Have you ever heard someone describing a cup of coffee as having “a fine bouquet”? Did you think they had somehow confused their morning caffeine with fine wine? They weren’t wrong to consider their coffee that way.
Coffee and cacao beans are fermented. Similar to wine, the flavor of the beans is determined by the type of yeasts and microorganisms present. A common misconception that all the beans’ flavor comes from the roasting process.
Cacao pods are fermented five to seven days. Yeasts and bacteria digest the pulp surrounding the beans and trigger biochemical changes that color and flavor the beans. Coffee growers use different types of fermentation.
Some use a two‑day wet fermentation to remove the red pulp from the bean, while others use dry methods that require several days. After fermentation, the beans are roasted.
[pullquote] The flavor of coffee beans is determined by the type of yeasts and microorganisms present.[/pullquote]
If you know something about the wine making process, you know that winemakers use special yeast to create wine. Scientists wondered if the same techniques could be applied to the coffee bean fermentation process.
They also wondered because wild yeasts and microbes were originally used to ferment both beans if they could identify the yeasts being used and where they originated. Those scientists collected unroasted coffee and cacao beans from twenty-seven countries.
They isolated bean yeasts and analyzed their genes. The yeasts are diverse, but most strains from the same continents and countries are similar to their immediate neighbors.
Still, some cacao strains from South America share genes with European vineyard yeast and North American oak tree yeast, and are probably the result of human trade. With a good batch of beans, the yeasts and fermentation process do add to the flavor.
- “Independent Origins of Yeast Associated with Coffee and Cacao Fermentation” by Catherine L. Ludlow, et al.
- “The Rise of Coffee” by Fernando E. Vega