DAVIDFBT
Extinct? Since when?
It's not rotted, Yeast has been added and when yeast and sugar water meet, the yeast eats the sugar and puts out CO2 and alcohol. Most aquarists just want the CO2 for their tanks, but depending on how much sugar you added and how long you let it stand, it can either taste like a mild alcohol or something stronger than vodka. And it isn't random because we know exactly what we put in the bottle.