Getting rid of my kitchen waste does feel a bit like filing food sometimes.
I have one bin for chicken food, another for compost waste, and a final one for food that goes out in the trash.
I also have a fourth bin that sits in the work kitchen, collecting items like coffee grounds and banana peels – all of which goes straight to my compost bin.
In short, I’ve been using kitchen compost bins for years, and I’ve used everything from a standard food waste container to an odor-proof bin with an activated charcoal lid to do so.
I’ve had the odd occasion where they have got smelly, but I’ve also learned that smell is easy to avoid.
So in this article, I’ll be sharing some of the things I’ve learned, so you can avoid odors from your kitchen compost bin.
What is a kitchen compost bin?
Kitchen compost bins are usually not composting bins – i.e. they are not actually used to make compost!
Instead, they are designed to store organic material such as leftover food until they are ready to be put in the compost heap.
There are other systems that allow you to process food inside the house. Usually, these do not produce actual compost, but they can produce something which you can use to fertilize the soil. We’ll cover these later in the article.
Also see: Best Kitchen Compost Bins Round-Up | How to Use a Kitchen Compost Bin
How much of a problem are odors from kitchen compost bins?
First, it’s worth remembering that you are always going to be storing some waste food. Where I live, waste is picked up once a week, and during that time it can get smelly.
In contrast, if you have your own composting system you can have much more control over the odor, as you can choose when it gets removed from the kitchen and added to the compost.
Reasons for Smelly Kitchen Compost Bins
When you add food waste to a bin, microorganisms such as bacteria and fungi start to break it down. In the process, they release gases. The worst gases are those caused by bacteria that don’t need air to be active.
There are a number of factors that contribute to this…
Time in the bin
If you cook at night and throw your waste in the compost the next morning, you probably won’t have to worry about the smell at all. The less time your waste spends in the kitchen, the less time bacteria and fungus will have time to start reproducing.
Heat and Climate
You can get away with leaving your waste longer when the air temperature is cool. Generally speaking, the hotter the conditions are, the sooner your bin will start to smell.
What’s in the bin
As you are probably well aware, some foods (such as fish!) can cause a smell relatively quickly. Other foods, such as onion peels, can take longer to decompose.
In general, unless you are an experienced composter with a hot composting system, it’s best to avoid composting meat, fish and dairy products. Not only can they cause smells more quickly, they can also attract pests in the compost bin or heap if not composted correctly.
Of all of these items, I’ve found fish in particular to be the trickiest. However, with hot compost and sawdust, it is possible you can compost fish.
Air in the bin
As mentioned before, bacteria that don’t need air make more smell than bacteria that need air. For that reason, if your bin has no access to air it could smell more.
Solutions to Prevent Smelly Kitchen Compost Bins
Best options
Regular emptying
This really is one of the keys, and the more regularly you empty your bin the less you will need to take the other steps here. While it can feel like a pain in the morning, take pleasure in the thought that it does you good to get exposed to the early morning sun!
Exactly how often you need to empty the bin, of course, will depend on other factors mentioned above, such as temperature levels and the materials you are keeping.
Activated charcoal filter/Odourless kitchen compost bin
Many kitchen compost bins come with an activated charcoal filter. These are brilliant at filtering out smells. The filters don’t last forever, and I find after I have used a bin for a while they do tend to come off. However, if you don’t mind replacing it from time to time this is an excellent option for reducing smells.
One stylish option is the Joseph Joseph Intelligent Waste bin. It combines a general trash bin with a removable compost bin.
Both the main bin and the compost bin have charcoal filters to absorb smells, while the ventilated compost bin allows air to circulate to reduce moisture.
Location
If possible, keep your compost bin in a cool place and out of direct sunlight to reduce the temperature in the bin.
Drain liquid
If you are keeping materials in your bin for a while, you can drain the liquid (known as leachate) which collects in the bottom of the bin to reduce smells.
Pop it in the freezer
If you are unable to empty the waste as regularly as you need to, you can always pop it in the freezer. You can then simply take the waste to the compost bin or heap it when it is convenient.
Lining the bin with newspaper
Lining the bin with newspaper can help absorb some of the odors from organic waste. The paper helps to trap the smell and keep it from spreading.
The newspaper can be composted when it is finished. As it is a brown (high carbon) material, it will help balance the high nitrogen kitchen waste you have added.
Add baking soda
You can also add baking soda to a bin, which acts as a compost deodorizer.
When it comes into contact with an odor, the molecules of the baking soda bind to the molecules of the odor, trapping them and preventing them from being released into the air.
Add essential oils to the bin
Essential oils are natural aromatic compounds found in plants. When these oils are diffused into the air, their molecules interact with the airborne bacteria that cause unpleasant odors. The oils act as a natural disinfectant, killing the bacteria and neutralizing the odors.
