We are moving into the final stages of the curriculum, focusing on “Third Wave” philosophy, water chemistry impact, and advanced milk chemistry.
Article 201: The “Third Wave” Coffee Movement
(Category: Coffee Education | Word Count: ~330)
To understand modern barista work, you must understand the “Waves” of coffee history.
- First Wave (1800s – 1960s): Coffee becomes a mass-market commodity (folders, instant coffee). The goal was convenience and caffeine.
- Second Wave (1970s – 1990s): The rise of “Espresso culture” and chains like Starbucks. Coffee becomes an “experience” with flavored lattes and darker roasts.
- Third Wave (2000s – Present): Coffee is treated like fine wine or craft beer. The focus shifts to origin, variety, and processing.
The Third Wave Philosophy:
In the Third Wave, we celebrate the farmer. We want to taste the difference between a coffee grown in Nyeri and one grown in Ethiopia. We use lighter roasts to preserve the natural acids and sugars of the bean. As a student at Kenya Coffee School, you are being trained as a “Third Wave” professional—someone who views coffee as a craft, not just a commodity.
Article 202: What is “Alkalinity” in Water?
(Category: Coffee Science | Word Count: ~280)
In previous articles, we discussed minerals like Magnesium. Now, we must look at Alkalinity (specifically Bicarbonate).
The Buffer Effect:
Alkalinity acts as a “buffer” for acid. If your water has high alkalinity, it will physically neutralize the organic acids in your coffee. - The Result: Your Kenyan coffee, which should be bright and “sparkling,” will taste flat, chalky, and dull. It may even taste slightly “soapy.”
The Low End:
If your alkalinity is too low, the acids in the coffee have nothing to balance them out. - The Result: The coffee tastes sharp, vinegary, and unpleasantly “aggressive.”
For Kenyan beans, which are naturally very high in acid, we look for a “moderate” alkalinity (around 40 – 70\text{ ppm}) to make the acidity taste sweet and vibrant rather than sour.
Article 203: The “Swan” Latte Art Pattern
(Category: Barista Skills | Word Count: ~260)
The Swan is considered an advanced latte art pattern because it combines three different techniques: the Rosetta, the Heart, and a steady “drag.”
How to Pour it: - The Wing: Start like you are pouring a Rosetta, but instead of finishing it, you tilt it to one side of the cup. This creates the “body” or “wing.”
- The Neck: As you reach the top of the Rosetta, lift the pitcher slightly and draw a steady, thin line of milk back toward the empty space in the cup. This is the neck.
- The Head: At the end of the neck, drop the pitcher close to the surface to create a small “Heart.”
- The Beak: Drag the pitcher through the heart to finish the head.
Mastering the Swan proves that a barista has complete control over their flow rate and hand movement.
Article 204: Denaturation of Milk Proteins
(Category: Barista Skills | Word Count: ~240)
When we steam milk, we are essentially cooking it. The most important change happens to the Whey Proteins.
As the temperature rises, these proteins “unfold” or denature. This is what allows them to coat air bubbles and create stable foam. However, there is a limit. - At 60^\circ\text{C} (140^\circ\text{F}): The proteins are perfectly denatured to provide sweetness and structure.
- Above 70^\circ\text{C} (158^\circ\text{F}): The proteins begin to break down completely and release sulfur. This is why “extra hot” milk smells like boiled eggs and loses its creamy texture.
Always aim for that 60^\circ\text{C} – 65^\circ\text{C} window to ensure the proteins work for you, not against you.
Article 205: Why the “Basket Shape” Matters
(Category: Barista Skills | Word Count: ~220)
If you look at espresso filter baskets, some are conical (tapered at the bottom) and some are flat-bottomed. - Conical Baskets: Found in many older or home machines. They are easier to “seal” with a tamp, but they tend to over-extract the center of the puck and under-extract the edges.
- Flat-Bottomed (Precision) Baskets: Used in specialty cafes (like VST or Pullman baskets). These have holes that go all the way to the edge.
