Indoor composting works in a small space with the right container and method
You can compost indoors using a sealed bin, a worm bin, or a countertop electric composter. The method you choose depends on your space, how much food waste you produce, and how quickly you want finished compost. Indoor composting does not have to smell if you follow basic rules: balance wet and dry materials, keep the bin sealed, and maintain the right moisture level.
The three most common indoor methods are vermicomposting (using worms in a bin), bokashi fermentation (using special bran to break down food), and electric composters (machines that heat and grind waste). Each produces usable compost or pre-compost in weeks to months, not the year or more that outdoor piles take.
Key Takeaways
- Worm bins (vermicomposting) are the cheapest indoor option and work in apartments, but require feeding worms regularly and take two to six months to produce finished compost.
- Bokashi buckets ferment food waste in two weeks, then need to be buried or added to outdoor compost, making them useful only if you have outdoor space or a community garden plot.
- Electric composters break down food in hours to days and produce a dry material you can use in potted plants, but cost $300 to $500 and use electricity.
- Indoor bins need a lid, drainage holes, and a balance of "brown" materials (shredded paper, cardboard) with "green" materials (food scraps, coffee grounds) to avoid smell.
- Fruit flies and mold are the most common problems, both prevented by burying food scraps under brown material and keeping the bin sealed between feedings.
Worm bins: the cheapest method for apartments
A worm bin (vermicomposting system) holds red wiggler worms that eat your food scraps and produce finished compost called castings. You can buy a ready-made bin for $40 to $150, or build one from a plastic storage container with drainage holes drilled in the bottom. The bin sits under your sink, in a closet, or on a balcony and produces no smell if maintained correctly.
Feed the worms once a week by burying food scraps under a layer of shredded newspaper or cardboard. The worms eat the scraps over several days, then you add more. After two to six months, the bottom layer becomes dark, crumbly castings that you harvest and use in houseplants or outdoor gardens. One pound of worms (about 1,000 worms) handles the food waste from one or two people.
Worm bins work best in temperatures between 55 and 77 degrees Fahrenheit. If your apartment is much colder or hotter, the worms slow down or die. You also cannot compost meat, dairy, oils, or pet waste in a worm bin — only plant-based food scraps, coffee grounds, and paper.
Bokashi buckets: fast fermentation for small spaces
A bokashi bucket is a sealed 5-gallon container with a tap at the bottom. You layer food scraps (including meat and dairy, unlike worm bins) with special bokashi bran, which contains microbes that ferment the waste. After two weeks, the bucket is full of fermented material that looks like wet garbage but smells like vinegar or beer.
The fermented material cannot be used directly in plants — it must be buried in soil or added to an outdoor compost pile for another two to four weeks before it breaks down completely. If you have no outdoor space and no access to a community garden, a bokashi bucket leaves you with a bucket of material you cannot use. Bokashi buckets cost $30 to $80, and the bran refills cost $10 to $15 per bucket.
Bokashi works well if you produce a lot of food waste and want to ferment it quickly before taking it to an outdoor location. The tap at the bottom drains liquid (called bokashi tea) that you can dilute and pour on houseplants.
Electric composters: finished compost in hours
An electric composter is a countertop machine that heats, grinds, and dries food scraps into a dark, crumbly material in 3 to 8 hours. Models like Lomi, Vitamix FoodCycler, and Ninja Compost produce material that looks like finished compost but is technically pre-compost — it still needs to be mixed into soil for a few weeks before plants can use it fully.
Electric composters cost $300 to $500 and use about as much electricity as a microwave. They handle all food types, including meat and dairy, and produce no smell because the machine is sealed. The finished material takes up about one-fifth the volume of the original scraps, so you empty it once a week or less.
The main drawback is cost and the fact that the material is not true finished compost — it is dehydrated and partially broken down. If you have houseplants or a small garden, you can use it directly by mixing it into potting soil. If you have no plants, you are left with material to store or dispose of.
Building a straightforward indoor bin from household items
You can make a basic indoor compost bin from a plastic storage container with a tight-fitting lid. Drill or poke holes in the bottom for drainage and holes near the top for air flow. Place the bin on a tray to catch liquid that drains out. Fill it with alternating layers of shredded newspaper or cardboard (brown material) and food scraps (green material), starting and ending with brown.
Keep the bin in a cool, dark place like under the sink or in a closet. Once a week, stir the contents with a fork or stick to add air. The compost is ready when it is dark, crumbly, and smells like soil — usually in two to four months. This method is slower than electric composters and produces less finished material than worm bins, but it costs almost nothing.
The key to avoiding smell and fruit flies is the brown-to-green ratio. Aim for roughly two parts brown material to one part green material by volume. If the bin smells like ammonia or rotting food, add more shredded paper. If it is dry and not breaking down, add more food scraps and a little water.
Preventing fruit flies, mold, and odor
Fruit flies are attracted to exposed food scraps. Prevent them by burying all food waste under at least two inches of brown material (shredded paper, cardboard, or dried leaves). Keep the bin sealed between feedings. If flies appear, stop adding food for a week and let the bin dry out slightly, then resume with more brown material on top.
Mold is normal in compost and usually harmless, but white or gray mold means the bin is too wet. Add more brown material and reduce watering. Black or slimy mold means the bin is anaerobic (lacking oxygen) — stir it and add more air holes.
Odor comes from too much moisture or too many green materials. If the bin smells like ammonia, add brown material and stir. If it smells like rotten food, reduce how much you feed it and add more brown material. A properly balanced bin should smell earthy, not unpleasant.
What you can and cannot compost indoors
Safe to compost: fruit and vegetable scraps, coffee grounds and tea bags, crushed eggshells, shredded paper, cardboard, leaves, grass clippings, and plant trimmings. In worm bins only: avoid meat, dairy, oils, and pet waste. In bokashi and electric composters: you can include meat, dairy, and oils because the fermentation or heat breaks them down.
Never compost: diseased plants, weeds with seeds, glossy or colored paper, pet waste, or anything treated with pesticides. These either spread problems or do not break down safely indoors.
Frequently Asked Questions
Can I keep a compost bin in my apartment without it smelling?
Yes, if you keep it sealed, bury food scraps under brown material, and maintain the right moisture level. Worm bins and electric composters are the most reliable for odor control. A sealed plastic bin works if you follow the brown-to-green ratio and stir weekly.
How long does it take to get finished compost indoors?
Worm bins take two to six months. Electric composters produce material in hours but it needs a few weeks in soil to fully break down. A straightforward sealed bin takes two to four months. Bokashi takes two weeks to ferment, then another two to four weeks after being buried or added to outdoor compost.
What do I do with the finished compost if I have no garden?
Use it in houseplants by mixing it into potting soil. Give it to friends or neighbors with gardens. Donate it to a community garden or local park. If none of those work, you can dispose of it in the trash — it is just soil at that point.
Do worm bins really not smell?
A healthy worm bin smells like soil or forest floor, not like garbage. If it smells bad, it is usually too wet or has too much food. Bury scraps under paper, reduce feeding, and add brown material. Worms also need air, so make sure the bin has drainage holes and is not packed too tightly.
Can I compost meat and dairy indoors?
Not in a worm bin — worms cannot process them and they attract pests. Bokashi buckets and electric composters can handle meat and dairy because fermentation or heat breaks them down. If you use a straightforward sealed bin, avoid meat and dairy to prevent smell and flies.