Why is my organic (kitchen) waste so heavy?
Like many cities in the developed world these days I suppose, mine has a recycling programme. Basically, organic (kitchen) waste is put out in one can once a week for composting; cans, bottles and paper in another every two weeks for recycling; garbage in a third every two weeks as well for disposal; and garden waste seasonally in paper bags. In our household, the first two are accumulated in similar sized plastic bags in containers in the kitchen and put out in the cans every once in a while, while the third is put out bagless in the third can more frequently as it accumulates. Now here is the puzzle. Whenever I happen to put out the first two at the same time, always in similarly sized bags and therefore similar in volume, the organics for composting are always, always heavier than the garbage for disposal, and by quite a lot. Every time I wonder why that is. Some possibilities might be:
- it’s just idiosyncratic to our household. I suppose if we were repairing cars and disposing of scrap metal (not that anybody would be, scrap metal is valuable these days) but if for the sake of argument we were, it would be different. But I doubt if our experience is unique (otherwise I would not be wondering about it here!)
- biological organisms need protection against antagonists, parasites and predators, hence the denser (from our point of view, waste) – thick skins, peels etc. as well as needing to reproduce – seeds etc. I doubt if that is the answer either. After all, a lot of our garbage is in fact protective – various kinds of non-recyclable packaging like the tissue thin plastic bags that bulk foods and produce are put in and some heavier packaging which have properties designed to persuade you to purchase it, i.e. to serve its reproduction.
-culturally-evolved processes have become more efficient than biologically-evolved ones. Now that is an intriguing possibility.
- finally my (originally an engineer) husband’s suggested answer is that the organic material is wet and water is heavy. Hmm – this possibility admits of an experimental answer, if we dried out a bag of organics would the weights be similar? I have never been much of an experimenter but . . .