Does a compost bin need air holes?

does a compost bin need air holes
The short answer here is YES! The key to successful composting is good airflow. A compost pile without it could literally turn into a stinky mess.

Why do compost bins have holes in them?

As a general rule, the holes in compost bins are designed to allow air to pass through and sometimes to allow drainage.

Using what most gardeners consider “best composting practices” requires aeration since oxygen is a fundamental requirement for aerobic (oxygen-loving) compost microbes. No matter what you do, organic matter will rot. 

There are two ways in which this can occur:

  • Aerobic (with oxygen)
  • Anaerobic (without oxygen)

Any compost container should include openings or slots because aerobic conditions are preferable to anaerobic conditions.

Should compost bins be airtight?

An airtight compost bin will create anaerobic conditions within the bin, which is not considered good practice for efficient composting. Decomposition without oxygen or ventilation results in unpleasant odors and slower results.

Aerobes are the most efficient type of bacteria for composting. These aerobic composting microbes require air to survive. 

In the absence of oxygen, anaerobes take over the process. In an airtight container, these oxygen-hating microorganisms thrive. In these conditions, your organic compost materials are in a state of putrefaction.

Anaerobic decomposition has several disadvantages, including:

  • Composting anaerobically takes about 90% longer.
  • These microbes can hurt plants, which produce useless organic acids and ammonia-type substances
  • Plants get fewer micronutrients from anaerobic microbes than they do from aerobic microbes.
  • Anaerobic decomposition produces hydrogen sulfide, which releases unpleasant smell/smells like rotten eggs.
  • Finally, compost, that’s anaerobic, produces a lot of methane, which is a greenhouse gas.

Even though it is possible to compost your organic waste in an airtight anaerobic environment, this is not always the best option.

What about a compost bin without holes?

To facilitate ventilation and drainage, compost bins require holes and openings. A compost bin with drain holes prevents excess moisture from building up in the bin, reducing efficiency. Airflow is an essential part of the composting process.

If there are no air holes in the bottom of your compost container, you will need to drill plenty of holes so that excess moisture can drain out, unpleasant scents can escape, and oxygen can circulate.

In addition to drilling air holes/drainage holes at the bottom of your compost bin, use a drill bit to drill holes at the sides while you are at it. 

You have likely figured out that those holes serve a purpose by now. To make compost, we need four basic ingredients:

  • Green materials/organic matter (nitrogen-rich), grass clippings, peels, kitchen scraps, veggies, food scraps, coffee grounds, etc.
  • Brown materials (carbon)
  • Water
  • Oxygen

It is challenging to strike the right balance between everything in the right proportions, including moisture level.

It is important to keep in mind that good aeration is more likely to be determined by compost composition.

Include coarse materials such as twigs, scrunched-up paper, or cardboard when building your compost heap. The result will be the creation of air pockets within the mix.

To create good compost, you should occasionally “mix up” your pile. By doing this, any materials that are stuck together are broken apart, and spaces for air to flow are created.

Does a kitchen compost bin need air holes?

Yes, even a kitchen compost bin needs to have an air hole. Air holes are necessary for proper airflow in all types of compost bins. 

For organic materials to break down properly, compost must have an adequate airflow.


Discovering composting as a way of life or even better, as nature’s way of recycling, Ana dedicates her time to trying out new methods of composting at home. Her goal is to share everything that she’s learned in the hopes that it will help others discover the amazing rewards of composting.

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