This set focuses on milk alternatives, advanced brewing dynamics, and the specific impact of the “Double Washed” process that makes Kenyan coffee world-famous.
Article 171: The “Kenyan Process”: Double Washing
(Category: Coffee Education | Word Count: ~320)
While many countries use a “washed” process, Kenya is famous for its Double Washed (or 72-hour) method. This is the gold standard for clarity and acidity.
- Pulping & First Fermentation: The skin is removed, and the beans ferment in a dry tank for 24 hours to break down the mucilage.
- The First Wash: The beans are washed with fresh water.
- Second Fermentation: The beans are placed back into a tank with water for another 12 to 24 hours. This “soaking” phase allows for further chemical changes that increase the complexity of the organic acids.
- Final Grading: The beans are washed through long channels where the “floaters” are removed, and the dense, high-quality beans are sent to the drying beds.
This process uses a lot of water and labor, but it is the reason why Kenyan coffee tastes so “clean” compared to coffees from other regions.
Article 172: Oat Milk vs. Dairy: The Steaming Difference
(Category: Barista Skills | Word Count: ~280)
As dietary preferences change, baristas must master plant-based milks. Oat milk has become the favorite of specialty baristas because its flavor profile complements coffee without overpowering it.
The Steaming Technique: - Aeration: Oat milk requires less air than dairy. If you stretch it too much, it becomes “bubbly” and stiff rather than silky.
- Temperature: Oat milk is more sensitive to heat. While dairy shines at 65^\circ\text{C}, oat milk can start to taste “grainy” or “burnt” if it goes above 60^\circ\text{C}.
- Wait Time: Plant milks separate faster than dairy. You must pour your latte art immediately after steaming, or the foam will “set,” making it impossible to create fine details.
Mastering the “texture” of oat milk is essential for any modern barista looking to provide an inclusive menu.
Article 173: What is “Channeling” and How to Fix It?
(Category: Barista Skills | Word Count: ~240)
Channeling occurs when water finds a “weak spot” in the coffee puck and rushes through it at high pressure, rather than moving evenly through all the grounds.
How to spot it:
If you use a bottomless portafilter, you will see “spurts” of coffee spraying out. If you use a spouted one, you’ll notice the shot suddenly “blonds” very early and tastes watery and bitter at the same time.
The Fixes: - Distribution: Ensure the coffee is level in the basket before you tamp.
- Tamping: Make sure your tamp is perfectly horizontal.
- Basket Size: Don’t under-dose your basket. If there is too much space between the shower screen and the coffee, the force of the water will “crack” the puck.
Article 174: The “Turbulence” Factor in Brewing
(Category: Brewing Methods | Word Count: ~210)
Turbulence is the mixing or “swirling” of coffee grounds caused by the force of the water being poured. In manual brewing (like a V60), turbulence is a double-edged sword.
The Good:
Controlled turbulence (achieved by a steady circular pour) ensures that no grounds are left “dry” and that the water is constantly finding new surfaces to extract flavor from.
The Bad:
Too much turbulence (pouring too fast or from too high) can “clog” the paper filter by forcing tiny particles (fines) into the pores of the paper. This slows down the draw-down time and leads to over-extraction and bitterness. The goal is a “gentle” turbulence that keeps the bed flat and active.
Article 175: The Chemistry of the “Crema”
(Category: Coffee Science | Word Count: ~230)
Crema is the tan-colored foam on top of an espresso. It is an emulsion of air, CO_2 gas, and coffee oils.
Why it exists:
When hot water hits the coffee at 9\text{ bars} of pressure, it dissolves the CO_2 gas that was trapped inside the bean during roasting. When the liquid leaves the portafilter and returns to normal atmospheric pressure, the gas “bubbles out” of the liquid, much like opening a soda.
The Flavor Myth:
Many people think crema is the best part of the shot, but on its own, crema is actually quite bitter and ashy. Its real value is in the aroma it traps and the creamy mouthfeel it provides when stirred into the rest of the shot.
Article 176: Understanding “Organic” Certification
(Category: Coffee Business | Word Count: ~290)
For a coffee to be labeled “Organic,” it must be grown without the use of synthetic fertilizers, pesticides, or herbicides for at least three years.
The Challenge in Kenya:
Many smallholder farmers in Kenya are “organic by default”—they cannot afford expensive chemicals. However, getting the actual Certification is very expensive for a small cooperative. It requires strict paperwork, separate processing lines at the factory, and annual audits.
The Benefit:
Certified organic coffee often fetches a higher price in Europe and North America. For the consumer, it ensures a product free of chemical residues. For the farmer, it encourages “Agroforestry” (planting trees that fix nitrogen into the soil naturally), which can lead to better long-term soil health.
Article 177: Why We “Season” New Burrs
(Category: Barista Skills | Word Count: ~190)
If you buy a brand-new professional coffee grinder, you might notice the first few kilograms of coffee taste slightly “off” or inconsistent. This is because the steel burrs are “too sharp.”
New burrs have microscopic “burrs” (rough edges) from the manufacturing process. These edges cause the coffee to shatter irregularly, creating too many fines.
The Seasoning Process:
Most cafes will run 5\text{ to }10\text{ kg} of “old” or cheap coffee through a new grinder before using it for customers. This “polishes” the metal edges, leading to a much more consistent grind size and better-tasting shots from day one of service.
Article 178: The “V60” 4:6 Method
(Category: Brewing Methods | Word Count: ~310)
Developed by World Brewers Cup Champion Tetsu Kasuya, the 4:6 Method is a specialized way to use the Hario V60.
The Theory:
Kasuya divides the total water into two parts: 40\% and 60\%. - The first 40%: Adjusts the balance between Acidity and Sweetness.
- If the first pour is larger, the coffee is more acidic.
- If the second pour is larger, the coffee is sweeter.
- The remaining 60%: Adjusts the Strength (concentration).
- This is divided into 3 equal pours.
The Grind:
This method requires a very coarse grind (like Kosher salt). Because you are pouring in distinct pulses, the water drains through quickly, preventing the bitterness often found in finer-grind pour-overs. This is a favorite technique for showcasing the “wine-like” acidity of Kenyan SL28 beans.
Article 179: The Role of “Silver Skin” (Chaff)
(Category: Roasting Knowledge | Word Count: ~220)
As coffee roasts, the thin, papery layer called the “silver skin” expands and peels off. In the roasting world, this is called Chaff.
In the Roaster:
Chaff is highly flammable. Roasters have “chaff collectors” (cyclones) that suck this material away from the heat. If it isn’t removed, it can catch fire or impart a “papery” or “burnt” taste to the beans.
In the Cup:
Some chaff remains trapped in the “center cut” of the bean. This is harmless and actually contains high concentrations of antioxidants. If you see white flakes in your ground coffee, don’t worry—it’s just a sign of a well-developed light or medium roast.
Article 180: The “Salami Shot” Exercise
(Category: Sensory Skills | Word Count: ~240)
The “Salami Shot” is a classic training exercise to understand how extraction changes over time.
The Exercise:
Start an espresso shot and switch the cup every 5 or 10 seconds until the shot ends. You will end up with 4 or 5 different cups. - Cup 1 (0-10s): Extremely salty, sour, and thick. (Under-extracted)
- Cup 2 (10-20s): Sweet, syrupy, and acidic. (The “Sweet Spot”)
- Cup 3 (20-30s): Watery and starting to become bitter.
- Cup 4 (30s+): Ashy, bitter, and dry. (Over-extracted)
By tasting these “slices” individually, a student learns exactly why we stop a shot when we do. It illustrates that “more coffee” (longer yield) isn’t always better!