How to Start Composting in a Singapore Apartment
Composting in a high-rise apartment in Singapore is more practical than it sounds. The main challenge is space, not climate. Singapore's year-round warmth actually speeds up decomposition, which means a well-maintained indoor setup can process kitchen scraps faster than a similar bin in a temperate country. Below is a comparison of three methods that work inside HDB flats and condominiums, along with notes on cost, maintenance, and odour control.
Bokashi Fermentation
Bokashi uses anaerobic fermentation rather than traditional aerobic decomposition. You layer food scraps in an airtight bucket with a bran inoculated with effective microorganisms (EM). The process takes roughly two weeks inside the sealed bin, after which the fermented material can be buried in soil or added to a larger compost pile.
A standard dual-bucket Bokashi set costs between S$40 and S$70 at local gardening retailers. The two-bucket system means one bin is always fermenting while the other is being filled. The liquid that drains from the bottom tap can be diluted (1:100 ratio) and used to water plants.
Smell is minimal when the lid stays sealed. If a strong rotten odour develops rather than the expected sweet-sour pickle smell, the batch has likely gone bad due to too much air exposure. Restart with a fresh layer of bran.
Vermicomposting with Red Wigglers
Vermicomposting relies on Eisenia fetida (red wiggler worms) to break down organic matter into castings, sometimes called black gold among gardening enthusiasts. A standard worm bin can be kept under the kitchen sink or in a storeroom. The worms consume roughly half their body weight in food scraps each day.
Starter kits with about 500 grams of worms cost around S$30 to S$50 from local breeders. The bin itself can be a simple stacked-tray design made from opaque plastic containers with drilled ventilation holes. Worms prefer temperatures between 20 and 30 degrees Celsius, so Singapore's indoor conditions are near ideal.
Avoid adding citrus peels, onions, garlic, and meat. These either repel the worms or attract pests. Shredded newspaper and corrugated cardboard make excellent bedding material and help absorb excess moisture.
Balcony Tumbler Composters
For residents with a covered balcony, a compact tumbler composter (around 70 to 140 litres) provides the most hands-off experience. Tumbling the barrel every two days aerates the contents and speeds up decomposition. Finished compost is typically ready in four to six weeks.
These units are pricier, ranging from S$80 to S$200, but they handle a wider variety of inputs including cooked food, small bones, and garden trimmings. The sealed drum keeps pests out and contains odour effectively. Look for models with dual chambers so you can fill one side while the other matures.
What to Compost and What to Avoid
- Good inputs: Fruit and vegetable scraps, coffee grounds, tea bags (remove staples), eggshells, rice, bread, shredded paper
- Avoid: Dairy products, large bones, cooking oil, pet waste, diseased plants
Chop scraps into pieces smaller than 5 cm to speed up breakdown. In Singapore's humidity, maintaining a balance of roughly 60% greens (nitrogen-rich wet material) to 40% browns (carbon-rich dry material) helps prevent the compost from becoming a soggy, smelly mess.
Using Finished Compost
Finished compost can be mixed into potting soil for balcony herb gardens, donated to community gardens, or offered to neighbours through local zero-waste groups. Some condominiums in Singapore have communal garden beds that accept resident-made compost, a practical way to close the nutrient loop without leaving your estate.
For official guidance on food waste reduction, see the Singapore Zero Waste Masterplan published by the Ministry of Sustainability and the Environment.