I’m going to be upfront: I started composting because of guilt. Every time I scraped vegetable peels and coffee grounds into the kitchen bin, I thought about the fact that roughly a third of Finnish household waste is organic material that could decompose naturally instead of being trucked to processing plants. I’d been writing about sustainable living at home and talking about reducing waste, and yet there I was, tossing banana peels into a plastic bag destined for the mixed waste bin.
So in August 2024 I bought a Kekkilä home composter. The 230-liter model, dark green, with a hinged lid and a hatch at the bottom for harvesting finished compost. It cost €89 from K-Rauta. I set it up in the corner of the shared yard behind our building (with the housing association’s permission — more on that later), threw in my first handful of apple cores, and felt enormously pleased with myself.
That feeling lasted about three months. Then the smell started.
Month-by-Month: My Honest First Year
Month 1 (August): Pure Enthusiasm
Everything went in. Vegetable scraps, fruit peels, coffee grounds with the paper filter, eggshells, dead flowers from the balcony. I was diligent about adding brown material — cardboard torn into strips, dried leaves, newspaper. The ratio guides say roughly 3:1 browns to greens by volume. I was doing maybe 2:1 because the kitchen scraps accumulated faster than my cardboard supply.
The composter sat in dappled shade against the back fence. Temperature inside: warm to the touch when I lifted the lid. Everything seemed fine. I turned the contents once a week with a pitchfork I bought for €15 at Tokmanni. I told everyone about my composter. My neighbors nodded politely.
Month 2 (September): Still Fine, Slightly Concerned
The volume in the bin had reduced by about a third, which was exciting — decomposition was happening! But I noticed the newer material on top wasn’t breaking down as fast. The banana peels I’d added a week ago still looked like banana peels. I started cutting scraps smaller before adding them. Big difference. A halved avocado skin takes months. The same skin cut into 3cm pieces disappears in weeks.
I also made my first mistake: I added a large amount of cooked rice after cleaning out the fridge. Cooked grain in a composter is technically fine, but a thick layer of it compacts and goes anaerobic, which creates exactly the kind of smell you don’t want.
Month 3 (October): The Smell
That rice, combined with me falling behind on brown materials as autumn progressed and I ran out of stored leaves, created a wet, dense layer in the middle of the bin that smelled like… well, imagine a gym bag left in a car for a week. Sour, sharp, wrong. My neighbor — the one who’d been politely nodding — mentioned it.
The fix was simple but labor-intensive: I opened the bin, broke up the matted layer with the pitchfork, mixed in a massive amount of dry brown material (I bought a bale of straw from Plantagen for about €8), and left the lid slightly ajar for a day to let air in. Within three days, the smell was gone. The lesson was clear: compost needs air and it needs balance. Too much wet green material without enough dry brown material creates anaerobic conditions that stink.
Months 4-6 (November-January): The Deep Freeze
This is where Finnish composting gets interesting. By mid-November, overnight temperatures dropped below zero consistently. By December, the contents of my composter were frozen solid. A complete block of ice, food scraps, and cardboard. I couldn’t turn it if I tried.
I kept adding kitchen scraps on top — they froze within hours, building up like geological strata. Some composting guides suggest stopping additions in winter. I disagree, at least for the Kekkilä model. The frozen material thaws in spring and decomposes rapidly as the microbes reawaken. It’s like pressing pause, not stop.
The one adjustment I made: I kept a small covered bucket (a Kekkilä kitchen compost bin, about €18) on the kitchen counter and only made the trek to the outdoor composter every 3-4 days instead of daily. Nobody wants to walk to the back garden in -18°C every evening. The bucket holds about 4 liters and doesn’t smell if you empty it regularly and keep the lid on.
January was the quiet month. The composter was a frozen dark green lump under snow. I barely thought about it. This, I’ve since learned, is the natural rhythm of Nordic composting: intense activity from May to October, pause from November to March.
Month 7 (February): Small Signs of Life
A warm spell in late February — around +2°C for a few days, which passes for warm here — caused the top layer to soften slightly. I could see the frozen banana peels from November starting to look mushy rather than solid. Nothing was actually composting yet, but the thaw was beginning. I added extra brown material on top (shredded newspaper) to absorb the moisture I knew would come as everything melted.
Months 8-9 (March-April): The Spring Thaw Explosion
This is the dramatic part. Between mid-March and late April, as temperatures climbed above 5°C consistently, everything that had frozen over winter began thawing and composting simultaneously. The bin went from frozen solid to warm in about three weeks. I could see steam rising from the contents on cool mornings. The microbial activity was intense — the center of the pile reached roughly 50-60°C according to the compost thermometer I’d optimistically bought back in August (a Kekkilä model, about €14, basically a long metal probe with a dial).
