Coffee Tastes Bad - How to Fix

If your coffee doesn't taste right, here's how to diagnose and fix the issue.

Identify the Problem

Bitter Coffee

Possible Causes:

• Over-extraction (brewing too long)
• Grind too fine
• Water too hot
• Too much coffee
• Stale or dark roasted beans

Solutions:

• Coarsen the grind setting
• Reduce brew time
• Use less coffee
• Try lighter roast beans
• Check water temperature (ideal: 90-96°C)

Sour/Acidic Coffee

Possible Causes:

• Under-extraction (brewing too short)
• Grind too coarse
• Water not hot enough
• Not enough coffee
• Very light roast beans

Solutions:

• Fine up the grind setting
• Increase brew time
• Use more coffee
• Ensure machine is fully heated before brewing
• Try medium roast beans

Weak/Watery Coffee

Possible Causes:

• Not enough coffee grounds
• Grind too coarse
• Brew time too short
• Old or stale beans

Solutions:

• Increase coffee dose
• Fine up the grind
• Extend brew time
• Use freshly roasted beans (within 2-4 weeks of roast)

Burnt Taste

Possible Causes:

• Water temperature too high
• Coffee sitting on hot plate too long
• Dirty machine (old coffee residue)
• Very dark roast beans

Solutions:

• Check and adjust water temperature if possible
• Don't leave coffee on warming plate
• Clean your machine thoroughly
• Try medium roast beans

Metallic or Chemical Taste

Possible Causes:

• New machine not properly flushed
• Descaling solution residue
• Old or contaminated water
• Dirty water tank

Solutions:

• Run multiple rinse cycles through the machine
• Clean water tank with mild detergent, rinse well
• Use fresh filtered water
• Replace water daily

Stale or Flat Taste

Possible Causes:

• Old coffee beans
• Beans stored improperly
• Pre-ground coffee gone stale
• Machine needs cleaning

Solutions:

• Use beans within 2-4 weeks of roast date
• Store beans in airtight container away from light
• Grind beans fresh before each brew
• Clean machine thoroughly

Coffee Taste Troubleshooting Chart

Machine Cleaning Checklist

Regular cleaning dramatically improves taste:

Daily:

• ☐ Empty and rinse drip tray
• ☐ Wipe steam wand after each use
• ☐ Rinse portafilter and filter basket
• ☐ Empty coffee grounds container

Weekly:

• ☐ Backflush with water (espresso machines)
• ☐ Clean group head with brush
• ☐ Wash removable parts
• ☐ Wipe exterior

Monthly:

• ☐ Backflush with cleaning solution
• ☐ Deep clean brew group
• ☐ Clean grinder burrs (if applicable)
• ☐ Check and clean water tank

Every 2-3 Months:

• ☐ Descale the machine
• ☐ Replace water filter (if applicable)

Water Quality Matters

Water makes up 98% of your coffee. Poor water = poor coffee.

Recommendations:

• Use filtered water (Brita, inline filter)
• Avoid distilled water (can damage machines)
• Avoid very hard water (causes scale buildup)
• Change water daily for freshness

Bean Storage Tips

• Buy in small quantities (2-4 weeks supply)
• Store in airtight container
• Keep away from light, heat, and moisture
• Don't refrigerate or freeze (causes condensation)
• Use whole beans and grind fresh

Still Not Right?

If you've tried these solutions and your coffee still doesn't taste right:

1. Try a different coffee bean brand
2. Consider a professional machine service
3. Chat with us for personalised advice

We're coffee lovers too and happy to help you dial in the perfect cup!

Updated on: 27/01/2026