Brewing Fundamentals.
VOCABULARY (in mostly our own words)
Here is a short list of frequently used terms for coffee brewing. Of course there are plenty of others, but we consider these to be the most discussed.
Variables
The different components that work in tandem with one another to produce a cup of coffee.
Extraction
The percentage of good and bad flavor that was a result of how the coffee was brewed. When calculated fully, it is considered extraction yield.
TDS
Total Dissolved Solids. How much coffee was truly brought out during brewing? Beneficial to number-geeks.
Over extracted
Disproportionate flavor due to too much coffee solids being dissolved. Usually characterized by tasting astringent, bitter, and/or chalky.
Ratios
The amount of coffee used, multiplied by a set number. Usually in the format of coffee:water or water:coffee.
Under extracted
Disproportionate flavor due to too little coffee solids being dissolved. Usually characterized by tasting dull, sour, or watery.
Dosages
The amount of coffee used prior to grinding. Usually expressed in grams in most recipes.
Blooming:
The first stage in coffee prepared in manual brewing. It is the initial release of CO2 that was trapped in the coffee during roasting. Executed by pouring a small amount of water over the grounds. Also serves as a passageway for the remaining water to be poured.
Honorable Mentions:
Brew Bed: The ground coffee that is resting in the filter, inside the dripper.
Agitation: Used to describe anything that causes the coffee in the brew bed to be moved around. Can be done by direct stirring, swirling, or simply by the speed in which water is being introduced.
Yields: The amount of liquid that was actually drawn out of the coffee, expressed in grams.
We find notetaking to be one of the most effective ways to grow manual-brewing skills.
Starting somewhere // Fundamental variables
No matter where you are in your coffee journey, everyone has a starting point.
You will find that understanding the basic variables in coffee brewing is key to having a balanced perspective of brewing.
Grind size.
In order to maintain consistent results, using a grind that is even in size makes a substantial difference when brewing. It is usually best to grind on machines that have some sort of burr blade, since they are the most refined and can be controlled down to a decimal number on some machines.
Water temperature.
A fast way to understand water temperature is a quick departure from talking about coffee at all, but instead talking about cooking.
When you place meat on a hot pan, it begins to cook immediately. The higher the heat, the faster (albeit uneven) the meat will cook. Whereas using a slightly lower heat and amount of time, the meat will cook more thoroughly. This results in the flavor, mouthfeel, texture, and aftertaste to become much more balanced than if you had only cooked on high heat. There are plenty of exceptions to this rule, but the basic idea remains.
There is much discussion as to what is considered to be the perfect temperature for brewing coffee. For the sake of having a starting point we will state the range to be between 198 - 205 Fahrenheit.
Our favorite rule to keep in mind to determine what temperature to start with is this:
Higher altitude coffees are higher in density. In turn, they require a higher temperature to dissolve. The same is said for lower altitude coffees. Lower temp dissolves solids slower, higher dissolves faster.
Kettle.
This is an aspect that can easily be overlooked when discussing variables. The rate that water reaches the brew bed has a substantial impact on how the grounds interact with the dripper that they are in. Apart from the actual weight of the kettle and water capacity, there are other embedded details here, such as: flow restriction inside the neck, length of neck, height of neck, and heat retentive capabilities.
These things are important because they are responsible for stirring up the brew bed, which is a form of agitation.
Weight.
The topic of weight can be broken into three related parts -
Ratios (coffee:water)
Dosages (how much coffee to start with)
Yields (how much liquid actually ended up in the cup)
The part to take away here is ratios. Much like water temperature, there is much debate as to what the perfect ratio is. For most of the specialty coffee industry and filter-brewed coffee, 1:15 - 1:17 is used, including the decimals in between.
We will start at 1:16. The way one deciphers those numbers is by simply deciding the amount of coffee desired. A fair average amount of coffee would be 20g.
Then it is simply a matter of multiplication
1:16 (coffee:water)
20 x 16 = 320
20g:320
Yields are important to measure when getting into reading TDS. Remeasuring the liquid after brewing will help solidify just how much water the ground coffee retains.
Time.
A variable that is translated across nearly every coffee extracting method is time. Without measuring time, it is difficult to reevaluate when an issue arises, and is especially important in cafes.
Here is an example:
John arrives on shift and sees there is a new batch of coffee from the roaster, he decides to dial it in on v60 in order to make it a coffee he is confident in serving. He writes down his numbers and finally lands on what he is wanting to draw out of it. A few days later Susan clocks in to her morning shift. One of her first customers orders the coffee John has set a recipe for. Susan follows his recipe, but fails to pay attention to her bloom time and final goal time. After some time, the grounds are dry and she pours the coffee for the eager customer. A few minutes later, the customer returns and says they are dissatisfied. Susan is apologetic and makes the customer a latte instead, to satisfy them. The same situation happens with several other customers throughout the day. Susan is frustrated and does not know what to do. She texts John and asks him what to do. He questions her as to what time the drink had been finishing, and she told him she had not been paying attention. After a few more texts, John has her prepare the drink again, this time paying close attention to the time. Susan reports back to him saying that it finished in 5 minutes and 34 seconds. John’s recipe was set to finish in 3 minutes.
The purpose of this long example is to clarify that as coffee ages and the surrounding environment (room temperature, humidity, etc) changes, recipes often need to be tweaked. Time happens to be one of the largest revealing factors of whether a recipe needs to be readjusted or not.
