Water makes up 90–98% of your coffee. An expensive machine cannot fix bad water. The proper order of investment: grinder first, then water, then beans, then the machine.

Why is water more important than the machine?

Water makes up 90–98% of your coffee. An expensive machine cannot fix bad water. The proper order of investment: grinder first, then water, then beans, then the machine.

Why that is

The math is simple: an espresso is 90–92% water, and a filter coffee is 98–99% water. Water isn’t just a vehicle — it’s the dominant ingredient. And no machine in the world can turn bad water into good coffee.

A 3,000-euro espresso machine with PID control, dual boilers, and a rotary pump delivers incredibly precise temperature and stable pressure. But if the water is 20 °dH hard, loaded with limescale, and packed with carbonate hardness that completely neutralizes coffee acidity, your espresso will still taste flat and muddy. That exact same machine, running filtered 6 °dH water, will deliver a completely different shot — complex, fruity, and sweet.

Conversely: a basic 300-euro entry-level machine paired with excellent water, a top-tier grinder, and fresh beans can produce phenomenal espresso. The machine’s only job is to deliver 9 bars of pressure and 92–94 °C water — and plenty of cheap machines can do that adequately.

The golden order of priorities among baristas:

1. Grinder — dictates the uniformity of your extraction. Without a good grinder, good results are impossible, regardless of everything else.
2. Water — dictates which flavors are actually extracted and how the coffee tastes. A 20-euro pitcher filter will often improve your cup more than a 500-euro machine upgrade.
3. Beans — freshly roasted, high quality. No amount of equipment can salvage stale or poorly roasted beans.
4. Machine — provides pressure and temperature. As long as it delivers those two things, the machine is actually your smallest lever for flavor.

This order of priorities often shocks beginners, who typically blow their entire budget on a shiny machine and then wonder why their coffee tastes nothing like the café. The reason: their grinder cost 50 euros, their water is unfiltered from the tap, and their beans are three months old.

In practice at Green Wall Coffee

At Sophienstraße 27, when we built the café, we installed our water filtration system first and picked our grinders second — before the espresso machine was even ordered. When guests ask me about upgrading their home setup, I tell them: if you have a 500-euro budget, spend 200 on a grinder, 50 on a water filter, and 250 on the machine. Don’t blow 500 on the machine and ignore the rest.

Related questions

• How important is water quality for good coffee?
• Do I need a water filter for my coffee machine?
• What is the most important investment: machine, grinder, or beans?

You can find more in-depth information in the article How to make perfect espresso. Or drop by Sophienstraße 27 — Mon–Fri 8am–5pm, Sat 10am–5pm.