What would happen if you started composting kitchen waste indoors, in your own home, with worms?
Composting is seeing a great come back as more and more people want to contribute to a more sustainable life.
It’s a natural process which has been occurring since the beginning of life. Sounds grand and philosophical but it’s true: wherever vegetation or an animal dies it’s being decomposed slowly and steadily, helped by micro and macro organisms.
Without it, the circle of life wouldn’t exist. Composting is a natural process happening wherever organic matter is left alone to be decomposed by micro and macro organisms, creating what gardeners affectionately call ‘black gold’. Nature doesn’t know waste. Organic output somewhere becomes someone else’s food.
Composting – Why Bother?
3 main reasons why composting is one of the easiest ways to live sustainably.
- It turns organic waste into a valuable resource.
- You lower your carbon footprint because there is no need for transporting and managing waste in landfill.
- Using compost improves the quality and health of soil without the use of chemicals.
[LINK more reasons to compost]
3 Ways to Compost Indoors at Home
There are three different ways to produce compost indoors. Knowing what to expect will make it easier for you to decide which one is most suitable for your circumstances and likes.
- Vermicomposting indoors (Composting with worms)
- Bokashi fermenting and composting
- Traditional composting
Just in case you wonder where kitchen compost bins fit in this list: well, they are really just a container to collect food scraps in. They are then moved to a compost bin or composting facility in your area.
Vermicomposting vs Bokashi vs Traditional Composting
|Vermicomposting||Bokashi Fermenting||Traditional Composting|
|Suitable for Indooruse?||YES||YES||Not really|
|What can be composted?||Almost all plant based kitchen waste, cooked and uncooked (no citrus fruit or onion scraps!)||All meat and plant based kitchen waste||All uncooked plant based kitchen waste|
|Cost of Compost Bin||UK: from £60 + worms|
USA: from $75 + worms
|from £50 incl bokashi bran||from £30|
if using worm bins with drainage taps to self-regulate humidity
|EASY||MEDIUM – requires ongoing monitoring of humidity to avoid smells|
|Ongoing Costs (ball park figures)||None||yearly for Bokashi bran:|
UK: ca £20 for 3kg
US: ca $50 for 5lb
|Time to finished Compost||Depends on loads of factors like temperature, amount of worms vs amount of food, nature of worm food etc.|
A feed through system usually takes 6 months for first harvest and becomes faster as number of worms increase
|Fermented after 2 weeks + 2 weeks composting in ground||Kitchen scraps: 6 to 12 months|
|Quality of Compost||Black, crumbly humus, high in nutrition and disease preventing qualities, can be added straight to soil||Looks almost like original food waste after fermentation, needs further composting – happens quickly||Black/ brown crumbly, often fairly high amount of bulk material|
As you can see from the table above there is a lot to be said for vermicomposting. Worms help to compost kitchen scraps faster and the vermicastings (worm poo) have added microbial activity and even better characteristics for plants than traditional compost.
Furthermore, this has to be one of the easiest methods to turn your plant based food scraps into rich compost and compost tea. Yepp, that’s right: compost tea – more about that later.
How does vermicomposting indoors work?
Vermicomposting mimics what’s happening outdoors in a garden, a field, forest, well anywhere in nature where there is vegetation. When plant material dies micro and macro organisms including worms break it down and make its components available for new plant growth.
How do you bring this part of nature inside?
You need to set up a home for worms (the right kind), let them settle in and provide them with food. That’s it. Once set up you only add your veggie and fruit peels and leftovers to the bin as and when they occur. Composting worms feed on the microbes which multiply as the material rots.
Every few days you drain a bit of potent liquid called leachate. This is the liquid which stems from the kitchen scraps and percolates through the bin, picking up more microbes along the way. This is not really compost tea, yet but can be diluted to water plants with.
After a few months you harvest your first nutrition-rich compost to add to soil or create compost tea from.
That’s the process in a nutshell. In the next chapters we will look at all of this in more detail so you know what it could look like in your home and how easy it is.
1. Getting a Home for Composting Worms
How do you to choose your worm compost bin? Should you make your own or go for a ready made wormery composter?
If on a tight budget or if the thought of a little DIY project makes your hands itch in anticipation you can very well make your own worm compost bin [LINK].
However, I would still recommend buying the first two handful of worms to get you started because the worms you find out and about are very likely NOT the ones best suited for chomping away in a wormery.
If you are like me and want to get on with it and prefer the neat look of a purpose build unit you need to go shopping (unless you source a second hand one but you’ll find there aren’t many about which just shows how people tend to stick with their wormeries because they work brilliantly).
A ready made wormery usually comes with a tap to conveniently remove the liquid which accumulate at the bottom. Most DIY solutions on the other hand need to be managed more carefully to avoid a soggy mess.
To make it easy for you we keep an eye on all that’s available and compiled an in-depth review of the best wormery composters in the UK here and in the US here. [LINK]
A new, commercially available wormery will set you back about £60 in the UK for a simple bin type design with a tap. More popular are stacking and flow through type wormeries starting at £70 for the bin itself. You will add to this a starter pack of worms which sometimes is included in the offer.
All of this is a one time investment and there is nothing else you’ll need to buy in the future to maintain your worms’ keep.
2. Making a Home for Worms – Bedding
Worms need a home and time to settle in. A home for them doesn’t mean to be drowning in food or work if you like. Prime estate for worms will be moist and allow airflow, have a neutral ph, be non-toxic and have the right kind of temperature.
