The “key” that decides how we unlock the secret tastes in the coffee beans is the grinder. However, if you aren’t concerned about whether the coffee powder will heat up or not, buying a hero is a straightforward process. Is the fineness the same across the board? How to adjust the class and serve it quickly while keeping the freshness of freshly ground coffee… A balance of the aforementioned is vital for individuals who bring perfectionism to a cup of great Espresso. Quite perplexing, and you won’t be able to put your desired coffee through any grinder unless you fully comprehend them – which is why you’ve come to this page.
However, it would help if you looked at the Coffee Grinding Process, from a scientific perspective, before embarking on research into the tools for grinding coffee.
Main issues when selecting a coffee grinder
Starting with the field of “coffee powder,” you will find two main lines of grinders on the market, which are the blade grinders (Blade Grinders) and the gear grinders (Burr Grinders); you will also quickly realize that blade grinders were narrowing their options and becoming irrelevant in the modern coffee industry’s wave of quality. We focus most of our attention on the line of gear grinders, with the main elements summarized below:
- Quality of ground coffee: depends on the size and shape of the gear (conical gear/flat gear); Engine power
- Blending consistency: depends on the fineness adjustment mechanism, including Stepless Adjustment (infinite fine adjustment) and Step Adjustment (level adjustment).
- Segmentation by the purpose of use: The machine has a compartment for powdered coffee after grinding (Doser), Or the Doserless series – grind and measure each batch separately.
- Other factors include the amount of coffee residue (grind retention), noise level, cost, gear construction material…
Problems related to gear grinders – Burr Grinders
Unlike blade grinders, gear grinders bring you closer to higher-quality coffee. There’s a lot to think about with this grinder, from the form to the gear size and operation. Any problem with any defect in some way with the gear grinder may be solved for a higher amount, including adjustment, grinding dosage… and any problem with any defect in some way with the gear grinder can be solved for a higher amount. Of course, third-wave coffee shops and die-hard espresso fans will accept this. But what factors decide the quality of gear grinders that cost ten times as much?
The quality of your coffee will be determined by the following three variables of a cake grinder:
The first; Gear Size – Burr Size
The first characteristic that distinguishes coffee grinders is their gear size*. In this case, the usual rule of thumb is that the greater the gear, the better. The greater the contact area for grinding coffee beans, the larger the gear size. The wider the gear diameter, similar to a wheel, the more coffee is tilted within the same revolution. To put it another way, your beans will pass through the grinder fast and with minimal heat.
(*) Most blenders usually use gears 40, 50, 54, 60, and the largest is 68mm
Monday; Gear shapes – Conical burr and Flat burr
You only need to see the following figure to visualize the conical gear – Conical burrs and the flat gear (disc) – Flat burr:
A gear shape usually goes hand in hand with its size; With the same diameter, a cone gear has a larger contact area than a flat gear. In addition, conical burrs can operate at a slower rotational speed, as they do not rely on centrifugal force to disperse the beans over the entire plate area (like flat burrs) – gravity will solve the problem. this. However, this does not mean that Conical burrs are better because gravity affects them, so the uniformity is worse than Flat burrs. In other words, grinders that use flat gears tend to grind coffee more evenly, opening the door to a more consistent extraction when brewing.
Espresso and the problem with coffee crumbs – Grind Retention
Another problem, not the pretty third but gear-related and not very important!
If you’ve read through several articles on the topic of grinder selection, you may have come across the term “grind retention” to refer to the coffee crumbs left in the grinder. This is a fascinating topic and relatively trivial (like the analysis of conical burr & flat burr). However, combine a bit of engineering, physics, and economics. You’ll find these leftovers affect all coffee grinders, and when it comes to Espresso, it can be the difference between a perfect espresso and… okay.
With grinders with small gears (40mm) like the Baratza Sette 270, the coffee backlog is almost zero. Whereas with flat bags (60mm and 64mm) on the Eurika Atom and Profitec T64, this is also between 2 – 4.5g, so you – (again) may not care about this issue.
However, in another case, the Eurika Zenith movement (using 65mm conical gears) can leave 12g of coffee per grind. So, if you don’t clean the machine carefully, you’ll end up with 12/20g of stale coffee in the portafilter with inconsistent fineness, or worse, different types from freshly ground beans. Third-wave cafes won’t like this.
Tuesday; Engine, heat, and noise
The engine first, with the same gear structure, which blender has a more potent motor, usually driving the grinding disc with less rpm – aka smaller RPM*, (like when you drive a car). machine with 1, very strong – but slow) so the coffee will be crushed with less heat generated by friction.
