1. Classical (Microbiological) Fermentation:
This is the most common definition, especially in biology and food science:
Fermentation is the metabolic process by which microorganisms (like bacteria or yeast) convert organic compounds—typically sugars—into other substances such as alcohol, acids, or gases.
Examples:
Yeast turning sugar into alcohol in beer or wine.
Lactic acid bacteria fermenting lactose in yogurt.
2. Enzymatic (Non-Microbial) Fermentation:
In certain fields, especially tea processing, cigar aging, or cocoa fermentation, the term fermentation is also used more broadly to describe biochemical changes driven by enzymes—either from the plant itself or from microorganisms.
Examples:
Tea (e.g., black tea): The so-called "fermentation" is actually oxidation catalyzed by enzymes in the tea leaves themselves (like polyphenol oxidase), with little to no microbial activity.
Cigars (tobacco leaves): Enzymes within the tobacco leaf, often activated by warmth and moisture, cause internal biochemical transformations (not always microbial).
Cocoa beans: Initially microbial fermentation, but internal enzymes in the bean also break down compounds, affecting flavor.
Fermentation is the metabolic process by which microorganisms (like bacteria or yeast) convert organic compounds—typically sugars—into other substances such as alcohol, acids, or gases.
Examples:
Yeast turning sugar into alcohol in beer or wine.
Lactic acid bacteria fermenting lactose in yogurt.
2. Enzymatic (Non-Microbial) Fermentation: In certain fields, especially tea processing, cigar aging, or cocoa fermentation, the term fermentation is also used more broadly to describe biochemical changes driven by enzymes—either from the plant itself or from microorganisms.
Examples: Tea (e.g., black tea): The so-called "fermentation" is actually oxidation catalyzed by enzymes in the tea leaves themselves (like polyphenol oxidase), with little to no microbial activity.
Cigars (tobacco leaves): Enzymes within the tobacco leaf, often activated by warmth and moisture, cause internal biochemical transformations (not always microbial).
Cocoa beans: Initially microbial fermentation, but internal enzymes in the bean also break down compounds, affecting flavor.