Measure the whole shot
A fast shot only means something when you measure the endpoint. Twenty seconds to 20 grams is not the same recipe as 20 seconds to 50 grams. Record the dose, yield, and time in the same way each time.
Fix a shot uses time as a broad flow clue. It does not measure extraction yield directly.
Make one finer change
Keep the dose and target yield fixed. Move one small grinder step finer. Use the same preparation routine. The next shot should take longer because the grind changed, not because you stopped at a different yield.
Do not jump several settings. If the shot stalls or becomes uneven, move back toward the earlier setting and check how you spread the coffee.
- Same dose.
- Same target yield.
- One small grinder step finer.
- Same preparation routine.
When to stop grinding finer
Spraying, one-sided flow, or sour and bitter together call for a preparation check. Research and practical guidance warn that finer settings can make uneven flow harder to repeat.
A pressurized basket, pre-ground coffee, or large grinder steps can limit this test. Follow the machine and grinder instructions and note that limit.
Guide limits
This guide uses your measurements and observations. It does not test your equipment.
Enter your shot. Get one next step.
Fix a shot fills in this guide's taste, flow, and time pattern. Replace them if they do not match your shot. Enter the dose and yield from your actual shot, then check every field before you continue.
Open Fix a shot with this symptom →Common questions
When should I start the timer?
Use one starting event every time. Pump activation is common. The exact choice matters less than using the same choice for each shot.
Can I add more coffee instead of grinding finer?
You can, but dose changes the recipe and how full the basket is. Keep dose stable for the first test unless it is outside the basket’s range.
Is a fast shot always sour?
No. Flow and taste are different notes. Record both.
Sources and their limits
- Manufacturer guideDialing In Made EasyRancilio Group North America · checked 2026-07-22(opens in a new tab)
Supports recording dose, beverage mass, time, and taste and using grind as a controlled lever; its time bands are reference bands, not pass-fail standards.
- Peer-reviewed researchSystematically Improving Espresso: Insights from Mathematical Modeling and ExperimentMatter / University of Huddersfield research portal · checked 2026-07-22(opens in a new tab)
Supports the nonuniform-flow warning at very fine settings; it does not diagnose an individual puck.
- Peer-reviewed researchInfluence of Flow Rate, Particle Size, and Temperature on Espresso Extraction KineticsFoods · checked 2026-07-22(opens in a new tab)
Supports interactions among flow, particle size, temperature, and brew ratio; it does not provide a universal sensory recipe.