Coffee Calculators

Grind size & dialing in

Espresso Dial-In Calculator

Dial-in is a loop: weigh dose and yield, time the shot, then say whether it was sour, balanced or bitter. Sour and fast usually wants finer grind size; bitter and slow wants coarser. Channeling looks ‘fast and sour-bitter’ — fix the puck before you chase this output.

Inputs

Units
g
g
s

Your call on the last shot, not what Instagram says 1:2 should taste like.

Results

Suggested yield
36.0g
Grind direction
0

1 finer, -1 coarser, 0 hold

Time hint
28s

A target window centre, not a stopwatch religion.

The Result is indicative and educational. It does not constitute a design, a technical opinion or medical advice and does not replace calculations or verification by a person with the appropriate qualifications and authorisations. Before purchase, installation or use in practice – in particular in electrical installations – the Result should be verified by a qualified specialist. Details: Terms of Service, point 4.

Example products

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Calculation method

Sour means under-extracted: nudge yield about +8% so more water passes the puck. Bitter means over-extracted: trim yield about 8%. Shot time outside 25–32 s sets grind first (too fast → finer, too slow → coarser) and the time hint recentres on 28 s. If time is already in the window, grind still follows taste. Extraction yield still wants a refractometer — this page only steers the next shot.

Exact formula

Sour (under) → yield × 1.08; bitter (over) → yield × 0.92. grindDirection from time vs 25–32 s (too fast +1 finer, too slow −1 coarser); if time is in window, taste still sets grind. timeHint recentres to 28 s when outside the window. Limits: Basket, roast and water omitted; blond jets are prep, not a grind-direction oracle.

One variable per shot

Finer grind and a new ratio on the same pull teaches you nothing. The results show both levers; change grind or yield, not both, then taste.

Freshness

Beans still degassing will spray and fake a fast shot. Rest them, then dial. The degassing window tool is the calendar; this is the espresso loop.

Frequently asked questions

Sour but 32 seconds?

Could be too fine and still under-extracted if the roast is light, or channeling around a dense centre. Check the puck, then consider yield and water, not only grind.

Should I change dose?

Not on the same morning you are chasing grind. Fill the basket properly, lock dose, move grind and yield. Dose is a later lever.

What does grind direction 0 mean?

Time is in the 25–32 s window and taste is balanced. If the shot is sour or bitter with a normal time, grind still moves and yield nudges; 0 is not a licence to ignore flavour.

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