By Chase Lemos, Nuova Ricambi USA
Most grinders are workhorses and work well for many years, but they do need some help along the way in the form of some basic maintenance. Many technicians will perform preventative maintenance on the espresso machine and then head out to the next job and the grinder can end up being forgotten. Below, you will find some of the maintenance that keeps grinders running at peak performance.
At least once a quarter, oil build-up will have to be addressed (often more frequently) and, as long as you are there for a PM, you may as well bill for it. It helps the account keep their coffee tasting its best and it helps add another 15 minutes onto your bill, it really is a win-win.
Remove the hopper, it can be wiped out with a wet towel or, if build-up is significant, dip the towel in backwashing detergent, but make sure to rinse the hopper thoroughly afterward. This will help remove the putrid oils that cling to the inside of the hopper. These oils don’t taste very good and will affect all the coffee they come into contact with, not to mention that the customer can see how grimy the hopper is and may choose to purchase their coffee elsewhere if the build-up gets too bad.
Remove the burr chamber, in a Mazzer this is done by unscrewing the grind adjustment collar. Using a steel brush and moving with the directions of the threads, carefully brush out any stray coffee particles and oils that may have begun to accumulate from the upper and lower threads. Next, wipe the threads using a soft cloth to remove any remaining oils that have built up. Note that the threads in the grind chamber cannot be repaired, if the adjustment collar gets cross threaded during reassembly, the grinder can be ruined.
Take a shop vacuum, if you have one available, and suck out any detritus that may be hanging around the grind chamber. While you do that, take note of the burrs - how sharp are they? How grimy are they? Most technicians know their accounts well and have a good idea of how often the grinder burrs will need to be replaced. However, if the account is a new one, it is a good idea to take a good look at how the burr teeth are holding up. This sounds basic, but by recognizing that the burrs are dull you may just save an emergency call form that barista who can’t set the grind at 5 am.
If your grinder has a doser on it, vacuum out any spare coffee and wipe out the doser glass the same way you did with the hopper. The doser frequently gets forgotten, taking time to make sure that the doser is clean will help ensure good coffee flavor. While you are cleaning the doser, take note of the various springs that you come in contact with. If any of them feel weak, you may change them out there, or make sure that you bring one with you when you come back next. This can also save you a call because the doser broke in the middle of a rush. You do not have to replace every spring every time you visit a customer, but if you are able to replace a worn part before it fails, it can save you a headache later. On the doser, the pin that catches the gear (the part that keeps the doser from moving backwards) can bet built up with coffee oil over years of use. If that happens, the pin may stick in the recessed position and then will not catch on the gear and will cause the grinder to fail to advance. If you get the doser far apart enough to get to that part, it is a good idea to clean it as best you can to prevent it breaking down in future.
Finally, reassemble the grinder and run a dose of Puly Grind through the burrs to help remove any oils that have built up on the burr teeth. This is something the cafe can do weekly on their own (and is another product you can bring them every time you visit). Using this cleaner is often poo-pooed as being useless. It isn’t. Preventing the oil build up in the nooks and crannies of your burrs will keep them functioning as they were designed to. If the oils build up, you will taste it in the coffee and you will notice a slower and less consistent grind. (As some already know, you can use instant rice to clean grinder burrs with decent effectiveness, however, many manufacturers state that the use of rice to clean the burrs will void the grinder warranty. Do not void your customer’s warranty by using the wrong cleaning product).
Finally, simply wipe down the outside of the grinder removing any coffee dust that is clinging to the surface. This simple act leaves the work station looking better than when you arrived and is always appreciated.
It’s good to remember that a well-maintained grinder is one of the keys to great coffee. You can leave the espresso machine in perfect condition, but if the grinder is dirty, has dull burrs, or just needs a little TLC, you can be setting your account up to serve poor quality coffee. When approached from this perspective, your account will welcome the extra work.