Western Terrain Coffee RoastersFiguring out the chemistry underlying a delicious cup of coffee has been our top priority since we mastered sliced bread. If you’re a coffee enthusiast, you undoubtedly already know that not all coffee is created equal and that two cups are rarely identical.
How can two cups be so dissimilar? Coffee is the same, but each brew can produce wholly different experiences. So why is it so tough? Why? Because there is a great deal of sophisticated chemistry involved!
We all know and enjoy coffee for its caffeine content, however caffeine has no effect on the flavour of coffee. Excellent roasting, beans, and brewing are required to produce a delicious cup of coffee. Let’s look at the chemistry of coffee.
The Chemistry of Coffee: The Components
The ordinary cup of coffee includes more than a thousand compounds, and while scientists have not identified all of them, they have identified the most important ones in terms of flavour and potential health advantages.
Caffeine
Caffeine is a psychoactive substance used by millions of individuals throughout the world due to the widespread use of coffee. YES, caffeine is a drug!
Caffeine reduces weariness, improves perception, and gives you that additional jolt to help you stay awake; some studies suggest that it may also improve long-term memory.
In addition to promoting wakefulness and alertness, caffeine is associated with increased energy expenditure and metabolism. Dietary standards advise that up to 400 mg of caffeine per day is OK when it comes to coffee consumption.
Trigonelline This bitter-tasting alkaloid has been found to prevent the spread of cancer cells, protect the brain, reduce total cholesterol and blood sugar levels, and fight microorganisms.
These Chlorogenic Acids
Approximately 45 phenolic compounds have been identified in coffee. These chemicals, together with their breakdown product caffeic acid (1), have been found to have anti-inflammatory and antibacterial characteristics, assist reduce type-2 diabetes, and aid in the prevention of cardiovascular disease.
Cafestol and Kahweol
These diterpenes (2) are responsible for your coffee’s bitter flavour. These substances have been demonstrated to prevent and combat cancer. The bad news is that they are also connected to cholesterol elevation.
Coffee beans maturing at various phases
The Secret Behind Delicious Coffee
Now that you have a better knowledge of the components found in coffee, let’s examine the beans, the roast, and how to brew a delicious cup.
The Bean Coffee growers invest a great deal of time and effort into producing and harvesting coffee trees (yes, coffee does grow on trees) in order to provide you with the perfect cup of joe. In case you were unaware, the coffee bean is the pit of a cherry. After the coffee bean has been extracted from the cherry, it is dried and processed.
Arabica beans (Coffea Arabica) and Robusta beans are the two most prevalent commercially viable coffee bean varietals (Coffea canephora var. Robusta). However, there are over 70 species of Coffea (plants that produce coffee beans), but the vast majority are not edible.
Choose Arabica beans for the best-tasting coffee since they have a greater diversity of fragrances and more balanced flavours. Additionally, Arabica beans typically contain higher trigonelline and diterpenes (kahweol and cafestol).
Coffee Roasting Equipment
Robusta beans contain about twice as much caffeine and chlorogenic acids than Arabica beans, but their flavour is typically more harsh.
The Cooking
During the roasting process, green coffee beans are transformed into wonderful, toasted brown beans. Additionally, roasting helps bring out flavours such as floral notes, chocolate, and more.
There is no uniform process used by all coffee roasters to roast coffee beans. However, coffee beans are commonly roasted in a multi-step procedure ranging from 150 to 250 degrees Celsius and 2 to 25 minutes.
150 to 200 Degrees Celsius
At around 150 to 200 degrees Celsius, the Maillard Reaction (3) occurs during the initial phase. During this reaction, proteins and carbohydrates combine to generate fragrance and flavour molecules. Maillard chemistry is not exclusive to coffee; it also contributes to the superb browning, flavour, and aroma of dishes such as fries, steak, and, of course, bacon (…mmm bacon).
The Maillard process also contributes to the formation of numerous other chemicals, such as 2-furfurylthiol (4), which gives roasted coffee its exquisite flavour.
