Compost: How To Avoid Bad Smells And Insects?

With the requirement to sort biowaste coming into effect on January 1, 2024, more and more French people will start individual composting. To obtain high-quality compost that can fertilize green plants or vegetable crops, there are mistakes to avoid. We will explain how to prevent bad odors and insects during the composting process.

How to avoid bad smells associated with compost?

Composting is one of the options to comply with the obligation of sorting biowaste that came into effect on January 1, 2024. As an individual, you can install a compost bin at home, in your garden, on your balcony, or even in your kitchen.

When everything goes well, the compost emits a forest floor-like smell. However, be wary of bad odors in case of mistakes on your part! A foul-smelling compost bin is a sign of excess moisture, which prevents the aeration of biowaste and hinders their decomposition process.

To ensure your first attempts at composting aren't foul-smelling, there are certain rules to follow:

- Always put in the bin 50% dry waste (brown and carbon-rich) for 50% wet waste (green and nitrogen-rich). To adhere to this 50/50 rule, you must add an equivalent volume of dry waste with each addition of wet waste.
- Regularly turn the biowaste with a fork to aerate it. Microorganisms need oxygen to transform your waste into compost. If you do not mix everything once a week and with each addition, smells of rotten eggs or ammonia may develop.
- Do not throw proteins such as raw eggs, meat, or fish into the compost. Even though these wastes are indeed biodegradable, they too can emit bad odors.

How to fix compost that is too wet?

To check the proper balance between wet and dry waste in your compost bin, simply grab a handful and squeeze it in your hand. The compost should hold together. If juice leaks out, the mix is too wet.

As mentioned before, it's important to address the issue immediately to prevent bad odors. To correct this, simply add dry waste high in carbon, such as:
• dead leaves collected from the garden.
• straw.
• chipped material from your garden.
• wood cut into small pieces.
• paper.
• cardboard cut into small pieces.

You can also open the bin for a few hours so that the mix is exposed to the sun's heat, or mix your too-wet compost with dry compost or dry soil.

How to keep insects away?

The presence of flies and gnats is another issue that one may encounter when deciding to make compost in their garden.

Here are the right steps to take to keep these unwanted insects away:
• Cover the compost bin if it was open.
• Clean the lid regularly.
• Compost organic waste quickly before it starts to rot, especially in summer and during hot weather.
• Consider adding a layer of chipped wood on top of your additions when you add a rotten fruit or other very moist material.
• Avoid putting meat in the compost as it attracts flies.

Note: While flies and gnats can be problematic, ants and woodlice should not be a concern. They contribute to the composting process and assist bacteria and fungi in their decomposition work.

What are the mistakes to avoid for indoor composting?

It is possible to make your own compost at home even if you do not have a garden or balcony. All you need to do is equip yourself with a worm composting kit sold in garden centers for between €80 and €100, or a sealed bokashi composter.

There are also good practices to adopt to avoid bad smells and insects in the house.

Here are the golden rules to remember:
• Compost your food waste quickly before it starts to ferment and rot. This way, the worms will take care of it before flies and gnats come to lay their eggs.
• Never throw meat or fish into worm compost or vermicompost! Worms are vegetarians.
• Avoid throwing very sweet and juicy fruits that could attract ants.
• Regularly clean the walls and lid of the worm compost/vermicompost bin! It is common for gnats to lay their eggs on the lid.