Tried and tested bedding materials for the wormery are:
- Leaf mould
- Damp shredded paper and/or cardboard bits
- Vermicompost from an established bin
Planet Alert: Some sources list peat compost as a bedding material for worms. However, a layer of 1m of peat takes 1000 years to form. Peat bogs are such an important and irreplacable environment for wildlife and as a water regulator that using peat for garden purposes is now deemed irresponsible. Make sure you read the label when buying compost and it should say ‘peat-free’.
Preparing the Wormery for Worms
- Lay a sheet of newspaper on the lower tray to prevent the following material from falling through the holes. Place the environmentally friendly bedding material about an inch high into the first tray of your wormery. You don’t need to compress it, a fluffy inch will do.
- Once the first bedding is in you can release your worms into their new home. Place them on top of the bedding and leave as is. Worms are very light sensitive and will go into hiding in the bedding right away.
- Add a small handful of green food waste to one corner.
- You can then cover the layer with a piece of cardboard, some Hessian – anything that is compostable and can absorb and therefore regulate moisture. Put the cover right on top of the bedding. The cover keeps the composting material moist. You could also think of the cover as a blanket for the worms because they like to come up and snuggle right under it.
I like to use a piece of brown corrugated cardboard. This does in time get soft due to the humid conditions. The worms start to crawl into the gaps of the cardboard, stretching out all along those ridges and seem to like to have a break in there. Eventually it biodegrades and gets eaten and I replace it with another piece.
Planet alert: Wormery suppliers often supply a coir mat with the starter kit to use as a first bedding. This works very well but I wouldn’t go out and buy one because coir is made of coconut fibre, so is obviously transported a long distance to the UK which means it uses energy and goes against the principle of using materials that are available locally to lower the carbon footprint.
Worms will need up to a week to settle into their new home. That is after that time they will stop escaping the bin.
3. Adding Food for Worms
Finally, your worms have settled in, no more escapees. Now what?
Now you can start adding little amounts of food scraps. How much is a little amount? You’ll often find references that worms can eat half their body weight per day.
However, this only applies when all conditions are perfect. This includes temperature and how soft and broken down the food is already. Worms only eat soft, decomposing organic matter. The worms will therefore not touch the fresh carrot or potato peels until they go soft and mushy.
I just add any leftovers as and when I have them trusting that the worms have enough decomposing matter already in the bin to feed on while the fresh stuff starts to be attacked by microbes.
4. Beyond the Initial Enthusiasm – is Vermicomposting Indoors Sustainable?
This is easy to answer: Yes! Here is what would change for you if you’d switch from throwing plant based food left-overs in the bin to feeding your worms.
- Instead of binning peelings and food scraps you’d put them in a wormery – same effort.
- Every now and then, you add some newspaper or torn up cardboard to the wormery – again not much additional effort compared to putting those materials in a bin.
- 2 to 3 times a week you need to drain and collect the liquid which accumulates at the bottom of the worm farm – 3 min tops.
- After the first 6 month and then every 1 to 2 months the compost is ready to be harvested. This is the biggest additional task that comes with a wormery. Harvesting means you take the lowest tray and remove any remaining worms.
Vermicomposting – Summary:
✅ A wormery is a great way to compost indoors: easy, silent, local with a great soil amendment as a result.
✅ Odour-free if done correctly and that’s not hard to do (do not add too much food at a time and no citrus, onions peels and animal produced stuff like fat and dairy)
❌ – Vermicomposting can’t decompose meat, oils and fats, dairy and pet waste.
READ more about the Dos and Don’ts of setting up a wormery bin indoors here.
Dairy and Meat Waste – How does Composting with the Bokashi System Work?
Composting with worms is great for almost any plant based kitchen scraps. But if you are not vegetarian or vegan you are likely to have other food waste as well.
What to do? Enter Bokashi.
The Bokashi method itself is not composting but a fermenting process of kitchen waste like bones, meat, dairy and plant material. It’s an accelerator towards composting and fermented kitchen waste is ready to be dug into soil for further composting. It can also be added to a traditional compost heap or bin.
Unlike traditional composting and vermicomposting which need air for microbes and worms to do their work, Bokashi is an anaerobic treatment which means oxygen needs to be excluded as much as possible. Therefore it happens in an airtight Bokashi bucket with the help of Bokashi bran to introduce the right kind of microorganisms.
The food leftovers are placed in the Bokashi bucket, pressed down with a lid to get as much air out as possible, sprinkled with the bran and after 2 to 3 weeks everything should be fermented, ready to move onto the next process.
The Bokashi process provides another valuable resource: Bokashi juice, an acidic liquid which is drained regularly and can be put to use to clear drains organically, diluted as fertilizer or to reduce the growth of algae.
Bokashi – Pros and Cons
✅ Works well indoors
✅ Bokashi fermenting turns almost all kitchen waste into a valuable resource, ready to be dug into soil for last composting
❌ Bokashi doesn’t provide compost but prepares kitchen waste including meat and dairy which would otherwise go into a bin for composting.
3. Traditional Composting indoors
Traditional composting means that micro and macro organisms decompose plant material over time. The environment needs to be within certain oxygen and humidity levels. This is where traditional composting becomes somewhat difficult to manage indoors. It can easily get too dry or too wet and smelly, especially in an indoor container which is likely to be fairly small and can therefore get easily out of balance.
There are ways to remedy by turning the composting material to aerate and by adding dry material like cardboard. So it’s not impossible but compared with vermicomposting or Bokashi it’s more difficult to monitor and manage on a daily basis.
VERDICT: Traditional composting is possible indoors but needs close monitoring – not recommended to do inside.