170 to 200 Degrees Celsius
As the temperature slowly climbs to between 179 and 200 degrees Celsius, caramelization begins, the natural sugars caramelise, and the resulting molecules provide burnt sugar (furanones) and butterscotch (diacetyl) flavours.
At 205 Degrees Celsius
When the temperature reaches 205 degrees Celsius, the water within the bean begins to evaporate, causing it to expand and eventually crack open. This is referred to as the “first crack” in the world of coffee.
“Light roast” coffees are taken from the roaster at the first crack. Light roasts are typically more acidic, and the peculiarities of various bean origins are most apparent in light roasts.
225 to 230 Degrees Celsius
The second crack occurs as the beans continue to roast and the temperature reaches 225 to 230 degrees Celsius.
This second fracture is caused by the cellulose in the cell walls of the coffee bean disintegrating.
As the temperature rises, the bean begins to get significantly darker brown; at this point, you have the preferred medium roast. Medium roasts are well-balanced in terms of bean acidity and roasting chemistry body. Aromatic chemicals are also released, imparting coffee with an earthy aroma and roasted, earthy flavours.
Even More Heat
Any additional roasting will darken the beans and make them somewhat greasy, resulting in a dark roast. At this stage, practically all of the flavour notes will be derived from the roasting process, and it is impossible to determine the origin of the coffee bean due to the strong body. Espresso is often brewed from darker roasts.
Pouring coffee into a glass carafe.
You have a variety of coffee bean options available, but how can you create the best coffee possible?
The Ale
You’ve now reached the weakest link. You have a coffee bean with an excellent origin and a roast that you adore. All that remains is to grind it and add boiling water, correct? If if it were that simple, but you can have the world’s best coffee and still goof up this step.
There are several essential elements to creating a delicious cup of coffee. There is coffee, the water-to-coffee ratio (eschew the tablespoon in favour of a coffee scale), and water quality (forget tap water use filtered or bottled water). You have the water temperature, boiling water that is too hot will result in unpleasant burnt coffee, so it is better to have the water temperature near to 96 degrees Celsius (205 F).
Don’t forget that you must also decide how your coffee will be brewed. Pour-overs, Moka stovetop coffee makers, the Chemex, and French Press coffee makers (cafetière, press pots), to mention a few, are available, although the fundamentals of all brewing processes are same.
Chemistry Of Brewing Coffee
Now that you’ve selected the greatest coffee maker, let’s discuss coffee grind size. For the coffee grind, research indicates that the more finely the beans are ground, the more caffeine you will extract from them.
In one study (5), researchers discovered that grinding a 37-gram chunk of coffee for 42 seconds as opposed to 5 seconds increased the quantity of caffeine extracted.
Another study (6) indicated that the presence of more particles (the fine powder that transforms into coffee sludge) contributed to the overall rise in caffeine concentration.
Hario V60 coffee dripper
When water is added to ground coffee, the water spreads throughout the grounds and CO2 begins to bubble out; this is known as the “coffee bloom.” Once the grounds are completely saturated, the hot water will begin to dissolve the chemicals present in the roasted coffee bean cells.
Most of the tasty compounds will dissolve in water more quickly than the undesirable ones, so be sure to add enough water to dissolve the tasty compounds without diluting the coffee’s flavour.
Eventually, osmosis will begin to pull these chemicals out of the coffee grinds and into the water, delivering all of these wonderful flavours into your coffee pot.
Coffee enthusiasts will tell you that manual pour-over coffee brewing methods, such as the Chemex and Hario V60, are superior to automatic coffee machines. This is true while manually brewing coffee. You have far greater control over the brewing procedure and can make adjustments on the fly, like as when water is added.
In addition, pour-over systems continuously supply the coffee grounds with fresher water, which speeds up the brewing process. The water is manually poured in a single stream, as opposed to the showerhead-like device seen on automatic drip coffee makers.