Other options
Add a layer of sawdust, soil or compost
Sawdust is used with composting toilets. A scoop of sawdust is poured over the excrement to stop smells.
So, as you can imagine, it is an excellent biofilter. However, I have included this under other options as it can get everywhere if you are not careful!
Other alternatives include adding a layer of soil or compost.
Add browns
As we have seen, compost without air smells more than compost with air. That’s because anaerobic material does the work. Theoretically, if you add ‘browns’ or high-carbon material like cardboard or paper it should reduce the smell.
Again, I’ve included this under other options, as trying to balance greens and browns on a daily basis adds work and complication to what should be a simple process.
Sub-optimal solutions
Compostable bags
Much is made of compostable bags as a solution. However, many compostable bags don’t compost in an average home compost heap or bin. I’ve tried to compost them in my heap and in a Bokashi bin, and neither time did it work.
How to make compost/pre-compost inside
Composting inside is a different matter, of course. Instead of simply collecting compost for a few days you could, depending on the system, be keeping the compost in a bin for weeks on end.
Let’s have a look at the different options.
Bokashi bins
Bokashi bins do not actually produce compost. Instead, they produce a pre-compost that needs to be dug into the ground or the compost heap. They are a popular solution for indoor composting, though, and so worth including here.
Bokashi bins are not odorless. They produce a fermented/pickling smell as opposed to a rotting food smell. Most people find this inoffensive, some people like it, and some people loathe it. See our guide to Bokashi bins for more information.
Worm bins
If you’re brave enough to share your home with dozens of ‘red wriggler’ worms, you might consider having a worm compost bin. Compost worms, usually the ‘red wriggler’, not only help break down the material, they can also remove diseases like E-Coli!
As long as your worm bin is set up correctly it should not smell.
Also see: How to Build a DIY Worm Bin In 20 Minutes
Cardboard box composting
Cardboard box composting is little known in the West, but is popular in Japan. The composting takes place in a well-ventilated corrugated cardboard box in which you place coco peat and rice husk charcoal. (Hardwood ash can also be used.) You can then add your kitchen scraps.
The ash absorbs any liquid. As long as the box is well-ventilated, aerobic composting will take place, ensuring there are no foul smells. You do need to cover the top with an insect-proof screen (an old t-shirt will do).
You can find cardboard box instructions here (use Google Translate to view them in English.)
Compost Grinders
Compost grinders or electric compost bins reduce the volume of kitchen material, and many dehydrate or treat the material to remove any odors.
Systems like the Vitamix Food Cycler can handle materials the average kitchen bin/compost can’t, such as meat and bones. They don’t actually produce compost, but the result will still contain nutrients and can be added to your compost heap or soil.
Related article: Is the Reencle Electric Composter Too Good to Be True?
Wrapping up
The danger of writing a long guide like this is that it can make composting sound complicated.
It’s not.
If you do nothing else other than collect the right ingredients and empty your bin regularly, your waste won’t smell in most climates.
If you empty your waste less regularly, consider a bin with a charcoal filter, as this is an excellent way to eliminate odors.
FAQs
If your kitchen compost bin has already developed a smell, you can try adding a few drops of an essential oil such as lemon or tea tree oil to help mask the odor. You can also try stirring the contents of the bin to help aerate it, or adding a few tablespoons of baking soda or charcoal to help absorb any odors.
Once your kitchen compost bin is full, you can transfer the contents to an outdoor compost pile or bin. If you don’t have an outdoor composting area, you can find compost collection services in many cities.
You should avoid putting any animal products such as meat, fish, or dairy in your kitchen compost bin, as these can create odors. You should also avoid putting in anything that is not biodegradable, such as plastic, metal, or glass.
Use a sturdy, well-designed kitchen compost bin with a tight fitting lid.
Read more
Kitchen Composting Guide
Best Kitchen Compost Bins Round Up
How to Keep Fruit Flies Out Of Your Kitchen Compost Bin
How to Keep Your (Outdoor!) Compost Bin or Heap From Smelling
Home Composting Guide
Hi, I am seeking some advice about my compost. Around this time last year I bought an indoor compost and began using it. I then put it outside and continued to use it. Around December 2022 it became very liquidy and smelly. I put some on one of my plants and the liquid killed the plant.
I basically haven’t touched it since. I live in Perth and the compost gets sun so I can imagine it has gotten very hot.
I am now too worried to open it as it has been so long. In honesty, I am concerned it will be toxic when I open it.
What do I do?
Some people do advise wearing a mask when you handle compost. That’s usually for handling dry compost because it spreads spores, but if you’re worried a mask and gloves might be reassuring.