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The Barista’s Path: From Bean to Cup — Chapter 7. Coffee Extraction

Steaming roasted dark coffee beans from a cup

Mastering Coffee Extraction: The Science Behind a Perfect Brew

Brewing an exceptional cup of coffee at home is more than just a morning ritual; it’s a fascinating blend of art and science. At Café Nairobi, your trusted source for premium specialty Kenyan coffee, we believe that understanding the science of coffee extraction is the key to unlocking the full, vibrant potential of every bean.

From our roasting home in St. Augustine, Florida, we are dedicated to helping coffee lovers transform their daily brew from average to extraordinary. By diving deeper into how water interacts with coffee grounds, you’ll learn how to reveal the incredible flavors, aromas, and balance that Kenyan coffees are celebrated for worldwide.

What is Coffee Extraction?

At its core, extraction is the process by which hot water dissolves soluble compounds from your ground coffee. Think of it as drawing out all the essential elements—flavors, aromas, and oils—that make coffee so enjoyable.

This critical process influences:

  • Which flavors appear: From bright, fruity citrus to deep, chocolatey undertones.

  • Balance in your cup: How acidity, sweetness, and bitterness coexist.

  • Body and aftertaste: The texture, mouthfeel, and lingering finish.

By controlling variables such as grind size, brew time, water temperature, and coffee-to-water ratio, you gain the power to intentionally shape your coffee experience. This is especially important with single-origin Kenyan coffee beans, which are known for their complexity and range of tasting notes.

Coffee extraction using a coffee maker

The Stages of Coffee Extraction: A Flavor Journey

Extraction doesn’t happen instantly; it unfolds in stages, each with its own impact on flavor:

  1. First Stage (Under-extraction)
    The initial compounds to dissolve are often bright acids and delicate, fruit-like flavors. Stop here, and your coffee may taste grassy, sour, or weak.

  2. Middle Stage (Balanced Extraction)
    As brewing continues, sweetness and complexity develop. This is the “sweet spot” where the coffee shines—capturing the hallmark balance of Kenyan coffee, with its mix of fruity brightness and honeyed sweetness.

  3. Final Stage (Over-extraction)
    If the brew drags on too long, bitter and astringent compounds dominate. The result is a harsh, unpleasant cup that masks the coffee’s natural beauty.

The goal is to extract enough to highlight sweetness and complexity while avoiding excessive bitterness.

Key Factors Affecting Your Coffee Extraction

Mastering these variables will empower you to consistently brew café-quality coffee at home.

1. Grind Size

This is arguably the most influential factor.


  • Finer Grind: Increases surface area, accelerating extraction but slowing water flow. Best for espresso or Turkish coffee.

  • Coarser Grind: Slows extraction, with faster water flow. Ideal for French press or cold brew.

  • Pour-over Coffee: Start with medium to medium-fine grind.


💡 Pro Tip: Invest in a burr grinder. Unlike blade grinders, which chop unevenly, a burr grinder crushes beans uniformly, producing consistent particle size. This ensures even extraction and avoids “bitter-sour” imbalance.

2. Brew Time

The contact time between water and grounds directly affects flavor.

  • Longer Brew Time = More extraction.

  • Too Long = Over-extracted, bitter taste.

  • Too Short = Under-extracted, sour taste.

For pour-over, aim for 2:45–3:30 minutes from the first pour to the last drip.

3. Water Temperature

Water is the unsung hero of extraction—it makes up 98% of your brew.

  • Ideal Range: 195–205°F (90–96°C).

  • Higher Temps: Extract faster, yielding more body but risk bitterness.

  • Lower Temps: Highlight acidity but risk under-extraction.

For light roasts (like many Kenyan coffees), use slightly hotter water, around 205–210°F (96–99°C), to unlock vibrant fruit and floral notes.

4. Coffee-to-Water Ratio

This sets the strength of your brew.

  • General Ratio: 1:17 (1g coffee to 17g water).

  • Pour-over: 1:15–1:17.

  • French Press: 1:15.

  • Espresso: Around 1:2 (18g coffee → 36g espresso).

Measuring is key—use a digital scale for consistency.

How to Measure Extraction: Your Taste Buds are Key

Professional baristas use refractometers to measure Total Dissolved Solids (TDS) and extraction yield (ideally 18–22%). But at home, your best tool is your palate.

  • Sour, Thin, Grassy? → Under-extracted. Try finer grind, longer time, or slightly hotter water.

  • Bitter, Dry, Harsh? → Over-extracted. Try coarser grind, shorter time, or cooler water.

  • Sweet, Complex, Balanced? → You’ve nailed it.

The Practical “Dialing-In” Method

When you open a fresh bag of Café Nairobi premium Kenyan coffee, think of brewing as a process of discovery.

  1. Start with a Recipe: Example: 20g coffee, 320g water, 205°F.

  2. Brew and Taste: Evaluate acidity, sweetness, and bitterness.

  3. Adjust One Variable at a Time: Finer grind for sour coffee, coarser for bitter.

  4. Repeat Until Balanced: Find the “sweet spot” that brings out the bright acidity and berry notes Kenyan beans are famous for.

This method works across all brewing methods—pour-over, French press, espresso, or cold brew.

Using Cupping to Understand Extraction

Cupping, the professional practice of evaluating coffee, is an excellent way to sharpen your palate. By tasting coffees side by side, you’ll detect under- or over-extraction more clearly and learn to appreciate subtle differences in roast level and origin.

Home cupping kits are widely available, and with Café Nairobi beans, you can experience the full spectrum of Kenyan coffee flavor profiles—from floral and tea-like to bold and chocolatey.

Brewing Methods and Extraction Tips


  • Pour-Over Coffee Beans: Highlight clarity and acidity. Use medium-fine grind, steady pour.

  • French Press Coffee: Accentuates body. Use coarse grind, 4-minute brew.

  • Espresso: Rich, concentrated. Use fine grind, high pressure, 25–30 sec extraction.

  • Cold Brew Coffee Beans: Smooth, low-acid. Use extra-coarse grind, steep 14–18 hrs.


Your Action Steps This Week: Unlock Kenyan Flavors!

Ready to practice?

  1. Pick a brewing method—drip, pour-over, French press, espresso.

  2. Use freshly roasted Café Nairobi beans: Our premium Kenyan coffee is roasted in small batches to bring out unique characteristics.

  3. Brew, taste, and record your impressions.

  4. Adjust variables step by step until you find the balance.

  5. Share your journey—tag us on Instagram @CafeNairobi and inspire other home brewers.

Conclusion: Science Meets Heritage

Mastering extraction is more than a brewing skill—it’s a way of honoring the heritage of every farmer who nurtures Kenya’s coffee trees and every roaster who brings out their best. With the right knowledge, tools, and freshly roasted beans, your home brew can rival any café.

👉 Ready to experience the full potential of Kenyan coffee? Shop our collection of single-origin, freshly roasted Café Nairobi beans at CafeNairobi.com—and taste the difference science and tradition make in every cup.

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