Small scale composting in Singapore

Small scale composting in Singapore
My compost bin.

I've been experimenting with composting recently, and pleasantly surprised by the results. It was way, way easier and faster than I thought it would be. In Singapore's climate, the heat and humidity causes food to break down quickly, and I didn't have to maintain the compost much after I got it going.

Why compost?

I started experimenting with compost because of a few reasons:

  1. I've started to grow plants and I don't want to keep buying soil from the store.
  2. Food waste tends to take more energy to incinerate due to the high water content. So I wanted to do something else with it.
  3. It is one of the last few habit changes I have yet to make to lower my carbon footprint.
  4. I've never tried it before.

Compared to the other lifestyle changes outlined in my other post, composting is much lower on the list. So this is more for fun than anything else.

How to compost on your balcony

Choosing a container

Any container will do, as long as there are holes to allow air to flow. I prefer to have a cover as well to protect it from the rain.

As you can see in the picture above, I've relied mostly on leftover items - an egg tray cover to catch stuff coming out in the base, and extra fridge components for the container itself. I drilled holes into the bottom and sides of my container. I opted not to drill holes into the cover since it was well aerated on the sides and bottom.

With this size of container, it was enough to process about 4-5 days' worth of vegetable scraps and egg shells for 1 person's consumption. Since my household tends to batch cook, all these scraps goes in all at once when we're done with cooking for the day.

Starting ingredients

Compost ingredients are separated into two types - greens and browns. You'd generally want a ratio of 1:2 greens to browns (I eyeball this usually), though you can go up to 1:1 ratio.

For the browns, I think it's best to start off with some ready-made compost. I bought a bag of compost from the store (about 5 litres). I also added other dry items like newspapers, cardboard eggshell cartons, paper bags and dried fallen leaves from my plants.

For the greens, I started with vegetable scraps like carrot peels, potato peels and apple skin. I also put in clam shells that I hammered into smaller pieces. I also added some dead insects I found.

Preparing the bin

  1. Line the bin with old newspaper. This was to catch any soil that might fall out from the holes.
  2. Add a layer of browns about 2 inches.
  3. Alternate green and brown layers (about 2 inches each), ending with a brown layer on top. At my scale, I only had 1 layer of greens total.

Bin maintenance

I turn the bin about once every week to mix up the ingredients and check the progress. Each time after I turn, I add more brown material on top to cover any new exposed green material (or remove some of the top layer to cover it back later). By the first week, most of the peels were gone; only the clam shells and tougher peels (like potato peels and onion skin) still remain. I only add new green material once most of it is gone; since the bin is small, I make sure not to overload it. For extra green material, I keep it in the freezer until the bin can take more green material, which is once every 1-2 weeks.

How much waste can you avoid?

At this point, unfortunately not all of my food waste can be composted; the bin is simply too small to accommodate. I'd say it takes up to between 50% - 70% of my waste.

Will my compost bin smell?

If all goes well, your compost bin should just smell like soil (or a rainforest). I usually don't add water to my compost bin, so it's a little bit dry, but I prefer it that way, since I'd rather have the process go slowly than have the compost go bad.

One thing apart from the water content that can cause it to smell is meats or dairy content. I will experiment with meat leftovers in the future cautiously; I will probably freeze them first to get rid of any eggs that may be in there, and bury them very well.

What do I do if the compost attracts insects?

I've had some fruit flies and fungus gnats in the compost. I've also seen some crawling insects in the compost as well. I've come to see them as normal; after all, they help to speed up the composting process, and don't come into the house. I got rid of the fruit flies by setting out an apple cider vinegar trap. I put out some apple cider vinegar and some soap in a container with holes on the lid, and many of them flew into the trap and died.

Burying the food scraps with extra brown material seems to help, but the insects don't fully go away (I'm skimping a bit on the soil used here). If you use more brown material like soil to bury the food scraps, it should work.