How to choose your compost bin?

Nowadays, it has become easy to store food waste in our daily lives thanks to compost bins (also known as bio-bins) and the compostable bags that often accompany them. These two items play a key role in the success (or failure) of organic waste sorting at home. But with so many different models, sizes, materials, filters, and bags available, it's easy to make a mistake. Too small, too thin, poorly ventilated...

Want to compost, or at least sort your organic waste?

The reality is that it all starts in your kitchen, when you have a carrot peel in your hand. And at that moment, either you have a clean, accessible, well-designed container... or you give up. The compost bin—or compost container, box, tub, bucket, whatever you call it—is not a logistical detail. It's what makes the gesture feasible or not. And that's often where it gets complicated.

A well-chosen compost bin helps prevent:
- Odors within two days, especially in summer
- A brownish layer of juice that is impossible to clean (and continues to smell for a long time)
- A lid that you no longer dare to open A bag that tears when you take it out
- Gnats, because there is no ventilation or too much moisture

Most models are advertised as "ideal for an average household." But in reality, your needs are anything but average.
The size of a compost bin depends solely on three things:
- How many people live in your household
- How often you are willing to empty it
- How much organic waste you actually produce (depending on your cooking habits)
- A bin that is the wrong size, too small or too large, quickly becomes a daily inconvenience.

Which size should you choose for your household?

On average, a household that cooks regularly produces between 1 and 1.5 liters of bio-waste per person per day. The ideal volume of the bin then depends mainly on how often you want to empty it.

For a single person, a 3- to 4-liter bin can usually be emptied every two to three days.

For a household of two to three people, a 6- to 8-liter bin is suitable for emptying every two days.

Finally, for four to five people, a 9- to 12-liter bin is necessary for daily emptying.

Note that if you cook infrequently, but your community composter is far away or collection is infrequent, it may be a good idea to opt for a slightly larger bin to limit trips back and forth.

How can bio-waste be stored sustainably?

A well-designed, slightly ventilated bin, used correctly, can store your organic waste for 2 to 3 days without any problems, even in summer.

A few simple precautions:
- Avoid foods that are too moist or decompose quickly (fish, meat)
- Add kraft paper, cardboard, or dry coffee grounds to balance moisture
- Do not compact your waste: a little air = less juice

What materials should be used for a compost bin?

All compost bins promise easy sorting and no odors. But the reality is more nuanced. It's not a question of price or design, but rather essential criteria that make all the difference in everyday use.

Stainless steel: sturdy, odor-neutral, easy to clean, but heavier and more expensive
Recycled plastic: lightweight, economical, moisture-resistant, but can retain odors if of poor quality (and beware of microplastics, see more details below)
Wood or bamboo chipboard: attractive, but absorbs moisture, stains easily, and can wear out quickly
Enamel or ceramic, or even glass: easy to clean, good odor resistance, but heavy and fragile

The most important thing is to choose a smooth, non-porous material that does not retain juices or odors. Stainless steel and good-quality plastic are the best options if you are looking for easy maintenance.

Microplastics: an often overlooked risk

Acidic organic waste can damage certain plastic surfaces over time. The main factor in the transfer of microplastics to waste is mechanical wear: scratches and abrasion. An intact plastic bin, used at room temperature, does not pose a major risk. However, a scratched bin or one that has been cleaned with harsh products can release particles into your bio-waste, which do not disappear during composting.

Practical advice:
- Always clean with the soft side of the sponge
- Avoid abrasive or acidic products
- Replace a worn plastic bin, or opt for stainless steel

Ventilation and airtightness: striking the right balance

Contrary to popular belief, an airtight container traps moisture, promoting fermentation and odors. A slightly ventilated container, ideally with a perforated lid and an activated carbon filter, allows moisture to escape and limits the formation of juice and unpleasant odors.

Exception: if you empty the bin every day or store it in the freezer, airtightness becomes less crucial.

Some high-end models use a partial vacuum system to slow down the fermentation of waste. This system can be useful if you don't empty your bin for several days and you have a lot of wet and sensitive waste (fish, meat, very ripe fruit). But in most cases, a well-used ventilated bin is more than enough. The vacuum does not compensate for poor sizing or insufficient cleaning. It is an option, not a miracle solution.

Ergonomics and cleaning: keys to success

In terms of ergonomics, let's remember the practical aspects: a practical compost bin should:
- Have a lid that is easy to open with one hand
- Have a sturdy handle for leak-free transport
- Be easy to clean, with no hard-to-reach corners or grids
- Regular cleaning with hot water and vinegar (or dishwasher safe) is sufficient to prevent odors.

Why choose biodegradable bags?

In practice, biodegradable bags have a specific and concrete role:
- Facilitating the transfer of organic waste from the bin to the composter or collection point, without spills or leaks
- Reducing the amount of cleaning required for the kitchen compost bin, which increases motivation to sort waste
- Improving hygiene by reducing direct contact with wet waste
- However, it is important to note that their effectiveness depends on the quality of the bag and how it is used. A bag that is too thin or poorly chosen may tear when emptied, complicating the entire process. And a non-certified bag may pollute the compost or not degrade properly.

Which compostable bags should you choose depending on their use?

The most common compostable bags are made from:
- Corn starch (PLA)
- Cellulose
- Biodegradable plant materials

Bags certified according to European standards offer a better guarantee of compostability. Kraft or reinforced paper bags can be an alternative for less moist waste, but their resistance to moisture remains limited.

‍Key takeaway: A biodegradable bag that is well suited to the type of waste and frequency of emptying facilitates high-quality compost. Certified bags, although slightly more expensive, offer better degradation during composting. For home composting, avoid bags that are too thick, as they slow down the process.

Mistakes to avoid with compostable bags

- Using a bag that is too thin and tears as soon as it contains a little juice or weight
- Using a non-certified bag that will not compost properly and will pollute your compost
- Confusing biodegradable with compostable: not all biodegradable bags are compostable under normal conditions
- Underestimating the recurring cost: compostable bags are an expense that must be included in your composting budget

Frequently Asked Questions

What size compost bin should you choose for your household?
Allow for approximately 1 to 1.5 liters of organic waste per person per day. Then adjust according to how often you want to empty it: a household of 2 to 3 people emptying it every 2 days will need a 6 to 8-liter bin.

‍Are compostable bags really necessary?
They make transport easier and reduce the amount of cleaning required for the compost bin, but must be chosen carefully to avoid tears and unpleasant surprises. A certified bag, suitable for the type of waste, is recommended.

‍How can you prevent bad odors in a compost bin?
Choose a slightly ventilated bin, avoid compacting the waste, add paper or cardboard to absorb moisture, and empty it regularly. Storing the bin in a cool place or in the refrigerator is also a solution.

‍Can the plastic in compost bins contaminate organic waste?
‍High-quality plastic that is free of scratches and mechanical wear does not pose a major risk. Avoid abrasive sponges and replace bins that are too worn to limit the migration of microplastics.

‍What is the vacuum system in some compost bins?
‍This is a process that reduces the amount of air in the bin to slow down waste fermentation and limit odors. It is useful if you do not empty your bin often, but not essential for regular use.