The Complete Guide for Indoor Composting

The concept of composting indoors might seem a bit intimidating—rotting food inside your home? But modern indoor composting has come a long way, and when done correctly, it’s clean, odor-free, and works even in the smallest living spaces. Forget about the messy, smelly piles you might have heard of; indoor composting can be surprisingly easy and effective.

For urban dwellers, especially those in apartments or homes without backyards, indoor composting is a game-changer. In fact, about 80% of Americans live in urban areas, and many don’t have access to outdoor space where traditional composting is possible. So, how can you still compost? The solution is bringing the composting process indoors, in a manageable and controlled way.

Benefits of Indoor Composting:

• Year-round composting: No winter slowdown.
• Convenience: No need to step outside during bad weather.
• Pest protection: You control the environment, keeping pests at bay.
• More control over conditions: You can regulate temperature, moisture, and other variables more effectively.
• Perfect for small spaces: Ideal for apartments, condos, or homes without outdoor yards.

However, indoor composting does require the right equipment designed for indoor use, and it needs more attention than outdoor composting. You’ll need to carefully manage the process to ensure everything stays odor-free and efficient.

Indoor Composting Methods Compared

When it comes to indoor composting, you have a few different options to choose from. Let’s break down the three most popular methods:

1. Electric Composters

How it works: Electric composters use heat and agitation to break down food waste quickly.

• Timeline: Composting can take anywhere from 24 hours to 2 weeks, depending on the model and cycle.
• Cost: Typically ranges from $300-$700.
• Space: Fits easily on your countertop.
• Best for: Those who want the most convenient and fast composting solution.

Electric composters are a top choice for anyone looking to compost with minimal effort. Here’s how they work:

• Add your food scraps into the composting bucket.
• Press start to begin the composting cycle.
• The machine uses heat and mechanical agitation to break down the scraps.
• Carbon filters help capture any odors.
• Once the cycle is complete, the material is processed and ready to use.

What You Can Compost

Most electric composters can handle a wide variety of food scraps, including meat, dairy, and cooked food. However, always double-check the specific model for any restrictions.

What You Get

The end product is processed food waste, which isn’t technically finished compost. It will continue to break down once added to soil, but it can still be used to enrich your garden or houseplants.

Reality check:

The output isn’t the humus-like compost that traditional composting produces. It’s still useful but will need to continue decomposing in your garden soil.

Tips for success:

• Cut food into smaller pieces to speed up the breakdown.
• Don’t overfill the composter.
• Run complete composting cycles to ensure thorough processing.
• Replace filters as needed to keep odors under control.
• Mix the output into soil rather than using it directly as compost.

2. Worm Bins (Vermicomposting)

How it works: In a worm bin, red wigglers (a special type of worm) process food scraps, producing rich fertilizer in the form of worm castings.

• Timeline: Expect about 2-3 months before you can harvest the first batch of castings.
• Cost: A worm bin setup can range from $50-$150, or you can build your own.
• Space: Worm bins can fit easily under a sink, in a closet, or in a corner of a room.
• Best for: Those who enjoy getting hands-on and are willing to care for the system.

Worm composting, or vermicomposting, is one of the most sustainable and eco-friendly ways to compost indoors. Here's how it works:

• Set up the bin with bedding material like shredded paper or cardboard.
• Add red wiggler worms (about 1 lb to start).
• Feed them your food scraps, burying them under the bedding to keep flies away.
• The worms consume the scraps, and over time, they produce nutrient-rich castings (worm poop), which can be used to fertilize your plants.

What You Can Compost

Worms love fruit and vegetable scraps, coffee grounds, paper, and cardboard. However, they don’t do well with meat, dairy, citrus, onions, or garlic.

What You Get

The main product is worm castings, which are excellent for enriching soil and making houseplants thrive.

Reality check:

Vermicomposting requires some learning. You need to balance moisture levels, feeding amounts, and temperature to keep the worms happy and the system running smoothly. But once it’s set up, it requires minimal effort to maintain.

Tips for success:

• Always use red wiggler worms (not earthworms) for the best results.
• Don’t overfeed your worms. Start slow and gradually increase the amount of food.
• Keep the bedding moist but not soaked—moisture control is key.
• Bury food scraps under the bedding to avoid attracting pests like flies.
• Maintain temperatures between 55-77°F and avoid placing the bin in direct sunlight or near heating vents.

Bokashi

Bokashi composting is different from traditional methods—rather than decomposition, it relies on fermentation to break down food waste. This method is particularly useful for those looking to compost everything, including meat, dairy, and cooked food, which are typically off-limits for other indoor composting methods.

