Welcome to science. these posts explore the intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment.
Since I've started keeping a five gallon compost bin, I've been noticing how less often I'm using the waste bin. In fact, right now, I'm pitching five gallons of waste once every month. I do recycle paper, plastics and glass. That goes out about twice a week and compost on average is being thrown into the larger 65 gallon bin outside every two weeks.
Compost is broken down into two categories. There is compost that is high in carbon and then there is compost that is high in nitrogen. Material that is high in carbon breaks down very slowly like dead leaves, wood, branches and cardboard. We'll categorize the material high in carbon as 'brown'.
Next, material that is high in nitrogen, like grass and lawn clippings, fruit and vegetable scraps, manure and green leafy material breaks down very quickly. We'll categorize material high in nitrogen as 'green'.
There are two methods to composting. Our building uses a method called 'hot composting'. This breaks down the compost much faster into humus, the organic end product which you can use for gardening. The other method is called 'cold composting' which breaks down the compost at a much slower pace. In the hot composting method, we use a carbon/nitrogen ratio in volume. So for every one bucket of green, we add two buckets of brown.
Have you ever noticed the heat that is generating inside either your kitchen trash or compost bin? What's happening is the mesophilic phase of decomposition. Microorganisms are rapidly breaking down the soluble, degradable compounds in your compost and in the process, a bi-product of heat up to 113°F is created. After a few days, heat loving bacteria in the thermophilic stage take over with temperatures ranging from 106°F to 252°F and lasts from weeks to months depending on what type of compost method you are using. Higher temperatures of the thermophilic stage will be seen more in the larger compost bin outside. In this stage, the microorganisms are breaking down proteins, fats and complex carbohydrates. As this happens, the total mass of the compost decreases. In essence, your compost is breaking down everyday in your kitchen (and outside in the larger bin). If your compost wasn't breaking down, you'd be dumping your compost a few or more times a week. I dump my compost about every two weeks. So technically, I add more mass in my kitchen than I dump out. See the chart below.
Once your compost is moved outside, the temperatures will continue to rise to over 150°F if you don't aerate it. Aerating adds oxygen to the compost helps with decomposition. Otherwise, the hotter it gets, the more likely it is to kill off the bacteria and slow down the decomposition process. Once the energy compounds are exhausted and the temperature cools off, the mesophilic microorganisms take over again and thus begins the maturation phase that breaks it down into its final form: rich humus, the end product.
Now back to my trash can. I'm replacing it with a one gallon can with the goal of reducing my total waste to 1/2 gallon every month. And instead of throwing my trash can away, I'm giving it to someone else who needs one. It is plastic after-all and I don't want it to end up in a land fill.
I will continue to do tests on composting in-take and out-take as well as monitor total waste out-take and will update these statistics periodically.