Coffee is prepared from roasted coffee beans which are seeds of the berries from the Coffea plant. The berry is now cultivated from over 70 countries around the world, with the primary exporters being the Americas, Southeast Asia, India and Africa.
Similar to chocolate, coffee under goes great flavour changes while the bean is being roasted. There have been over 850 aroma/flavour compounds which have been discovered in coffee and this number only continues to climb. Coffee flavour is complex and might contain flavour notes of black current, coriander seed, clove, vanilla and chocolate.
Aroma
Waking up in the morning and appreciating the smell of freshly-brewed coffee is one of life’s greatest pleasures. This is a result of the vast collection of volatile compounds found in the aroma of brewed coffee. Aroma may be perceived by either the nasals when you smell the coffee or retronasally. When you take a drink of coffee, volatile compounds may drift upwards into the nasal passage; this is known as retronasal perception.
There are multiple chemical processes which affect the development of the volatile compounds in the coffee. Some examples include:
- Degradation of sugar
- Maillard or non-enzymatic browning
- The environment the beans are grown in
- Processing and roasting
Acidity
The acidity of coffee can be attributed to the processing, variety, roast, variety and altitude it was grown. Washed processed coffees tend to have a greater amount of acidity when compared to naturally processed coffees. Darker roast coffees typically have lower acidity when compared to light roast. Coffees which are grown at higher altitudes and in mineral rich volcanic soils also tend to have higher acidity.
The regions of Central American and some of East African coffee believe that acidity is an important characteristic. However, it is important to note that too much acidity can be perceived as sour and be considered a defect.
If you wish to describe the acidity of your coffee try using some of these descriptors:
- Mellow
- Winey
- Citrus
- Sour
- Berry-like
Body (viscosity)
The body of brewed coffee is just as important as the aroma during consumption. The viscosity of coffee is dependent on the brewing method such as French Press or Coffee Machine Brew. Factors such as roast, processing and terrior also play a role in the body.
The body of a cup of coffee can be described based on how thick it is perceived. When you drink something which is heavier it is viewed as fuller or thicker.
- Light Body: watery, tea-like, silky, slick, juicy
- Medium Body: smooth, milky, syrupy, round, creamy.
- Heavy Body: full, velvety, big, chewy, coating.
The Main Compounds Which Determine Coffee Flavour
Due to the nature of coffee, each cup may be different from the other. However, there are four main groups which dominate in the description of coffee.
Coffee can be described as fruity or floral and as a result take on a crisp flavour in sweet brews or sour in less-sweet brews. These compounds are the quickest to dissolve in brewing. On the other hand coffee contains maillard compounds. These include the flavour descriptors such as toasted grain, wood and nutty. In sweeter brews the taste is malty while sharper in less sweet brews.
A caramelized flavour can be tasted in brewed coffee and is the primary source of sweetness in coffee. Darker roasts tend to have a bittersweet flavour while light roasts have a sweeter flavour. Dry distillates are a category used to describe flavours which are created the reduction of caramels and maillard compounds. Flavours such as clove and tobacco can be found in this category. Dry distillates taste dull, ashy and bitter in sweet brews and are dominant in darker roasts.
Potential Flavour Combinations
- Coffee and Hazelnuts- This combination can be found at almost every coffee shop. The nutty, roasted and toasted flavours of hazelnuts can also be found in brewed coffee.
- Coffee and Cinnamon- This may sound a quite a bit odd but cinnamon has the strength and sweetness to round out coffee flavour in baking. In Mexico it is common to find cinnamon sticks to stir your coffee
- Coffee and Avocado- Another strange pairing but this combination as a drink can be found in Indonesia. The reason why this works is because avocado and espresso both have nutty flavours. As well, avocado is creamy which helps to offset the bitterness of espresso.
References
http://www.coffeeresearch.org/science/
http://scaa.org/chronicle/2016/02/05/how-to-use-the-coffee-tasters-flavor-wheel-in-8-steps/
https://detourcoffee.com/blogs/news/118059077-the-flavour-of-coffee
