Turn the adjustment dial while the machine is grinding — not when idle, otherwise you risk damaging it. Take small steps, then test several shots. Too fine = bitter, too slow. Too coarse = watery, too fast.

How do I adjust the grind size on my fully automatic machine?

Turn the adjustment dial while the machine is grinding — not when idle, otherwise you risk damaging it. Take small steps, then test several shots. Too fine = bitter, too slow. Too coarse = watery, too fast.

Why that is

Even with a fully automatic machine, the grind size is one of the most important levers for taste. Compared to an espresso machine, you have less control — most fully automatic machines offer 3–8 settings instead of stepless adjustment. But even a difference of one step can noticeably change the coffee.

Important rule: Only adjust during the grinding process. Most fully automatic machines have a ceramic or steel grinder with interlocking burrs. If you turn the adjustment dial while it’s at a standstill, the burrs can jam or get damaged. Therefore: start a shot, and while the machine is grinding, adjust the dial by one step.

Adjusted too fine:

• The coffee tastes bitter, harsh, over-extracted.
• The shot runs very slowly or just drips.
• The machine audibly works harder.
• Solution: adjust it one step coarser.

Adjusted too coarse:

• The coffee tastes thin, watery, sour.
• The shot runs through very quickly (under 15 seconds).
• Little or no crema.
• Solution: adjust it one step finer.

Adjusted correctly:

• The shot runs in 20–30 seconds.
• Stable, golden-brown crema.
• Balanced taste — neither bitter nor sour.

After the adjustment: Wait for at least 2–3 shots before judging the taste. The first cup after the change still partially uses the old coffee grounds and is not representative.

When to readjust: With new beans (different roast = different optimal grind size), after a long period of non-use, or if the taste has changed.

In practice at Green Wall Coffee

At Sophienstraße 27, we work with espresso machines and stepless grind adjustment. For guests with fully automatic machines, I say: the grind size is your most important lever. Try one step finer and one step coarser — the difference is amazing, even on a machine with only 5 settings.

Related questions

• Which beans are best for fully automatic machines?
• Why does the coffee from my fully automatic machine suddenly taste bad?
• Why should you grind coffee fresh?

Stop by Sophienstraße 27 — Mon–Fri 8am–5pm, Sat 10am–5pm.