If you have never had that “How do you like your coffee?” conversation with a coffee drinker, you never know what responses you will receive:
“As dark as night, and as sweet as sin.”
“I like it very much. Thanks for asking.”
“I like my sugar with coffee and cream”
“Directly into the bloodstream, please.”
“By the gallon.”
You get the idea.
But, we have all heard someone say “I like my coffee strong” or “I like a rich full-bodied cup of coffee” or “Straight black is the only way to drink coffee”. But what do these terms really mean? Dark, strong, and rich are coffee characteristics that carry some different connotations to groups within the coffee world, just as they do in the specialty coffee circles.
What do these words mean as far as the impact it has on your coffee, and how you can alter your brewing and extraction methods to obtain the strength, mouthfeel, and flavor you desire for specialty coffees?
STRONG vs. DARK vs. RICH: DEFINED
Dark coffee means that the beans have been roasted at a higher temperature and for a longer period of time that leaves the finished coffee bean darker in appearance and gives a smoky, burnt, and bitter flavor. With dark coffee, the flavors and nuances of the coffee bean’s origin are lost and taken over by a strong roasty taste.
Rich means that the mouthfeel of the coffee is more “full” or creamy, but without adding cream or other thickening agents. The coffee drinker feels that the drink is thicker than just plain water, and that there is a sense of viscosity about the way the coffee feels on the tongue and in the mouth.
Strong describes the efficiency of the coffee extraction and balance of the brewing ratio. Extraction of coffee is how we measure the amount of solubles that, during brewing, are removed from the coffee grounds and enter the water. The higher the ratio of coffee grounds to water, the greater the flavor strength of the finished cup.
DARK COFFEE – YOU GOT WHAT YOU ASKED FOR!
The coffee roasting process is what determines the final roast color of the coffee bean. When someone purchases a bag a coffee, the roast level of that coffee is usually indicated somewhere on the bag so that the drinker knows what level of roast to expect from their cup after brewing. So, if you buy a bag of a light roasted coffee, the finished color will be exactly that: light.
If it is dark coffee that you want, you need to make sure that the bag of coffee you purchase indicates it.
HOW DOES EXTRACTION AFFECT THE COFFEE'S STRENGTH AND RICHNESS?
As the coffee grounds are exposed to the water, the length of time as well as the water to coffee grounds ratio has a direct impact on the finished strength and body profile of the cup of coffee.
The Specialty Coffee Association states that the best extraction ratio lies somewhere between 18% and 22%. (Of course, some people prefer their coffee stronger, or weaker – there is no one absolute correct ratio, just what the coffee drinker likes.)
During brewing, the earliest notes to be extracted are the acidic and fruity flavors, meaning that an under-extracted coffee could taste sour. When the extraction time is longer, more bitterness is produces but with a thicker, creamier body.
CONTROLLING EXTRACTION TO GET YOUR DESIRED RESULTS
Extraction is determined by coffee grind size, water temperature, and contact time.
The main concept to keep in mind when determining grind size is the surface area of the coffee grounds coming into contact with brewing water.
The coarser the grind, the quicker water will flow through the coffee and a lesser amount of water comes into contact with the coffee grounds. As such, less extraction will take place. Conversely, the smaller the grind size, the less gaps for water to flow through as well as a greater amount of surface area contact.
For this reason, grind consistency is a crucial factor in controlling extraction. If your grinds are different sizes, some of them will be extracted more than others, leading to an unpredictable finished cup of coffee.
There are three main factors that water and water temperature play in controlling coffee extraction. The quality of water being used to brew, the amount of turbulence with which coffee and water interact, and the ratio of coffee to water.
The water quality can make a difference in the overall finished taste of the coffee; however, most available water sources are perfectly acceptable. Tap water, filtered water, and commercially bottled water will all provide the coffee drinker with quality water to brew coffee with.
Turbulence is how much the coffee/water moves and interacts with coffee grounds while immersed. For some brewing methods, such as French Press, coffee drinkers prefer to agitate the coffee grounds inside the French Press in order to create more contact with the water.
A universal starting point and recommendation for coffee to water ratio is 1:16, meaning 1 gram of coffee to 16 grams of water. Some grinders come with a built-in scale, but if your grinder does not have this feature, an electrical kitchen scale will work just fine. To increase the strength of the coffee, you would decrease the ratio from 1:16 to 1:14. However, as with all things too much of a good thing isn’t always best: there will come a point in the ratio where the strength of the coffee is unpleasant. Coffee enthusiasts will need to experiment with the ratio to find what works best for their palate.
Lastly, water temperature plays a role in the extraction efficiency process. 195°F to 205°F is the ideal range of water temperatures for coffee brewing. Using water that is below 195°F would cause under-extraction whereas brewing above 205°F could over-extract the coffee making it taste more bitter.
There is a multitude of resources that offer guidance on extraction times for each and every brewing method. However, remember that all other factors being equal, the shorter the extraction time, the fruitier and more acidic the coffee becomes. Too short, and it will turn sour. Conversely, the longer the extraction time, the more body the coffee develops. Too long and it becomes bitter.