How it works:

• Add food scraps to a sealed bucket.
• Sprinkle bokashi bran (which contains beneficial microbes) over the scraps.
• Press down to ensure air is excluded, then seal the bucket.
• Repeat until the bucket is full.
• Let it ferment in the sealed bucket for about two weeks.
• After fermentation, bury the contents in soil or add to your outdoor compost pile.

What you can compost:

Unlike other methods, bokashi can handle everything—from fruit and vegetable scraps to meat, dairy, and even cooked food.

What you get:

The result is fermented pre-compost, which breaks down rapidly once buried in the soil, enriching it with nutrients.

Reality check:

The output can smell sour or pickled (which is normal) but not rotten. You'll need somewhere to bury it—whether in a garden, planter, or even a friend's yard.

Tips for success:

• Always press out the air when adding scraps to the bucket to ensure a proper fermentation process.
• Drain the liquid produced regularly—this "bokashi tea" can be diluted and used as a fertilizer for plants.
• Consider having two buckets—while one ferments, you can fill the other with scraps.
• When it’s time to bury the output, make sure to bury it 6-8 inches deep to avoid odors and pests.

Managing the #1 Concern: Smell

One of the most common concerns about indoor composting is the potential smell. Fortunately, each method has specific steps you can take to keep odors at bay.

Electric Composters:

• Regularly replace carbon filters according to the manufacturer’s schedule to maintain effective odor control.
• Don’t leave scraps sitting in the composter for days before running it—run it regularly to prevent smell buildup.
• Clean the bucket between cycles to ensure freshness.

Worm Bins:

• A bad smell usually signals an issue with the system—perhaps it’s too wet, overloaded with food, or containing the wrong types of scraps.
• Always bury food scraps beneath the bedding to prevent odors.
• Maintain proper moisture levels—think of a wrung-out sponge. Too much moisture can lead to problems.
• Avoid composting onions, garlic, and citrus, which can create an imbalance.

Bokashi:

• Keep the bucket sealed at all times except when adding food scraps to avoid exposing it to air.
• Don’t open the bucket just to check on it—this can let in air, which can cause smells.
• The sour smell when opening is normal—it’s a sign that fermentation is occurring, but it shouldn't smell rotten.

Collection Bins:

• Empty your scraps bin every 2-3 days to prevent smells from accumulating.
• Choose a collection bin with a good seal. Some even come with built-in carbon filters to reduce odors.

Space Requirements

Indoor composting doesn’t require a lot of space, which is great for apartment dwellers. Here’s what you’ll need:

• Electric Composter: About the size of a bread maker. It can fit easily on your countertop or in a cabinet with proper ventilation.
• Worm Bin: Typically around 10-20 gallons, similar to a large storage tote. These fit well under a sink, in a closet, or tucked in a corner.
• Bokashi: You’ll need two 5-gallon buckets. These can easily be stored under the sink or in a closet.

The key to success is finding a spot with the right temperature and easy access, especially since electric composters and worm bins have specific temperature preferences for optimal performance.

What to Do With the Output

Once your composting system is up and running, you’ll need to know what to do with the end product. Here are a few ideas:

• Houseplants: Mix finished compost or worm castings into potting soil. Plants will thrive with the added nutrients.
• Balcony Containers: If you have outdoor containers for plants, adding compost to the soil will improve plant growth.
• Community Gardens: Many community gardens welcome compost donations or allow you to add to shared beds.
• Give it Away: Friends who garden will appreciate receiving worm castings or processed compost.
• Offer to Neighbors: Those with beautiful flower beds may be grateful for free fertilizer.

Starting Your Indoor System

If you’re new to indoor composting, it can seem like a lot to manage at first. But the process is straightforward, and once you get the hang of it, it becomes second nature. Here’s a simple timeline for getting started:

• Week 1: Choose your composting method based on your available space, budget, and how much effort you want to invest.
• Week 2: Get your equipment. Whether you’re ordering or buying in-store, set up your system according to the instructions.
• Week 3: Start collecting food scraps. Keep a small countertop bin to collect scraps as you prepare meals, and begin feeding your system.
• Week 4: Observe and adjust. Check how your system is responding. If necessary, tweak moisture levels, food amounts, and other factors.
• Month 2 onward: Settle into a routine. By now, composting will feel like second nature, and you’ll have a rhythm.

The Bottom Line

Indoor composting is a practical and effective solution for those with limited outdoor space. Millions of people successfully compost indoors in apartments, condos, and small homes. The key is selecting a composting method that fits your lifestyle and commitment level:

• Want it easy? Go for an electric composter.
• Want the best output? Try a worm bin.
• Want something affordable? Bokashi is a great choice.

Start simple, learn along the way, and don’t worry about making mistakes. With the right system and a bit of patience, you’ll be composting indoors successfully in no time!