The Coffee Journal

The grinder decides how consistent your espresso is before the machine ever touches it. Two cafés can buy the same espresso machine and the same beans and still serve very different coffee, because one grinder holds its dose and its grind steady through the day and the other does not. Here is what to look for in a grinder, and the habits that keep it performing.

Dose by weight, not by time

A timed grinder runs for a set number of seconds, so the amount of coffee that lands in the basket changes when the beans change: their density, their age, even the humidity in the room. A grind-by-weight grinder has a scale built in and stops when it reaches the dose you set. A gram or two either way can noticeably change how fast the shot runs and how it tastes, so a steady dose is the first thing to get right.

It helps to be clear about what this does. Grinding by weight improves consistency and saves your barista weighing every dose. It does not replace good technique, and a well-set-up timed grinder, checked regularly on a scale, can work well in a busy bar.

Tamping: the other variable

Once the dose is steady, the next source of variation is the tamp. Pressure and levelness change from barista to barista, and from the first shot of a shift to the last. An automatic tamper such as the Puqpress applies the same level tamp every time, with the force set by you rather than by whoever is on the bar. Suppliers also point to a health benefit: tamping by hand is a repetitive motion, repeated hundreds of times a day in a busy café, and automating it takes that strain off wrists and shoulders.

Keeping it consistent through the day

Even a great grinder needs a little attention. A few habits make the difference between espresso that tastes the same at 4pm as it did at 8am, and espresso that doesn't.

• Taste a shot at the start of every shift. Beans and the room change overnight, and the setting that worked yesterday may not be right today.
• Weigh the dose and the yield, not just the time. Time on its own can hide a problem. A weighed dose and a weighed shot tell you what is really happening.
• Purge after you adjust. Every grinder holds a little ground coffee inside, so a change in setting does not show up straight away. Run a few grams through before the next shot you serve. The same goes for the first shot of the day after the grinder has sat overnight.
• Expect the setting to move. Humidity and temperature change how beans behave, so a setting that suits the morning may need a small nudge later. Keep a simple log of the setting and the shot time, so the team can see the pattern.
• Clean it on a schedule. Old grounds and oils build up in the chamber and chute, and they end up in the next cup.

Burrs wear, and it shows in the cup

Burrs do not fail suddenly. Their cutting edges round off gradually, and the first sign is usually that the grinder is harder to dial in: shots drift, the setting needs constant correction, and espresso tastes both sour and bitter. A grinder that runs louder or hotter than it used to is another hint.

How long a set lasts depends on volume and on the coffee. A busy bar can easily replace burrs once or twice a year, and light roasts, being harder, wear them faster. Larger-diameter commercial burrs spread the wear over more cutting surface. When the time comes, replace both burrs together as a matched set, recalibrate, and let the new burrs settle in before judging your shots. This is a job for your service plan, not something to leave until customers notice.

Choosing the right grinder

• Match it to your volume. A grinder for a hotel breakfast room is not the grinder for a café with a queue at 8am.
• Decide how you want to dose. By weight if consistency across a changing team matters most, by time if you prefer a simpler set-up and will check it regularly.
• Look at the burrs. Size and type affect speed, consistency and how often they need replacing.
• Think about cleaning. If the chamber is hard to reach, it will not get cleaned.
• Ask about backup. Who services it, how fast they respond, and whether your team gets trained to use it properly.

Khanya supplies grinders and the Puqpress alongside espresso machines, water filtration and boilers, and we look at the whole set-up rather than one piece of kit. Our earlier guide to what makes a great commercial coffee machine covers the machine side.

Sources: Clive Coffee on grind retention, dialling in and burr wear; Seattle Coffee Gear on grind-by-weight and timed grinders; Coffee Machine Depot on when to replace grinder burrs; Coffee Parts Australia on choosing replacement burrs; Buna Coffee on the Puqpress Q; Prima Coffee on timed grinding and grind by weight.