Secondly, the engine indirectly leads to noise when operating the machine. Typically, Conical burr grinders run slower than flat burrs, so the noise generated when working is also significantly lower. Since flat gears require high RPM, ensure that the centrifugal force is large enough to spread the coffee over the entire gear area.
(*) RPM = Revolutions Per Minute / Revolutions Per Minute
In summary, we will have:
Powerful engine » low rpm » low friction and heat » low noise » Of course, the cost is high.
Bean size and consistency of coffee grinder
Simply put, it’s the blender’s job to help us get the most out of the flavor and coffee, with the finesse needed for each brewing method while maintaining the best possible uniformity. Body. Therefore, based on the ability to control the fineness of coffee when grinding, we have two main models – Stepless Adjustment (infinite adjustment) and Step Adjustment (hierarchical adjustment).
With conventional grinders first, the fineness of the coffee is pre-programmed by the manufacturer with several different modes, allowing you to switch between the required particle sizes easily. You will quickly grind coffee for Espresso, Pour Over, or French press …; this is called a step adjustment machine.
Stepless Adjustment Series
However, for Espresso, the technical requirements when grinding coffee are much more stringent. The more uniform the particle size, the higher the extraction efficiency, so the Stepless Adjustment blender was born, allowing us to adjust the fineness according to the mechanical mechanism (increasing or decreasing the distance between gears) with higher accuracy. Still, with this mechanism, you will spend more money and time determining the required grind size. Some popular infinite adjustment machines such as M7D Conical Doserless, Eureka Mignon Specialita, Profitec T6
Finally, if you are a barista expecting to make the ideal coffee extraction, switching back and forth between different brewing techniques is still accessible. It’s not entirely impossible, as the Baratza Sette 270Wi combines ten coarse (macro) levels and 27 differential (micro) levels – so you have 270 grind sizes. If you are still unsatisfied, you can choose the Dalla Corte Max, which allows the differential to be adjusted to 0.01mm.
Doser – Quantitative or non-quantitative
After all, almost all problems related to the quality of coffee after grinding have been exposed. Applying to actual use is the last factor we should consider when buying a coffee grinder. In this regard, we have two options: whether or not there is a coffee compartment after grinding – aka Doser.
Machines with a compartment (Doser), with a built-in coffee hopper (like the clip below), the coffee after grinding will be kept in the hopper until you take it to the portafilter and take it out for extraction. The Doser machine series is top-rated in restaurants and cafes because it is suitable for many customers, with the need for continuous preparation. But in return, the coffee will lack the necessary “freshness” in each brew, and you will need to clean the grinder periodically to get rid of the old coffee.
However, if you have a Specialty Coffee shop and need to grind two or three types of coffee a day, this is where you need a grinder with a digital dosing system – Doserless, with a timed dosing mechanism. or gliding mass). You need to insert the portafilter and press the button; the machine will automatically grind the excellent coffee, ensuring freshness. One of these is the Baratza Sette 270 or the Baratza Forté-BG with three grinding modes by weight (15, 30 & 60g).
Some other issues when choosing to buy a coffee grinder
If you find blenders too noisy when used in the kitchen or quiet coffee shops, you will want to find a “noise-canceling” machine. In this regard, blenders with conical gears are generally slower than flat packs. But some manufacturers like Eureka have deliberately integrated the soundproof cover with the Mignon Specialita or Mignon Silenzio series.
Some people may be willing to put in the work for the perfect cup of coffee – and clean up when needed. But others want to be as simple as possible—the more complex the coffee grinders, the more challenging to clean. Typically, stepless adjustment machines with flat gears doser combinations take a long time to clean. You have to reset the grind size afterward – it is best to consult the manufacturer for this item.
Finally, in terms of cost, as with all investments, higher-priced coffee grinders will often be made of better materials designed to last longer. This can save you money when you have to change your blender many times. Moreover, with Espresso, you should spend the maximum on the grinder because no matter how good an Espresso machine is, it cannot improve the quality of coffee from a poor hero.
Can the blade grinder grind coffee?
Why don’t we mention the blade grinder from before? Because when it comes to blade grinders, we seem to be referring to the Excella coffee variety in the model of specialty coffee varieties.
Blade grinders can be pretty handy, affordable, and compact, but most don’t perform well for coffee. The main disadvantage of this line of blenders is that they lack accuracy. Since you have to estimate the grinding time, the blade design creates uneven sizes when grinding, and with the high rpm, the heat generated is high, so the coffee is easy to release flavors or, worse, burn—burnt before brewing. However, not all blade grinders are harmful, such as the Krups Fast Touch and Epica Electric Coffee that can be used at home.
Finally, the blade blender should be in its proper place – grind vegetables, make juice instead of coffee