Extraction Basics – Page 1
This brief Coffee Brewing Guide will have you enjoying your Flower Power Coffee in your own home in no time! In this guide, we'll start with the coffee extraction process, the equipment you'll need for brewing, and the methods to consistently brew a delicious cup!
Coffee Extraction is the removal of the fats, lipids, volatile oils, and organic acids from the coffee bean and into the water that you will drink. In very simple terms, it is whatever the water takes from the bean so that you can enjoy an optimum cup of coffee beverage.
Roasted coffee beans are approximately 28% water-soluble. This means that you can extract just under a third of the bean's mass in water with the rest being thrown out afterwards. It is an art and a science to ensure that the ideal amount of usable bean content is extracted as too much or too little will greatly impact the taste. There is no harm in over/under extracting, but it will be the difference between a mediocre cup of coffee and a great cup of coffee!
The goal of extraction is consistency. The main factors influencing the overall extraction uniformity are the bed distribution, agitation, water distribution and the particle distribution. The key is to ensure the water covers the maximum surface area of the coffee. For pour-overs, keep the water moving across the bed and stir the bed once during the initial part of the saturation.
Time – Page 2
There are 3 main variables (a.k.a. "The 3 T's") which affect the quality of extraction: Time, Turbulence and Temperature.
Time refers to the brewing time, or the time that the water is in contact with the coffee grounds. Extractions occurs rapidly and slows down over time as the coffee mass and oils are removed from the grounds. Again, too little water contact with the beans will result in a diluted/weak coffee. Too much water contact will result in a burnt/bitter tasting coffee.
The time that the water should be in contact with the beans depends on brewing method. Pour-over and plunge presses should be around around 4 minutes while drippers should drip for between 2-3 minutes.
Another factor to consider is the time between brewing and consumption. Coffee is only fresh for about 10 - 15 minutes after brewing - there's just no substitute for a fresh cup of coffee! Try to brew just enough coffee that will be consumed right away. Aficionados would never reheat a cup of coffee but of course, there is no harm in doing so and it is certainly preferable to wasting it.
For manual brewing methods, you will need to experiment with the time the water is in contact with the beans and adjust your times accordingly. In general, it is recommended to keep the water in contact with the beans for between 3 and 4 minutes for pour-over / pressing methods. Pour the water slowly in concentric circles allowing the water to raise the slurry about halfway up the cone. Stir the slurry gently once (and only once) to ensure full saturation. Continue to pour the water and allow the bed to bubble and expand to maximum size. As it begins to subside about halfway down, add more water. The duration between expansions should be approximately 30-45 seconds. This technique is called "blooming the coffee" and will dramatically improve the extraction quality and overall "robustness" of the coffee.
Turbulence – Page 3
Turbulence is created as water passes through, over, and around the coffee grinds. Turbulence allows the particle clumps to separate to allow for maximum surface area of the coffee to come into contact with the coffee. For drip brewing, the turbulence is created by the release of the water. For pour overs, the turbulence is created by keeping the coffee-pot spout in continuous motion. If the dripping/pouring is too slow, there will be inconsistency. The grounds in the middle of the coffee bed will be wet and over-saturated and the coffee on the outside will be dry and under-extracted.
For pour-overs, keep the coffee-pot spout moving in slow concentric circles to ensure consistent wetting of the coffee bed. The goal is to have as much of the coffee come into contact with the water as possible. When the hot water is first introduced to the coffee, some grinds will float to the top due to the gasses being released. For this reason, it is important to stir the coffee bed gently (just once is sufficient) to submerge the crust. At the end of the coffee extraction, the coffee beverage will remain in the vessel. Since the extraction quality will vary between the first minute and the last, simply stir the coffee in the vessel before serving.
For the French Press, place the grounds in the device and add twice as much water as coffee. Allow the coffee to steep for 30 seconds with the cap and plunger in place to keep the coffee hot. After 30 seconds, add the remaining water, stir gently for a few seconds and press the plunger gently so that any floating coffee is submerged. After waiting for another 3 and a half minutes, depress the plunger to the bottom and immediately serve from the French Press with the plunger all the way down. The device will filter out the grinds however there will be some liquid remaining in the press - do not pour all of the liquid into your cup since you will get sediment which will alter the taste. Do not let the coffee sit in the press as this will cause it to continue brewing and over-extract.
Temperature – Page 4
Hot water effectively removes the coffee-flavoring solubles. Brewing water at cooler temperatures for the same amount of time will result in a lighter extraction and will result in a flat taste. Alternatively, brewing at a temperature range that is too hot will result in bitter coffee.
For manual brewing methods, it is recommended to use an average temperature between 195-205 degrees Fahrenheit (91-94 Celsius). Although the temperature can be approximated by pouring a couple minutes after it reaches a rolling boil (212 degrees Fahrenheit - 100 degrees Celsius), using a thermometer will remove all guess work. Also note that boiled water removed from heat will lose approximately 1 degree Fahrenheit every 15 seconds. For this reason, you'll want to start on the upper range of temperatures which then factors in the cooling during the pouring process. Do not put boiling water onto coffee as this will actually burn the grounds. Another tip is to use hot water to warm up the brewing vessel, cup, and other equipment to help slow down the cooling process during preparation.
For pour-overs, the water level of the coffee bed greatly impacts the temperature during the extraction process. Keep the level low will help slow down the flow rate and will help maintain a more consistent temperature as the water passes over the coffee. A high level will drain too fast and dissipate the heat too quickly - this is not desirable.
Always remember, coffee is only as good as its weakest link. Compared to the other variables, temperature can be more difficult to control. Do not stress if the temperature is not exact to the degree but do ensure that it falls within the range given above.
Equipment (cont’d) – Page 6
Filters are necessary to remove the fine particles which can negatively impact the flavor and make the appearance cloudy. White, oxidized filters work the best as they do not impact the flavor like natural (e.g. hemp, bamboo) filters can. An important tip is to always wet the filters prior to adding the coffee as this helps ensure the proper flow.
Since coffee can have different density, measuring by volume is not as accurate as measuring by weight. Aficionados will even measure the water by weight rather than by volume since it will give the most precise measurement.
Thermometer / Timer:
Since temperature and time are important factors of extraction, it makes sense to be as precise as possible for these measurements.