Modern chemists recognize two classes of ferments:
A. Organized ferments, which are living vegetable organisms; such as, the yeast plant and other microscopic fungi.
B. Unorganized or chemical ferments, that consist of certain compounds of organic origin; such as, "diastase", "pepsin", etc.; which is now replaced in scientific use by "enzymes" or proteins produced by living organisms and functioning as biochemical catalysts or substances that modify and increase the rate of a reaction without being consumed in the process.
2. To seethe or to be disturbed by social agitation or excitement in order to promote changes: Demonstrations by union workers fermented when the company decided to reduce the number of employees, including Sharon's husband.
When a certain politician was caught taking part in drugs, the legislative members were fermenting to get him to quit and when that didn't work, they voted to reduce his power of office.
3. Etymology: from Latin, "leaven or yeast"; generally an agent that causes fermenting.In order to foment a revolt among the farm hands, the revolutionary forces spread lies which caused a state of ferment among the farmers.
They even went to the local pub and ordered beer which was made when the hops and barley could ferment together.