The Benefit:
Precision baskets allow for a much more even extraction. Because the holes are uniform and reach the edges, water moves straight down through the whole puck. This allows baristas to grind finer and get more sweetness out of their Kenyan coffee without the bitterness caused by uneven flow.
Article 206: Understanding “Volatiles”
(Category: Coffee Science | Word Count: ~210)
The “smell” of coffee is made up of Volatile Organic Compounds (VOCs). They are called “volatile” because they turn into gas at room temperature.
The moment you grind coffee, you increase the surface area by thousands of times. This allows these gases to escape into the air. Within 15 minutes of grinding, nearly 60\% of the most delicate “floral” and “fruity” aromas are gone. This is why a professional barista never grinds coffee in advance. We grind “on demand” for every single cup to ensure the customer gets all those beautiful volatiles in their cup, not in the air.
Article 207: The “Moka Pot” Technique
(Category: Brewing Methods | Word Count: ~290)
The Moka Pot (Stovetop Espresso) is an iconic Italian brewer. While it doesn’t produce “true” espresso (it only reaches about 1.5\text{ bars} of pressure), it produces a very strong, rich cup.
The Specialty Tip:
The biggest complaint about Moka Pots is that the coffee tastes “burnt.” This happens because the dry coffee grounds sit in the metal brewer while the water heats up, essentially “toasting” them before they brew.
The Fix: - Use Boiling Water: Fill the bottom chamber with already-boiling water. This drastically reduces the amount of time the brewer sits on the stove.
- Use a Towel: Be careful—the base will be hot!
- Cool it Down: As soon as the coffee starts to “hiss” and turn pale, run the base of the Moka Pot under cold tap water. This stops the extraction instantly and prevents the “bitter” end-of-brew flavors from entering your cup.
Article 208: Why Some Coffee is “Shiny”
(Category: Roasting Knowledge | Word Count: ~190)
If you see coffee beans that look “oily” or “shiny,” it tells you a lot about the roast level and age.
During roasting, the internal structure of the bean becomes porous. If the roast is very dark, the heat forces the natural lipids (oils) from the center of the bean to the surface. - Fresh Dark Roast: Will be very shiny.
- Old Light Roast: May eventually become shiny as the oils slowly migrate out over several weeks.
In specialty coffee, we usually prefer “matte” (non-shiny) beans. This indicates a lighter roast that has preserved the delicate acids and hasn’t yet started to oxidize or turn rancid.
Article 209: The “Two-Step” Pour for V60
(Category: Brewing Methods | Word Count: ~230)
While there are many complex recipes, the “Two-Step” pour is the foundation of consistency. - The Bloom: Pour double the weight of the coffee (e.g., 30\text{g} water for 15\text{g} coffee). Stir gently and wait 30–45 seconds.
- The Main Pour: Pour the remaining water in one steady, slow, spiral motion.
The Advantage:
By pouring the rest of the water in one go (rather than multiple small pulses), you maintain a high thermal mass. The water stays hotter for longer, which helps extract those difficult-to-reach sugars in high-density Kenyan beans. It also creates less “turbulence” at the end, leading to a cleaner, clearer finish.
Article 210: What is a “Single Origin” Blend?
(Category: Coffee Education | Word Count: ~310)
This sounds like a contradiction, but it is common in Kenya. A “Single Origin” means the coffee comes from one country and usually one region (like Nyeri).
The Blend Part:
Most Kenyan “lots” from a factory are actually a blend of: - Different Farmers: 500 smallholders might deliver to the same factory.
- Different Varieties: A single bag might contain SL28, SL34, and a little Ruiru 11.
- Different Days: The “Lot Number” might represent three different days of picking.
This “natural blend” is actually a good thing! It creates a complex profile that a single tree could never produce. When we talk about “Single Origin,” we are celebrating the terroir (the soil and climate) of a specific place, even if many different hands helped produce the final bag.