Bitter Truths: Why Your Coffee Tastes Bad and How to Fix It

You spent good money on your beans. You followed the recipe. You even bought a scale.

But the coffee? It tastes bitter, sour, dull — just… off.

You’re not alone. Most home brewers run into disappointing cups from time to time. The good news? It’s usually fixable.

Here’s how to decode the bad taste in your brew — and what to do about it.

Bitterness: The Most Common Complaint

Bitterness is one of the most common issues, especially in espresso or dark brews.

It usually means over-extraction — when the water draws out too much from the grounds.

Fix it:

Grind coarser to slow the extraction
Reduce brew time or lower the water temperature
Check your dose — too much coffee can lead to bitterness too

Sourness: Not Enough Extraction

If your coffee tastes sour, acidic, or “sharp,” the water probably didn’t pull enough flavour out. This is under-extraction.

Fix it:

Grind finer to increase extraction
Brew a little longer
Make sure your water is hot enough (around 92–96°C)

Flat or Dull Coffee? Could Be Your Water

If your coffee tastes muted or lifeless, check your water quality. Poor water can mask clarity and sweetness — or fail to bring out the bean’s best qualities.

Fix it:

Use filtered or bottled spring water
Avoid overly soft or overly hard water
Taste your water before brewing

(For more on this, read: Water Matters: How Water Quality Changes Your Coffee)

Staleness or Off-Flavours

If your coffee tastes “off,” dusty, or stale — even if you brewed it well — the issue could be with the beans themselves.

Fix it:

Use beans roasted within the last 4 weeks
Store them in an airtight container, away from light and heat
Don’t keep beans in the fridge or freezer unless fully sealed

When It’s Not You — It’s the Roast

Sometimes the beans just aren’t right for your taste. Some dark roasts carry inherent bitterness. Some light roasts taste sour unless brewed very carefully.

Fix it: