Read the concept, complete the knowledge checks, then practice the same skill in Coffee Lab.
Dial-in: change one variable, then taste.
Use this mini trainer to see how grind, dose and time move you away from or toward the prototype house zone. This is a simplified learning model, not a replacement for tasting.
Diagnosis sequence
Check the recipe target
Know the intended dose and extraction window before diagnosing.
Observe flow and time
Fast = usually too little resistance. Slow = usually too much resistance.
Taste the espresso
Sour/thin can point toward under-extraction. Dry/harsh/bitter can point toward over-extraction.
Adjust the grinder first
When dose is correct, grind is usually the cleanest day-to-day calibration variable.
Record the stable point
Consistency across the shift requires the team to share the same target.
Dial-in Calibration Lab
Solve station calibration issues and bring grind, dose and extraction back into the target zone.