Most agree that the commercial espresso grinder plays a significant part in the execution of the perfect espresso shot. For those of you who are new to commercial espresso grinders, the greatest expectation you should have for your commercial coffee grinder is for it to evenly cut, not crush, each coffee bean.
The less heat your commercial espresso grinder generates, the less effect it will have on the composition and character of your coffee. The more heat your grinder generates, the more your coffee, and its flavor, will change. Heat caused by friction will undoubtedly happen; however, limiting heat is what espresso manufacturers attempt to achieve especially in their precision models.
Before you begin shopping for a commercial coffee grinder, we recommend you first identify your grinding volume.
In this article we will discuss burrs, grind adjustment, dosing; and other important features to consider when selecting a commercial espresso grinder.
There are two fundamental reasons why a grinder will overheat. It is being used beyond its designed capabilities, or the grinding burrs are dull.
There are three materials used in the manufacturing of burrs. They are ceramic, steel, and titanium alloy.
disperse heat well and are long lasting. Utilized less than steel, ceramic burrs are found in on-demand espresso grinders such as the La Marzocco Swift or in super-automatic espresso machines, such as the Evolution ASP by Franke Coffee Systems. Ceramic burrs are prone to shattering and can be easily damaged if foreign objects find their way into the hopper with your coffee beans.
are the most common material burrs are made from because of its affordability. If over used, steel burrs will easily heat. Manufacturers of espresso grinders use a hardened steel to increase durability and to reduce some heat. Larger volume grinders will employ larger burrs to increase grinding volume. Steel burrs do not wear as well as burrs made from other materials.
last almost three times longer than steel burrs, disperse heat well and are not easily damaged. Also, the cutting surface of the titanium burr remains consistent longer. Yes, you guessed right, the titanium burr is the most costly. You can find titanium burrs on grinders such as the Nuova Simonelli Mythos Plus and Mythos Clima Pro.
are more affordable and more commonly used in commercial grinders. When considering a grinder, remember the burr size should increase as the grinders volume rises.
are manufactured utilizing steel and the shape tends to aid the burr in the longevity of its sharpness. A conical burr grinder will also typically be a low RPM grinder. Like the flat burr, the conical burr comes in larger sizes to accommodate greater grinding demands.
At some point or maybe even at several intervals during your day, the composition and characteristics of your coffee may change and a grind adjustment will become necessary to maintain product consistency. Coffee will change because of fluctuations in its environment. The day starts cold but later heat and humidity rise. Another influence that will transform your coffee is heat that can be generated from your grinder.
Grind adjustments should be made when your coffee consistently pours outside of the established brewing time for your specific flavor profile.
is the easiest way to make grind adjustments.The adjustment knob is located away from the burrs. As you rotate the fluid knob, you affect a lever that moves the lower burr to or away from the upper burr collar. There an exception to this found in machines such as the La Marzocco Swift which the adjustment is made to the upper burrs using a worm gear for fine control. The fluid micrometric knob gives you the ability to influence your grind with easy precision.
is similar to the micrometric knob however the adjustment moves the upper burrs instead of the lower. This type of adjustment found in grinders such as the Kryo by Rancilio utilizes a knob with a reduced gear. Many consider this type of adjustment micrometric and it is very specific, however the knob is not fluid. A stop pin must be held during adjustment and secured into a fixed orifice to capture the setting. The adjustment knob is more precise than the stepped and stepless collar because the reduced gear allows for more exactness in the adjustment.
is found on top of the stationary burr holder and is fluid like the micrometric knob. The upper burr holder hovers or sits on springs situated over the lower burrs. As you turn the collar, the burrs are moved closer or further away from the lower burrs allowing for a finer or coarser ground. Many find the stepless collar to be clumsier to use compared to the smaller micrometric knob.
Stepped Collar is part of the stationary burr holder and when adjusted the entire burr holder is moved and is held in place by a stop pin. To adjust your grind, you must hold the stop pin down, this allows you to freely move the adjustment collar. You then release the stop pin to lock the collar into a fixed orifice or position. The stepped collar adjustment is less accurate because it does not allow you to set the grind in any other positions except for those that have been predetermined in its design.
There are two options for dosing grounds: Electronic and Manual
Coffee is ground into a dosing chamber and then manually dispensed into a portable filter basket for tamping and brewing. The dosing is accomplished by a lever, that when pulled, disperses a measured amount of grounds into the filter basket. One pull or throw for one shot, two pulls for two shots. A measurement star is used to adjust and define the amount of grounds to be released for each pull/throw. Average maximum weight for a pull/throw, using a dosing chamber, is nine (9) grams.
