Experiment Originally uploaded by piroko_kuroda We watched a TV show this morning, and it made us to have an experiment on konnyaku this afternoon with Mo. It's made from yam, called elephant foot or devil's tongue in English (really?), which academic name is Amorphophallus konjac. Grated yam mixed with calcium hydroxide ( Ca(OH) 2) causes glucomannan, which is a kind of polysaccharide, to gelatinize. So, boil konnyaku with brown skin of onion, it supposedly turn into red. Boiling with gobo (burdock root) makes konnyaku turn into green. We used regular gray ball ones, though we're supposed to use white ones, because we couldn't find them. Anyhow, do you see the color? It's dark green and dark red/orange. If you boil it with grape juice it will be purple and hibiscus tea will make it red. Well, it was an interesting experiment.