Grind Size 101: The Easiest Way to Fix Bitter or Sour Coffee

Grind Size 101: The Easiest Way to Fix Bitter or Sour Coffee

If your coffee tastes off, nine times out of ten the fix is in your grind size. You don’t need a lab—just a burr grinder, a scale, and a simple process. Here’s how to diagnose sourness or bitterness and correct it quickly.

Understanding Coffee Extraction

Brewing pulls flavors out of ground coffee. Pull too little (under-extraction) and your cup tastes sour, thin, or salty. Pull too much (over-extraction) and it turns bitter, harsh, or drying. The right grind size exposes just enough surface area so water extracts sweetness, acidity, and aromatics in balance.

  • Coarser grind → larger particles → water extracts less (drains faster).
  • Finer grind → smaller particles → water extracts more (drains slower).

How to Dial in Grind Size Quickly

Dialing in your grind doesn’t have to be complicated or intimidating. By keeping everything else constant—your brew method, water temperature, and ratio—you can focus solely on grind adjustments and taste the difference one change at a time. This simple process takes the guesswork out of brewing and helps you find that sweet spot between sour and bitter.

The Three-Brew Dial-In Method

  • Baseline brew: Use your normal recipe (ratio, water temperature, method). Taste and write one note.
  • Adjust grind only:
    • If it tastes sour/thin → go one notch finer.
    • If it tastes bitter/astringent → go one notch coarser.
  • Confirm: Brew again with the new grind. Repeat in small steps until balance is achieved.

Keep ratio and water constant so you can isolate the effect of grind size.

Visual Grind Size Guide

You don’t need a microscope—just visual cues:

  • French press: coarse—think breadcrumbs/kosher salt
  • Drip/Pour-over: medium—like table salt or sand
  • AeroPress: medium-fine—just shy of powdered sugar
  • Espresso: fine—powdery, clumps when pinched

Different grinders label settings differently, so rely on taste and timing, not just numbers.

Coffee Brew Times for Perfect Extraction

Timing can help diagnose extraction problems:

  • Pour-over: A single-cup brew should finish around 2:45–3:30. Too quick (2:00)? Too coarse. Too slow (4:00+)? Too fine.
  • French press: 4:00 steep is a solid starting point. Longer times can add bitterness.
  • AeroPress: 1:30–2:00 works for most recipes.

Coffee Brewing Technique Matters Too

Even with the right grind, technique plays a big role:

  • Bloom grounds for 30–45 seconds to release CO₂.
  • Pour evenly in concentric circles during pour-over—avoid blasting the sides.
  • Stir or swirl gently mid-brew to promote even extraction.

Quick Troubleshooting Guide

  • Sour + fast brew: Go finer and pour slower.
  • Sour + slow brew: Stir gently or go slightly coarser.
  • Bitter + silty: Go coarser or switch to a thicker filter.
  • Hollow flavor: Increase dose or raise water temp (up to ~205°F).

Why a Burr Grinder Is Essential

Blade grinders chop unevenly, producing dust (fines) and boulders. Fines over-extract (bitter) while boulders under-extract (sour)—often in the same cup. Burr grinders crush beans evenly, unlocking clarity and sweetness. Manual burr grinders are affordable, quiet, and perfect for apartments.

Adjusting Grind Size for Different Coffee Beans

  • Light roasts: Denser, often need a finer grind or longer brew to extract sweetness.
  • Dark roasts: More soluble, usually better slightly coarser with cooler water.

When switching beans, expect to adjust your grind by 1–2 clicks.

Keep a Simple Brew Log

Track method, ratio, grind step, time, and tasting notes. Within a week, you’ll have a reliable reference for how to brew your favorite cup consistently.

Experience Better Brews with Savor Coffee

Great brewing starts with the right beans. At Savor Coffee, we source the finest single origins and blends, then roast in small batches to bring out balanced flavor in every cup. Whether you’re brewing French press, pour-over, espresso, or cold brew, our coffees are crafted to help you savor the ritual.

Ready to give your grinder something worthy? Explore Savor Coffee’s full collection and taste the difference proper extraction makes.

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