This is when I turned the compost every 4-5 days. The material reduced in volume dramatically. What had been a full bin of frozen layers compacted and broke down into maybe 40% of its volume. It started looking less like identifiable food scraps and more like dark, crumbly earth. The smell shifted too — from nothing (frozen) to a rich, forest-floor earthiness. No trace of the October incident.
Month 10 (May): First Harvest Attempt
By mid-May, I was convinced the bottom layer — the material from August through October of the previous year — should be ready. I opened the bottom hatch of the Kekkilä composter and pulled out a shovelful.
It was… mostly done. Maybe 80% finished compost, with some stubborn items mixed in: eggshell fragments (these take ages), avocado pits (I don’t add those anymore), and a few pieces of cardboard that hadn’t fully broken down. I sieved it through a piece of chicken wire I’d bent into a rough frame over a wheelbarrow. What passed through was beautiful — dark brown, crumbly, smelling of earth. About 15 liters of usable compost from the bottom layer.
Not a lot for a year of effort. But genuinely satisfying in a way I didn’t expect.
Months 11-12 (June-July): The System Works
By summer, I had a rhythm. Kitchen scraps went in every few days. I added brown material every time — I keep a bag of dried leaves and shredded cardboard next to the composter so there’s no excuse. I turned the contents weekly. The spring-added material was composting fast in the summer heat.
By July, I harvested another 20 liters of finished compost from the bottom. I mixed it into my container garden planters as a top dressing. The plants responded noticeably — the Miscanthus put out new growth that was visibly greener, and the Heuchera that had been limping along suddenly looked lush. Home-grown compost has a richness that bagged stuff from the garden center doesn’t match. More microbial diversity, more trace minerals, more life in it.
What to Compost (And What to Keep Out)
After twelve months of experimentation, here’s my actual list:
Green Materials (Nitrogen-Rich)
- Vegetable and fruit scraps (cut small — 3cm or less breaks down fastest)
- Coffee grounds with paper filters (the number one item in my bin by volume)
- Tea bags (check they’re not plastic-lined — most Finnish brands are fine)
- Fresh grass clippings in thin layers (never dump a thick mass)
- Soft garden waste — dead flower heads, plant trimmings
- Eggshells (crush them small, they break down slowly but add calcium)
Brown Materials (Carbon-Rich)
- Cardboard torn into strips (cereal boxes, egg cartons, delivery packaging)
- Newspaper (shredded, not glossy inserts)
- Dried autumn leaves (I collect bags of these every October — liquid gold for composting)
- Straw or hay
- Sawdust in small amounts (untreated wood only)
- Paper towels and napkins (unbleached preferred)
What I Don’t Add
- Meat, fish, or dairy: Can compost in industrial systems, but in a home bin they attract rodents and create genuinely horrible smells. My one experiment with fish skin in month two confirmed this. Never again.
- Cooked food with oils or sauces: The oils slow decomposition and attract pests.
- Dog or cat waste: Disease risk. No.
- Diseased plant material: You risk spreading pathogens back into your garden when you use the compost.
- Glossy or colored cardboard: Chemical inks and coatings don’t belong in your soil.
- Avocado pits: Technically compostable. Practically, they sit in there for a year looking exactly the same. I gave up.
- Citrus peels in large quantities: A few orange peels are fine. A bag full of clementine skins from Christmas makes the bin too acidic. I add them gradually throughout winter instead of all at once.
The Brown-to-Green Ratio: The Single Most Important Thing
If you take one thing from this entire post, make it this: maintain roughly a 3:1 ratio of brown to green material by volume. Every time you add a kitchen container of green scraps, add about three times that volume of brown material. Torn cardboard, dried leaves, newspaper strips.
When the ratio is right, the compost smells like earth. When it’s wrong — too much green — it smells like garbage. When it’s too brown, nothing happens and the pile just sits there being dry and inert.
I keep a dedicated bag of “browns” next to the composter. In autumn I fill several garbage bags with fallen leaves and store them in the shed. This stash lasts me through spring. Once the leaves run out, shredded cardboard takes over as my primary brown source. Amazon deliveries finally serve a purpose beyond the initial package.
Finnish Composting Regulations: The Bureaucratic Part
If you’re composting in Finland and you live in an apartment building or housing cooperative, there are rules. The composting regulations (jätehuoltomääräykset) vary by municipality but generally require:
- Notification to the housing association (taloyhtiö) board before placing a composter on shared property.
