What’s the Big Deal With Acidity and Coffee?
If you’re serious about your coffee, you may have heard varying opinions regarding acidity levels in coffee. First things first, of the roughly 1000 different chemical compounds identified in coffee, nearly 50 are acids. As green coffee beans undergo chemical reactions in the roasting process, the levels and concentrations of certain acids change. In general, the process of roasting coffee beans attempts to bring out the best balance of these natural acids found in the particular variety of coffee
While some acids do not survive the roasting process of the coffee bean, the most perceivable acids that endure give the coffee variety its unique characteristics. A few of the more common natural acids detected after roasting are:
- Chlorogenic acids or CGAs that determine a coffee’s perceptible acidity. Meaning, as they are found to degrade rapidly during roasting, high levels of CGAs are typically found more in a “bright” and “acidic” light roast rather than darker or longer roasted coffee.
- Citric acid is often detected with a fresh coffee crop and features notes of lemon and orange (more commonly in Arabica coffee).
- Phosphoric acid is sweeter than most other acids and usually detectable as a less sour, grapefruit note.
- Malic acid commonly tastes of apple or pear and is a result of extreme temperature deviations between day and night in sun grown coffee farms.
- Acetic acid (the acid detectable in vinegar) is unpleasant in higher levels and usually reveals that the coffee was not properly processed. This could be due to the beans sitting in a fermentation tank too long or the beans being roasted at too high temperature.
- Quinic acid is the product of other acids degrading. High concentrations of this acid are common in dark roasts, stale brewed coffee, and brewed coffee kept warm on a hot plate.
As you may have already tasted, roast level is largely a personal preference. In a nutshell, lighter roasts are higher in acid and considered more bright tasting, while medium and dark roasts balance acid with body. Typically, coffee aficionados lean towards the lower acidity of medium and dark roasts as it’s found that higher acidity in coffee actually anesthetizes the tongue. This prevents the taster from detecting the unique characteristics and subtle nuances of flavours (fruits, chocolate, nuts) of the particular coffee variety.
At Frog Friendly Wild Coffee, we proudly offer a low acidity Medium and Dark Roast of our Arabica (variety of coffee) beans grown in the unique cloud forests of the Oaxaca region of Mexico and craft roasted in Canoe, British Columbia.