It was a long, cold winter in the Northeast, but after several months of my compost just freezing in situ over the last 30 days or so, my food and other biodegradable materials have been breaking down again and I have a serious pile of dark brown soil to throw in my garden beds! Part of that compost is made up of materials I have tested out for this column - plenty of Whole Foods takeaway containers, Bambu plates, and more - but unfortunately, a corn cup I used for wine at a party last August has not found the same end. After seven-plus months in my compost heap (with a few of those months frozen solid, I'll admit!), it has not biodegraded one bit, which was a disappointment after my previous successes. When I did some checking, I found that the cup, which is made from corn, is only meant to degrade in a commercial compost system.
The corn cup, moments before I took it out to compost.
I went to the website for the cups, which are made by Natureworks, and my initial frustration with the fact that the cup hadn’t broken down was allayed a bit by what is clearly quite a bit of thinking about how to make a sustainable, disposable product (hmm, I wish that was actually an oxymoron in our society).
But should we be using foods — which could be eaten by hungry people or even less hungry but still food-creating cows — to make packaging (or even fuel), considering the energy needed to grow those crops (mostly petroleum-based energy) in the first place? It seems wasteful, and that there should be a better way, so I did some digging: how green are these cups really?
Personally I think this is a great start to alternatives for actual plastic cups. If we support the industry behind these new developments, they will get better with time! Now we just need more commercial composting systems!
All of these compostable plastics are heat triggered. Most people who “compost” at home are not really composting, which requires lots and lots of turning in order to get the heat up to 145F to 155F for 15 or more days. At about 140F these containers break down.
I did not see in the article whether the containers were made with non-GMO corn or not. Good luck finding these corn-based plastics made with certified organic corn.
It is best to stick to reusable bottles and utensils or paper products.
I hate these cups! Most of the time they end up in the recycling bins, so they end up getting mixed with all the regular plastics… Then they dilute the recycled product and make it unusable. If you need to use disposable cups, use either real plastic and recycle or use paper cups!