I turned our kitchen waste into soil on a 4th floor balcony (it smelled for two weeks, sorry neighbours)

Ahh okay so this started because amma was tired of the wet waste bin leaving the house every morning in a plastic bag, and I was tired of buying potting soil for my balcony plants (the small bag costs more than my canteen lunch for a week). I said I'd try composting. My brother said it would stink up the whole flat. He was right for exactly two weeks. omg.

Here's everything, including the failures.

What composting actually is

It isn't "rotting" in the gross sense, it's controlled decomposition. Bacteria and fungi eat the organic matter and, when oxygen is available, they respire:

$C_6H_{12}O_6 + 6\,O_2 \rightarrow 6\,CO_2 + 6\,H_2O + \text{energy}$

That's the aerobic respiration equation from class 11 bio, just done by microbes in a bucket instead of by us. Some of the energy comes out as heat. In a big pile it gets properly hot; in my small bin I could feel it slightly warm for the first few weeks.

The important word is oxygen. With no air, a different crowd of microbes takes over (anaerobic ones), and they produce the smelly stuff, including things like hydrogen sulphide, which gives the rotten-egg smell. That's exactly what happened in my first bin. Landfills are the same situation on a gigantic scale: food waste gets buried, air can't reach it, and it releases methane, which is a greenhouse gas. So keeping wet waste out of the landfill is not just a hobby thing, it genuinely matters.

The setup (cheap)

• One container with a lid. Mine is an old paint bucket a neighbour gave me, cleaned properly.
• Holes drilled all around the sides and a few at the bottom for air and drainage, with an old tray under it.
• A bag of dry leaves from the park, and a handful of cocopeat.

That's it. No machine, no special bacteria powder.

Greens and browns

Compost needs two kinds of ingredients:

"Greens" (wet, nitrogen-rich)	"Browns" (dry, carbon-rich)
vegetable and fruit peels	dry leaves
tea leaves, coffee grounds	shredded newspaper and plain cardboard
crushed eggshells (a little)	cocopeat
cut flowers, plant trimmings	dry grass, untreated sawdust

Microbes need carbon as food and nitrogen to build proteins. The number you see quoted is a carbon-to-nitrogen ratio of about 25 to 30 parts carbon for every 1 part nitrogen. Since browns are carbon-heavy and greens are nitrogen-heavy, the practical rule is more browns than greens, something like 2 to 3 parts brown for each part green by volume. It's a rule of thumb, not physics. Adjust by smell and feel.

What NOT to add: cooked food with oil, meat, fish and dairy (smell and pests), and not too much onion or citrus. Also glossy paper, and tea bags unless you've checked, because many have plastic in the seal.

What went wrong

For the first week I put in only kitchen waste. No browns. It became a wet black soup, the smell was awful, and tiny fruit flies appeared from nowhere. Our neighbour aunty politely asked if something had died in our balcony.

The fix, which I found after reading way too much:

1. Add a big pile of dry leaves and cocopeat and mix everything.
2. Always cover fresh peels with a layer of browns. Fruit flies can't get to the food.
3. Check moisture. It should feel like a wrung-out sponge: damp, but not a drop comes out when you squeeze. Too wet means smell, too dry means nothing happens (and ants).
4. Mix every three or four days with a stick or old spoon. That's how air gets in.

The smell was gone in about three days. I won't lie, I did a small victory dance on the balcony.

The routine now

Every day I toss in peels and cover them with a handful of browns. Every few days I stir. When the bucket is full, I stop adding and let it rest for about 4 to 6 weeks. A spoon of old compost or garden soil mixed in at the beginning helps because it brings the right microbes.

After roughly 6 to 8 weeks the stuff at the bottom was dark, crumbly and smelled like a forest floor after rain. That smell comes from a compound called geosmin, made by soil bacteria, which is also part of why the first rain smells the way it does. I'd been smelling that and never knew it was bacteria. 🌱

Finished compost isn't a fertiliser in the powdered NPK sense. It's more of a soil improver: it adds organic matter and helps soil hold water. I mix about 1 part compost with 3 parts ordinary soil for my pots. My chilli plant is visibly happier. I'm not saying it's because of me, but it is because of me.

Smaller lessons

• Cut peels into small pieces. Big chunks take forever. Coconut shells and corn cobs are basically fossils, I skip them.
• Ants usually mean too dry. Flies usually mean too wet or uncovered. A bad smell usually means not enough air.
• Vermicomposting (using worms) is a different system. It uses special composting worms, not the ordinary earthworms you find in garden soil. I haven't tried it yet.

It's not saving the planet by itself. But one bucket of wet waste a week stays out of the garbage truck's route and comes back as soil for my plants. I've also become the person who looks at other people's peels with great interest. Come try it. It's grosser and easier than you think.