Macinazione: The Espresso Grinder and Why You Should Have One
Do I Need an Espresso Grinder?
If you have already checked out our Knowledge Base article on Coffee Grinders, you are ready to take the next logical step in understanding the story behind espresso grinders. One of the 4 (5 in our opinion) M's of espresso, the grinder, or Macinazione, is the most important equipment found in an espresso bar. Some may argue that it's all in the machine, but extracting proper espresso is truly a combination of many factors. A quality grinder is far more important than a multi-thousand dollar machine. To wit, I can take a $500 grinder and produce better espresso on a $100 entry-level espresso machine compared to the results I would get using pre-ground, or blade ground coffee on a $10,000 commercial machine. Coffee for espresso must be ground mere seconds before brewing, and no espresso machine will be able to compensate for a poor grind quality.
Why Is Espresso So Particular About Grind Quality?
Compared to other coffee brewing methods, extracting a proper espresso is a microcosm of the coffee culture in more than one sense. For our purposes today, that sense is time. For straight up ristretto or espresso shots, depending on your preference, you are brewing 0.75 to 2.5 ounces under 8.5 to 9 bars of pressure in 25 to 30 seconds. On an espresso machine with a commercial brewing system, such as the Nuova Simonelli Oscar or the Ascaso Steel UNO with PID, that pressure is created by the resistance offered by the ground coffee. To create the resistance the ground coffee must of course be very fine of a consistency that allows it to pack together tightly and facilitate proper water flow evenly throughout the bed of coffee. If the flow rate is too quick, a very weak extraction results. Too slow, such as barely dripping, and your coffee was just wasted on a bitter and undrinkable shot. With such a narrow window of opportunity, a seemingly minor change can make a world of difference. So not only must your grinder be capable of fine-tuning and adjustment to correct for poor extractions, it must also be built sturdily enough to tolerate the immense pressures placed on the moving parts. The grinders we sell that are built well enough to handle frequent espresso grinding can be found here.
How Do I Choose the Best Espresso Grinder?
This is usually the tough part of the discussion because it involves a comparison not only the grinders' abilities, but also how much you are willing to spend. If you are buying an espresso machine, and hadn't yet thought about the grinder, you need to factor it into your budget. The grinders we sell for espresso range from "acceptable" to "exceptional" for the home user. We have considered offering espresso grinders developed for commercial use that cost into the thousands of dollars, but they typically are tremendously large and not suited for placement into the average home kitchen. In general, home espresso grinders do a good job but are less expensive and tend to be slower, noisier, and messier. Ultimately it will be you who decides if the benefits outweigh the cost of a commercial grinder. So let's get down to what factors you will need to consider:
Conical or Flat Burrs?
Truly this is a debate that will never fully be settled, but the short end of the story is that conical burrs tend to produce a marginally better particle of ground coffee in the espresso range when paired with the proper stepless adjustment mechanism (read below). The difference really won't be noticeable unless you have invested sufficiently into your espresso machine as well. Conical burr grinders do tend to be much noisier compared to flat burrs until you get into the commercial grade units, but they also produce superior ground coffee for other preparations such as drip or French Press, though we recommend having a dedicated grinder for espresso.
Flat burr espresso grinders do run quieter than conical, and the grinders themselves usually weigh more. They typically have the burrs set into the equipment with heavier duty mounts/carriers. This has more to do with the way the beans are forced through the burrs and the directional pressures they exert upon the mechanism, so don't get hung up on the fact that some grinders use nylon or composite materials instead of brass or aluminum for the mounting.
Micrometric (Stepless) or Stepped Adjustment, and What is Macro/Micro?
To change your espresso grinder's fineness, you use one of these two methods to change the distance between the grinding burrs. Each has its advantages and drawbacks. The most traditional method, stepped adjustment, is found on grinders such as the Rancilio Rocky and typically involves turning the coffee bean hopper to the left or right one "click" at a time. Each of these clicks, or steps, corresponds to a numbered setting which makes it very easy to remember where to readjust your grinder after cleaning or when changing between different espresso blends. This is very convenient since different roasts require different grind settings and dosages. The drawback to the stepped adjustment is that there is always a gap between each setting. For each espresso machine and each espresso blend, there is one grind setting that is going to be a perfect match. It is possible that the perfect setting you are seeking lies between the numbered settings, in which case you have to adjust with your technique. The more numbered settings a stepped adjustment grinder has, the smaller the incremental gap and the better chance you have of finding the perfect grind setting.
