Coffee Chemistry

The perfect cup of coffee boils down to three factors

Coffee Bitterness

Coffee bitterness is sometimes a negative, but omnipresent aspect of the beverage.  At low levels, bitterness helps tame coffee acidity and adds another favorable dimension to the brew.  However, at high levels, a bitter coffee compound can overpower the other components present in coffee producing an undesirable effect.

Bitter coffee results from the interaction of certain compounds with the circumvallate papillae on the back of the tongue.   Astringency, on the other hand is caused by compounds that can precipitate salivary proteins on the tongue.  Consumers will often mistakenly attribute astringency and any other potent characteristic of the coffee to the bitterness.

Coffee Acidity

Coffee Acidity is the bright and dry taste that adds life and smoothness to a coffee.  Perceived acidity in coffee does not necessarily correlate to the pH of a coffee, but is believed to be the result of the acids present and akin to the dry but bright sensation experienced on the back sides of your tongue while drinking a red wine.

Acidity is unmistakable in most Kenyan coffees and should be evident in any wet-processed coffees, especially in Central American and East African coffee.  Acidity has been correlated with coffees grown at very high altitudes and in mineral rich volcanic soils.

The coffee acid content in a brew is also greatly dependent upon the coffee roasting degree, type of roaster, and coffee brewing method.  It is important to note that as the roast develops, coffee acidity decreases.  Unfortunately at darker roasts, the aroma and sweetness diminish, which is equally detrimental to the espresso.

At The Coffee Cube we do not take the common American approach of burning the life, and hence the acidity and smoothness, out of the coffee. 

We strive for a perfect balance of acidity and aroma, maintaining the integrity of the coffee irrespective of its origin.

Coffee Aroma

Coffee aroma is responsible for all coffee flavor attributes other than the mouthfeel and sweet, salt, bitter, and sour taste attributes that are perceived by the tongue.  Therefore, it might be said that coffee aroma is the most important attribute to specialty coffee.  Even instant coffee has the components responsible for stimulation of our taste buds.  The difference, however, is that instant coffee lacks most of the aromatic volatile compounds causing a dramatic decrease in the overall coffee flavor.

Coffee aroma is perceived by two different mechanisms. It can either be sensed nasally via smelling the coffee through the nose or retronasally. Retronasal perception occurs when the coffee is either present in the mouth or has been swallowed and aromatic volatile compounds drift upward into the nasal passage.