Why is Coffee Bitter? & How to Balance It ☕

Bitterness in coffee comes from a combination of natural compounds, roasting techniques, and brewing methods. Understanding these elements helps create a smoother, more enjoyable cup.

1️⃣ Natural Compounds in Coffee

Coffee beans contain several compounds that naturally contribute to bitterness.

🔬 Chlorogenic Acids

  • These are antioxidant compounds found in raw coffee beans.
  • When coffee is roasted, chlorogenic acids break down into chlorogenic acid lactones (mild bitterness) and phenylindanes (strong bitterness).
  • The longer the roasting, the more chlorogenic acids break down, increasing the coffee’s bitterness.

⚡ Caffeine

  • Caffeine is naturally bitter, but it’s not the main reason coffee tastes bitter.
  • Arabica beans contain less caffeine than Robusta beans, which is why Robusta coffee tends to be more bitter.
  • Caffeine’s bitterness is more noticeable in espresso, where the extraction is concentrated.

🧬 Proteins & Lipids

  • While proteins and lipids (fats) are not bitter themselves, they impact how we perceive bitterness.
  • Lipids create a smoother texture, which can help soften harsh bitter notes.
  • The presence of proteins can influence how coffee interacts with water during brewing, affecting the extraction of bitter compounds.

 

2️⃣ Roasting & Bitterness

The roasting process plays a major role in determining how bitter a coffee will be.

☀️ Light Roast

  • Retains more of the original bean’s acidity and floral flavors.
  • Contains fewer bitter compounds because the chlorogenic acids haven’t broken down as much.
  • Can taste bright, tangy, or slightly sour instead of bitter.

☕ Medium Roast

  • Offers a balance of acidity, sweetness, and bitterness.
  • Caramelization of sugars occurs, creating notes of chocolate and caramel.
  • Lactones (mildly bitter) develop at this stage, but phenylindanes (strong bitterness) are not yet dominant.

🔥 Dark Roast

  • More chlorogenic acids have broken down into phenylindanes, which have a strong, lingering bitterness.
  • The flavors shift towards smoky, burnt, and earthy tones.
  • Over-roasting can create an unpleasant, ashy bitterness.

The key takeaway: the darker the roast, the more bitter the coffee will be.

3️⃣ Brewing Mistakes That Increase Bitterness

Even high-quality coffee can become too bitter if it’s brewed incorrectly.

🚨 Over-Extraction

  • If coffee is ground too fine or brewed too long, too many bitter compounds are extracted.
  • This can happen in espresso machines, French presses, or when steeping coffee for too long.
  • A coarser grind and controlled brewing time prevent excessive bitterness.

🔥 Water Temperature

  • The ideal brewing temperature is 90–96°C (195–205°F).
  • If water is too hot, it extracts harsher bitter compounds too quickly.
  • Let boiling water cool for 30–60 seconds before pouring to avoid burning the coffee.

📏 Wrong Coffee-to-Water Ratio

  • Using too much coffee with too little water leads to over-extraction, making the coffee bitter.
  • A good starting point is 1:15 to 1:17 ratio (1 gram of coffee for every 15-17 grams of water).
  • Experimenting with ratios can help find the perfect balance.

4️⃣ How Wonderbean Balances Bitterness

At Wonderbean, we focus on creating a smooth, flavorful coffee experience by balancing all these factors.

✅ Medium Dark Roasting

  • Stops roasting before too many bitter phenylindanes develop.
  • Brings out deep chocolate and caramel flavors while maintaining a smooth finish.

✅ High-Altitude Arabica Beans

  • Arabica beans naturally contain less caffeine than Robusta, leading to a more balanced bitterness.
  • High-altitude growing conditions slow down bean development, resulting in more complex flavors and a smoother taste.

✅ Washed & Sun-Dried Processing

  • Washed processing removes excess bitter compounds from the bean.
  • Sun-drying allows natural sweetness to develop, creating a well-rounded taste.

✅ Proper Brewing Recommendations

  • Medium grind for balanced extraction (not too fine, not too coarse).
  • Correct water temperature to avoid scorching the coffee.
  • Ideal brew time to prevent over-extraction.

By following these principles, Wonderbean’s coffees deliver a rich, full-bodied experience with a perfect balance of boldness and smoothness—never overly bitter. ☕✨

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