fermentation

英[fɜːmen'teɪʃ(ə)n] 美[,fɝmɛn'teʃən]

1. a process in which an agent causes an organic substance to break down into simpler substances; especially, the anaerobic breakdown of sugar into alcohol

2. a state of agitation or turbulent change or development;

"the political ferment produced a new leadership"

"social unrest"

3. a chemical phenomenon in which an organic molecule splits into simpler substances