- An insulated, rodent-proof composter for food waste. The Kekkilä 230L meets this standard. Cheaper open compost bins typically don’t qualify for food waste — they’re fine for garden waste only.
- Location requirements: Usually at least 8 meters from the nearest window and not directly against the building wall. My bin is about 10m from the nearest apartment window, against the back fence. Check your local rules — Helsinki, Espoo, and Vantaa all have slightly different distances.
Our housing association approved my composting request at the next board meeting. The one condition was that I be responsible for maintenance and that the bin not create odor problems for other residents. After the October incident, I’ve been paranoid about keeping the balance right. No complaints since.
If you’re in a house with your own yard, the regulations are lighter — generally just the distance-from-neighbor requirements. A couple in Lauttasaari I know have two composters and a worm bin running with no issues.
Dealing With Problems
It Smells Bad
Too wet, too much green material, not enough air. Fix: add a large amount of dry brown material, turn the pile, ensure air can circulate. Works within 2-3 days.
Nothing Is Happening
Too dry, too much brown material, or it’s frozen (in which case, wait for spring). Fix: add water and green material, turn the pile. In summer, a stagnant pile usually needs moisture — I pour a watering can of water through it if the contents feel dry and papery.
Fruit Flies
Annoying but harmless. They appear in summer when fruit scraps sit on the surface. Fix: always bury fresh green material under a layer of browns. I keep a 5cm layer of dry leaves on top at all times, which eliminates the problem almost entirely.
Rodents
I haven’t had this problem because the Kekkilä composter is solid plastic with no ground-level entry points. But neighbors who use open pallet composters for food waste have had mice and once a rat. If rodents are a concern, a closed bin with a solid base is non-negotiable. Hardware cloth (6mm mesh) under an open-bottom bin also works.
What I’d Tell Myself at the Start
Don’t overthink it. Composting is decomposition, which is the most natural process on earth. You’re not inventing anything. You’re just creating the conditions for biology to do its thing. Too much internet research before starting almost stopped me — the forums are full of people debating carbon-to-nitrogen ratios to decimal points and insisting on specific layering techniques. Just throw in roughly three parts brown to one part green, keep it moist but not wet, turn it occasionally, and wait.
Start in spring or summer, not autumn. I started in August, which was fine but meant my compost went into freeze mode just as it was getting going. Starting in April or May gives you a full growing season of active decomposition before winter.
Coffee grounds are your friend but not your only friend. Finnish composting is practically synonymous with coffee grounds because we drink more coffee per capita than almost any country on earth. My bin was easily 30% coffee grounds by volume in the first months. This isn’t ideal — coffee grounds are fine as a component but they’re quite acidic and quite dense. Mix them with plenty of lighter browns and other green material.
The finished compost is remarkably satisfying. I was surprised by how good it felt to spread my own compost around my container plants and watch them respond. There’s a direct connection between yesterday’s lunch scraps and today’s garden growth that feels almost primitive in its simplicity. In a world of complexity, compost is reassuringly straightforward.
The Bigger Picture
Composting connects to everything else I try to do at home. The compost feeds the containers on the terrace. The terrace plants produce dead foliage that goes back into the composter. The kitchen generates scraps that fuel the cycle. It’s a loop, and once you see it working, every banana peel that goes into the regular trash bin feels like a small loss.
Helsinki’s municipal composting and biowaste collection system is good — better than most cities. But home composting produces a superior end product (because you control what goes in), reduces the energy spent collecting and processing biowaste, and gives you genuinely useful garden material for free. The Kekkilä bin will pay for itself in about two years compared to buying bagged compost from Plantagen at €5-7 per 40-liter bag.
The smell, by the way, never came back after that October incident. My neighbor — the one who mentioned it — asked me about starting her own bin in January. She set hers up in March. I consider this a successful conversion. We now exchange brown materials and composting observations over the back fence like the world’s most niche hobbyists.
And the compost itself? That dark, crumbly, earth-smelling material that I harvested last May and mixed into my planters? It’s currently helping feed a Miscanthus that reaches almost to my shoulder, Heuchera that’s never looked better, and a container of herbs by the kitchen door that actually survived more than six weeks this year. Full circle. The kind of thing that makes you unreasonably happy on a Tuesday morning when you’re standing on the terrace with coffee, looking at plants that are thriving on last year’s vegetable peels.
Some things in life are supposed to be that simple.