For the grinder with a dosing chamber to dispense accurately, it is necessary for the dosing chamber to be at least half full with grounded coffee. At the end of the day, any unused coffee should be thrown out. Unfortunately, even with the dosing chamber filled, accurate dosing can still be difficult to achieve if air pockets exist or if grounds have settled within the dosing chamber.
Electronic Dosing (On-Demand) Coffee is ground at the time of order and is dispensed directly into the portable filter basket. Electronic grinders will offer two (2) to three (3) selections; and typically, an additional option is also available for the barista to operate the grinder manually. Most electronic grinders will have an LCD display and key pad for uncomplicated programming. Programming the measurement of grounds to be dispensed is defined by time. There are some exceptions to this such as the Swift grinder by La Marzocco which is adjusted by a coffee height stop switch. Most grinders will begin grinding when the portable filter assembly is engaged, others such as some Mazzer grinder models will begin when a button is pressed.
Because the dosing chamber must be filled to dose accurately, some grinders will offer an automatic grind and fill feature. When the level of coffee grounds reaches a minimal amount in the dosing chamber, the grinder will automatically refill the dosing chamber with fresh grounds. Grinders with this feature are referred to as automatic grinders. Do not confuse this with electronic or on-demand style grinders.
Grinders with dosing chambers that do not have the an automatic fill feature are referred to as semi-automatic or standard grinders. The dosing chambers is filled when a switch is manually activated.
Dynomometric Tamper is found mounted on the front of the grinder. The dynomometric tamper is designed to deliver the same pressure release. Although industry standards define tamping pressure to be at thirty pounds, the dynomometric pressure can be adjusted. The tamper must be serviced regularly for it to retain its accuracy. The mounted dynomometric tamper is offered by manufacturers such as Macap and Nuova Simonelli.
The automatic tamping mechanism is found in the grinders front housing and while the grinder is dispensing grounds, an auger forces the coffee down into the filter basket, tamping and polishing the grounds simultaneously. As the coffee level rises, the auger gradually moves up until it reaches a predetermined level set by the barista, engaging a microswitch, automatically shutting off the grinder. The auger continues to spin for a final polish of the grounds. Automatic tamping is found on machines such as the Swift and Vulcano Swift by La Marzocco.
A commercial espresso grinder can generate enough heat to even re-roast beans resulting in an unpleasant taste.
Manufacturer’s are always looking for better ways to disperse heat. Low RPM grinders are designed to efficiently grind at lower revolution, resulting in less friction. The Low RPM grinder is favored by those who are attracted to precision brewing and desire to control all aspects of the brewing process; in this case, the heat created by grinding and its effect on the coffee’s flavor profile.
This feature, which is not commonly found on espresso grinders, maintains burr temperature through heating and cooling of the burrs. This is accomplished by maintaining the burr chamber at a set temperature so when grinding the climate does not change. This feature is particularly attractive to those who work with roast profiling and want to avoid the affects of heat variation in product delivery. The the thermally stabilized attribute may be found on grinders such as the Nuova Simonelli Mythos Clima Pro.
Additional ways manufacturers have found to keep burrs cool is venting as well as repositioning burrs away from the grinding motor.
Hoppers will generally be sized according to the grinders operating volume. If hopper size is important to you, we have a PDF spread sheet that you can view below comparing the individual features of some of the more common commercial coffee grinders.
Dual hoppers can be found on some espresso grinder such as the La Marzocco Swift and Mahlkoenig K30. Dual hoppers are not a common feature.
Sometimes a lot of emphasis is placed on the grinder’s motor; however, we have found that generally the size and construction of the burrs will be a better indicator of the grinder’s production capabilities. Typically, grinding motors do not usually fail; however, they can with over use. The wattage of the motor can be a good indicator of the grinder’s volume. The higher the wattage, the higher the volume.
Remember that your grinder is a key component to making good coffee.
To find the best coffee grinder for you, always consider how much you will be using your grinder to avoid purchasing one that is too small. Many manufacturers will boast about the abilities of their grinders, but as a consumer, start with the size of the grinding burrs and the wattage of the motor, then consider and compare features of those grinders which meet your requirements.
If you are considering purchasing a used commercial grinder, remember the expectation of a grinder is to last as long as the espresso machine. Although, there are many opinions on how long an espresso machine should operate in a commercial atmosphere, we recommend not exceeding seven years. Are advise is for you to always consider a new espresso grinder. Used grinders are just that and any defects will not present themselves until the grinder is placed into operation.
Unlike the commercial espresso machine where maintenance is required whether the machine is operated to its full potential or not, you can not over buy when it comes to the grinder. Even if you do not use your grinder to its maximum volume, the consequences will only be that the components such as the burrs and motor will have a longer life span and your maintenance will not increase but rather decrease.