Commercial Coffee Machine Maintenance: What I Learned by Setting My Roaster on Fire

Some lessons you only need to learn once.

Early on, I set the flue of my first roaster on fire. I hadn't thought to clean it out, and chaff and coffee oils had been quietly building up inside. When it caught, I did what any calm professional would do. I ran out of the shed screaming.

I'm not good in an emergency. My husband is. I rang him, and he asked, very calmly, whether I'd turned off the fan that was blowing air onto the fire. I hadn't. "Well, get back in there and do it," he said. So I did, and the fire went out.

These days, on our Diedrich CR70, the chaff collector is emptied every six roasts and the ducting to the afterburner is cleaned monthly. No exceptions. It never makes the tasting notes, but it's part of why the coffee tastes the way it does.

Your café machinery deserves the same discipline. It probably won't catch fire. It'll just quietly make worse coffee until the day it stops altogether. And every kilo of coffee you can't sell is over $300 missing from the till.

Here's the schedule I recommend.

Machine servicing

• More than 16kg a week: service every eight months.
• Under 16kg a week: once a year.

Outside the city, a same-day tech is rare, so staying ahead matters even more. Regular visits also keep your tech familiar with your site. They'll catch worn seals, tired shower screens, a failing flow meter, dropping steam pressure, or a pump on its way out, all before they turn into an emergency call-out.

Grinder burrs

Great coffee starts at the grinder, and burrs wear out.

• Mazzer Mini (64mm flat burrs): replace at around 400kg.
• Mazzer Kony (63mm conical burrs): replace at around 600–750kg. Conical burrs wear more slowly than flat ones.
• Compak flat burrs (F8, E8, F10, E10): replace every 600kg.
• Compak conical burrs (Master series): up to 1,000kg.

These are guides. The blend you use and your grind setting both affect wear, so watch for the signs below.

Signs your burrs are going:

• Grind time creeps up. If 3.4 seconds used to give you 21g and now it takes 4.2 seconds, the burrs are blunting. Check your orders since the last change to confirm.
• The shot won't settle. You keep grinding finer, but the extraction time only holds for a shot or two, and the coffee smells and tastes flat. Dull burrs produce an uneven spread of particle sizes, so water finds easy paths through the puck.

Water filtration

Espresso is around 90% water, so your filtration matters as much as your beans.

• Standard filters: change every 10,000 litres or six months, whichever comes first.
• Reverse osmosis systems: service every six to eight months, especially in towns on hard bore water. Blocked sediment filters can starve the machine of water. Some systems bypass the filters when they're full, sending unfiltered water straight through and raising the TDS.
• Remineralise RO water. Pure RO water is too soft for good extraction and can be harsh on boilers.
• Target: the Specialty Coffee Association recommends brewing water of around 150 ppm TDS.
• Date every cartridge. When coffee starts tasting flat and you're hunting for the cause, you'll know straight away whether the water is a suspect.

Daily cleaning

A dirty machine will ruin the best coffee, whoever's on the tools.

• Backflush the group heads daily with Cafetto Espresso Clean. Learn your machine's automatic cleaning cycle, and call us if you're not sure how.
• Brush or vacuum out the grinder daily, or weekly at the very least. Use a brush, vacuum or dry cloth only, never water or cleaning products. Old grounds and coffee oils left in the burr chamber and chute go stale fast and taint every shot.
• At close, return the beans to the bag or an airtight container, then wash and dry the hopper.
• Drop and clean the shower screens weekly.

Need a hand?

For help finding a machine technician, or for advice, call us on 1300 389 487. Not a wholesale customer yet? Set up your account here.