Not Banana Peels: The Carb-Filled Kitchen Scrap Your Compost Will Love

It's easy to forget how quickly some pantry staples go bad in the back of your cabinet or fridge, and you probably toss them without thinking twice. While most people know that fruits, vegetables, and even coffee grounds are compostable, did you know that some carb-heavy kitchen staples are also compost-friendly? Not only can you toss moldy bread in your compost pile, but you can also add moldy tortillas to the mix. Tortillas, just like most types of bread, are primarily made of flour, water, and salt. This classifies them as "green matter" — nitrogen-rich substances that boost microorganism growth, making them an incredibly helpful addition to compost.

So next time you say goodbye to pantry clutter, add those stale tortillas into the compost pile, too. And if you notice that soft, fuzzy spots have already started to grow, that's fine still, as mold is a type of fungus that can actually help accelerate the breakdown process of compost matter. That said, moldy bread like tortillas should not be added to worm bins, and if you do, do so only after you've tested to see how the worms will react. As the Public Works of LA County notes, "The molds that form on most vegetables are usually OK, but the molds on some fruit and bread can be problematic [to a worm's digestive system]."

We have to remember that compost piles are rather sensitive, so make sure not to include any non-compostable materials, such as plastics or wrapping papers. Don't get all excited and toss the whole tortilla down the compost bin, either — tear them into small pieces first. And if your moldy tortillas include anything with meat, dairy, or oils (think of a moldy, meaty quesadilla), it's best to keep it away from the compost bin altogether. Generally, animal-based products are some of the things you should never add to a compost heap. It can attract animals, as well as spread E. coli and Salmonella, which are some of the harmful bacteria that can put your compost ecosystem at risk.

As for the moldy tortillas that make it to your compost, breaking them into smaller bits helps distribute the mold and nitrogen from this particular green matter evenly throughout the heap. Moreover, to avoid any pests or scavengers from entering your compost bin, make sure to place the tortillas somewhere in the middle of your pile. 

As mentioned earlier, moldy tortillas count as "green matter", so you'll need to mix them in with an equal portion of "brown matter", which are carbon-rich materials like papers and leaves. Lastly, be sure that your compost contains the right amount of moisture (~40% to 60%), which is necessary for the organic material to break down, as well as allow for the microorganisms present in the compost heap to thrive properly.