Why is my espresso sour?

Sour espresso indicates under-extraction. The water rushed through too quickly. Solution: grind finer to slow flow and increase extraction.

Why is my espresso bitter?

Bitter espresso indicates over-extraction. Water spent too long in contact with grounds. Solution: grind coarser to speed up flow.

Channeling occurs when water finds fast paths through the puck, leaving most grounds under-extracted. Fix with better puck prep using WDT (Weiss Distribution Technique) and even tamping.

Espresso Dial-In Assistant

DIAL.ASSIST Interactive

Current Recipe (Optional)

Dose g

Yield g

Time sec

What's Wrong With Your Shot?

Select all that apply. Be honest—multiple issues are common.

Recommended Adjustments

tune

Select the issues you're experiencing above to get recommendations.

The Basics

Grind Finer

↑ Extraction, ↓ Flow rate, ↑ Body

Grind Coarser

↓ Extraction, ↑ Flow rate, ↓ Body

↑ Dose

↑ Strength, ↓ Flow rate, ↑ Body

↑ Yield

↑ Extraction, ↓ Strength, ↓ Body

↑ Temperature

↑ Extraction, ↑ Bitterness risk

Dial-In Order

Fix flow first. Get into 25-35 second range with grind adjustments.
Then taste. Sour? Finer. Bitter? Coarser. Make small changes.
Adjust ratio. If taste is close but strength is off, change yield.
Temperature last. Only if grind and ratio can't fix the issue.

science

One Variable at a Time

Change only one thing between shots. Otherwise you won't know what worked.

Quick Troubleshooting

Common problems and their most likely solutions.

Sour & Fast

Grind much finer

Classic under-extraction. The water is rushing through without extracting enough.

Bitter & Slow

Grind much coarser

Classic over-extraction. Too much contact time is pulling harsh compounds.

Sour & Slow

Check for channeling

Paradox indicates channeling—water finds fast paths, leaving coffee under-extracted.

Good but Weak

Reduce yield (shorter ratio)

Extraction is fine but concentration is too low. Pull a shorter shot.

Good but Intense

Increase yield (longer ratio)

Extraction is fine but too concentrated. Pull a longer shot to dilute.

Flat Despite Good Time

Check bean freshness

Stale beans lack aromatics and complexity. Time to buy fresh coffee.