee filters
  • Tea bags
  • Shredded newspapers
  • Nut shells
  • Yard trimmings
  • Houseplants
  • Hay
  • Straw
  • Cardboard
  • Wood chips
  • Leaves
  • Hair and fur
  • Wood ashes
  • Dryer lint
  • Vacuum cleaner lint
  • Sawdust

What Cannot Be Put in a Compost Bin

  • Coal or charcoal ash
  • Dairy products
  • Plants with diseases or bad pests
  • Pet feces and other feces
  • Fat, grease, lard and other oils
  • Yard trimmings that have been treated with chemical pesticides
  • Meat or fish bones and scraps

What Can be Put in a Worm Bin

  • Fruit and vegetable scraps and peels
  • Eggshells (pulverized)
  • Tea bags (staples removed)
  • Coffee grounds
  • Coffee filters
  • Plain cereal
  • Plain bread (okay if a small amount of mold is on it)
  • Plain pasta
  • Dryer lint of natural fabrics only (cotton or wool)
  • Shredded leaves
  • Shredded paper/newspaper
  • Cardboard

What Cannot Be Put in a Worm Bin

  • Meat, fish or poultry
  • Oils like mayonnaise, butter, and salad dressing
  • Dairy products
  • Highly spicy foods
  • Highly acidic foods
  • Pet feces or other feces

Putting Moldy Food in Compost Bins or Worm Bins

Now that you know more about compost bins and worm bins and what can and cannot be put in them, we can get to the root of the matter: putting moldy food in them. Let’s go over adding moldy food to each of the bins.

Moldy Food in Compost Bins

If you want to put moldy food in your compost bin, that’s great! As we previously stated, compost is a means of decomposing organic material, and when food is moldy, that technically means the food is just on its way to decomposing.

If you are going to put moldy food in your compost bin, first make sure that it’s a type of food that can be added to your compost bin. For example, you are not supposed to add dairy products to your compost bin, so if you have moldy cheese – you cannot put that in your compost bin.

On the other hand, if you have a moldy fruit or vegetable peel or some other moldy acceptable food, it can go in the compost bin. It is important to know the process to follow when adding moldy food to a compost bin, which we will discuss shortly.

Moldy Food in Worm Bins

When it comes to putting moldy food in worm bins, it needs to be done the correct way, and only with moldy fruits or vegetables. Anything else has the potential to create more mold and mold spores inside the worm bin, which affects not only the worms, but it can affect you too. Moldy food, if applied in the wrong way, can also attract unwanted pests in your worm bin such as fruit flies and other fly larvae.

Certain molds can be toxic to the worms in the worm bin, which can cause them to be sick and die. No one wants that! Feed moldy fruits or vegetables to your worms responsibly and sparingly.

If you have put some moldy food in your worm bin, then be sure to keep an eye on your worm bin to make sure more mold is not developing inside it.

How to Properly Add Moldy Food to Your Compost Bin

As mentioned previously, certain steps are recommended for adding moldy food to your compost bin. These steps help decomposition happen, while also helping to avoid bad smells and pests. Let’s go through the steps for properly adding moldy food to your compost bin.

Step One: Blend the Moldy Food in a Food Processor

Blended Kitchen Scraps

While this step is not required, it does have many benefits. I like to collect our food scraps in plastic bins under the sink. Once they are full, I then use a food processor or blender to pulverize the food scraps into a mush. Most of the time this food has begun to grow some mold, which is perfectly fine!

Blending the food scraps allows the worms or microorganisms in your compost to digest the food faster. This means less time to grow more mold while in your bin and less time to attract unwanted animals and insects.

Pro tip: This is a great time to add crushed eggshells and coffee grounds into the blended mix. If going into a worm bin, the eggshells provide grit that helps the worms digest the food.

Step Two: Add the Moldy Food to the Center of Your Compost Pile

It is not recommended to add moldy food to the compost pile just anywhere. Add moldy foods to the center of the compost pile and on top of brown, dried material like hay, leaves or grass clippings.

This is useful because the center of the pile heats up more quickly, meaning your moldy food will decompose more quickly.

If adding to a worm bin, I always like to rotate the place where I add the food. This makes the worms travel more around the bin to digest as much of the material as possible.

Step Three: Cover the Moldy Food

Cover the moldy food as soon as it is added to the pile. Do this with more of the dried, brown material like shredded paper, yard trimmings, grass clippings or leaves.

Step Four: Add Aged Manure or Garden Soil

Adding aged manure or garden soil to the top of the moldy food you have added will help it decompose more quickly. (This step is only recommended for compost bins and not for worm bins.)

Step Four: Turn the Compost Repeat if Necessary

Turn your compost pile frequently to aerate it, keep it from smelling bad and speed up decomposition. If you add more moldy food to the top and center of your compost pile, repeat these steps as necessary.

We have written a full detailed article on turning compost and you can check that out here – When Should I Turn My Compost Pile?

If pests or animals are disturbing the compost pile or bin since you have added the foods to it, make sure not to add any more and consider changing how you are containing your compost pile.

You can check out our Best Compost Products page to help you get started with composting!

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Corey Leichty

Hi, I’m Corey and I love using gardening as a way to provide food for my family, learn life lessons alongside my wife, Andrea, and teach life lessons to my two sons. Do you have gardening questions? Not finding what you are looking for? Please feel free to Ask a Question (Click Here!) and I will get back with you as soon as I can!

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