When someone tells us their espresso tastes different every day, they're usually already looking at new machines. Before we talk about that, we ask about the grinder. More often than not, that's where the answer is.
It makes sense once you think about what each one does. The machine brings water at the right temperature and pressure, and a good one does it the same way every time. The grinder decides how that water meets the coffee. As La Marzocco puts it, the grind is what makes the espresso flow fast or slow. Profitec puts it even more plainly: even the best espresso machine can only perform as well as the grinder it's paired with.
A grinder that struggles shows itself in small ways. The first shot of the morning tastes stale because yesterday's coffee was still sitting inside it. A setting that worked on Monday doesn't work on Thursday, and the step between sour and bitter is too big to land in between. Coffee changes as it ages and every new bag needs a little adjusting, so a grinder that lets you make small, precise changes turns that from a chore into part of the fun.
This is where today's home grinders have come a long way. Single dose grinders such as the Mahlkönig X64 SD or Eureka's ORO Single Dose are designed to keep almost nothing inside, so you grind exactly what you weighed and nothing from yesterday. Others, like the Eureka Mignon range, let you adjust the grind continuously rather than in fixed steps. And at the top end, grinders like Weber Workshops' Key bring burrs to your kitchen that would not look out of place in a café.
None of this means your machine doesn't matter. It means that if you have a budget for an upgrade, it's worth knowing where it will make the biggest difference.
The best way to see it is with your own coffee. Bring a bag of beans to our showroom in Tsuen Wan and we'll pull the same coffee on the same machine through two different grinders. It tends to be a very convincing sip. We see people by appointment, any day of the week: WhatsApp +852 9476 9677.