Food Composting 101

Food waste makes up to 40% of solid wastes generated daily in Penang which is equivalent to an estimated 700,000kg!! That is a LOT. Some of the food waste can be composted instead of tossing it away into the bin. Composting is a natural process of decomposition which later turns organic materials like vegetable food scraps and garden waste into a dark, crumbly and earthy smelling substance called compost.



But before we go deeper, we should understand the benefits of composting. Composting helps to divert as much as 30% of household waste from the trash bin especially organic matters which require air for natural decomposition. When organic matters reach the landfill, it creates harmful methane gas as it breaks down thus results in an increase of global warming and climate change. Compost is rich in nutrients and great for the garden or even indoor potted plants. It’s a simple way to add nutrients that nourish the plants and restore vitality to depleted soil.


Now that we already know the benefits, let’s move on to the basics – what you can & cannot compost. The basic needs for all composting includes 3 main ingredients: Browns (carbon), Greens (nitrogen), Water (moisture).


Browns: Twigs, branches and dead leaves

Greens: Vegetable waste, fruit scraps, coffee grounds, grass clippings


To make it simpler, let’s refer to the table below:

There are 3 kinds of composting methods: aerobic, anaerobic, and vermicomposting.

a) Aerobic – Use air to help break down materials quickly. The compost needs to be turned in every few days to keep it aerated hence is more suitable for outdoor composting. This method requires you to add more greens to your compost to speed up the process. Don’t forget to keep an eye on the moisture level to prevent odours.


b) Anaerobic – It is the opposite of the aerobic method where it requires almost no effort at all. However, hold your nose as it can get very stinky! Without the oxygen, nasty bacteria will take over and this is what happens to the landfill as we speak. Landfills produce so much methane gas which is very harmful to the environment. You might want to reconsider this method.


c) Vermicomposting – Uses worm, oxygen, and moisture with minimal odours. Worms will do most of the heavy work aided by the bacteria. The most common worms used are red worms and this method is more preferable compared to the other two because it doesn’t smell bad but more ‘earthy’, there is no need to “turn” the composter frequently and can be used for both indoor & outdoor. If you like to go fishing, it’s a plus point as you will get an endless supply of bait from your composter.


How to Compose at Home?

1. Backyard Composting

· Select dry, shady spot near the water source. Add in brown & green materials, make sure to chop or shred larger pieces.

· Moisten the dry materials as you add. Mix grass clippings and green waste to the pile & bury the vegetable/fruit waste under 10 inches of the compost pile.

· You can cover the top to keep the moisture. You know it’s ready when the compost looks dark and rich in colour at the bottom.


2. Indoor Composting

· If you do not have space for an outdoor compost pile, you can make the compost using a special type of bin which you can find in the local hardware or gardening store. However, you need to keep track of what you throw into as a poorly managed pile will smell bad & attract rodents and pests to your home.


Happy Composting!