Grinders such as the Ascaso I-2 or Nuova Simonelli MCI that feature stepless adjustment offer the ultimate level of precision and control over the fineness of the grind. Regardless of the design of various stepless grinders, the principle is the same: the smallest possible adjustment can be made because there is no gap or jump between settings. Obviously, the precision aspect of this is wonderful, but it comes with a couple caveats. The major drawback is that there is no marked setting for reference when you make adjustments, so you will not want to use this kind of grinder for different coffee brewing methods. The second shortcoming is that it can cause you to rely too much on adjusting the grinder rather than correcting any possible flaws in your technique, but to some, that is a pretty nice convenience during the learning process. We firmly believe that these objections are easily overcome by the excellent quality and consistency of these grinders.
A new technology found in the highly acclaimed Baratza Vario Grinder allows you to adjust your grind setting the same way you would a microscope. This is called Macro/Micro and involves dual adjusting mechanisms in the form of levers/arms. The lever on the right hand side allows you to choose the range of fineness (i.e. espresso) that you want to grind at, and the left lever allows you to adjust within that range just like the coarse/fine focusing wheels on a microscope. While it doesn't offer the "infinite" adjustments that a stepless grinder has, the Baratza Vario comes as close as you can get and also satisfies the complaint about referenced settings, since each adjustment has a marking on the face of the grinder. If you can fit this grinder into your home espresso budget, or you were originally considering a $1,000 dollar grinder and can tolerate the smaller capacity, we strongly suggest you consider the Baratza Vario.
Doser or Doserless?
The way a grinder delivers the ground coffee into your portafilter basket (or other container) is referred to either as a doser or doserless. Doserless grinders dispense the coffee directly into portafilter, giving them a natural advantage in low usage environments because of the shorter overall process. The grinder motor is activated a number of ways: a grind-on-demand pulse switch, a timer switch with reference points, or in the case of the Baratza Vario, programmable dosing choices (yes, this is sweet). Household grade espresso grinders do tend to be slightly messier and can sometimes put out the grounds in slight clumps. This doesn't get corrected until the commercial $900 and up range, so don't get discouraged if you notice it happening to you. Since you will still need to properly distribute these grounds once they are in the portafilter basket, you may as well rotate the basket if possible when grinding directly into it.
Espresso grinders with dosers, such as the Pasquini Moka, dispense grounds into a front-mounted hopper. Look inside an empty hopper and you will see a number of open compartments separated by "fingers" or vanes. When the hopper is full, each of these compartments stores equal amounts of coffee grounds. To get your grounds into your portafilter basket, you must pull on the dosing lever which moves the mechanism and "doses" fairly consistent quantities out of a bottom opening and into your basket, hence the name. This kind of setup offers an advantage for anyone who prepares many drinks in one setting, but can be a handicap for those one-a-day espresso lovers because the doser hopper has to be at least half full to get it to dispense uniform amounts of grounds. To create excellent espresso, you must grind immediately before brewing, so you don't want to grind all that extra coffee and let it sit for any extended time period. However, some people do use the doser for a different purpose: breaking up the clumps created by the household grade grinders. When the lever is pulled, it sort of throws the coffee out with a "thwack," breaking apart the clumps. Some people will continuously pull on the doser lever while the grinder is in operation. Sounds pretty involved to me, but hey, to each his own. Also, many times these doser grinders will have a stationary "tamper" mounted on the front, but don't think for a minute that this will get you out of buying a quality tamper. While these mounted tamps work well for true Italian single shot espresso, they are of little use for any other purpose.
Other Factors to Consider
For the average home user, the following attributes may not be as important, but for cafes and those espresso lovers willing to throw down some serious coin on a grinder, they are deciding factors between a host of premium equipment.
The size, or diameter, of the grinder burrs determines how much coffee can pass through with each turn at any given fineness setting. Most home grinder burr sets have a diameter between 40 and 50 mm. A primary grinder in a coffee shop features 60 to 75 mm diameter burrs, which are, of course, accompanied by a larger motor. This is important for high-volume shops because the grinder usually needs about 30 seconds of rest per 20 seconds of grinding to prevent overheating the motor.
Motor speed, in RPMs, is a term advertised heavily now that people understand that lower speeds impart less heat to the ground coffee beans, thus minimizing the chance of adding an outside burnt flavor to your espresso. It's important to understand that manufacturers of quality espresso grinders match the motor size, motor speed, and burr size to each other, so just because one grinder spins slower than another doesn't make it better.
Knowing the weight and physical dimensions of the grinder is necessary to finding a grinder that complements your kitchen countertop space. Some grinders go for style, and others give you big muscle in a big box. It's up to you to decide what's more important.