Roasted coffee beans must be ground to break the whole beans into smaller pieces to increase the surface area for better coffee extraction. Smaller coffee particles give away the flavor much quicker. Depending on your equipment and brewing method, the right ground particle size must be chosen for ideal coffee extraction. Due to oxidation that will start to affect the coffee grounds right after the beans are ground, it is always a good idea to grind the coffee beans just before brewing and with the right amount. Let’s find out the difference between the two coffee grinder types, burr and blade grinders.
The blade grinder is the cheapest and the most straight forward coffee grinder commonly found in most stores. Equipped with a motor and a blade, the user just has to throw in the beans, cover the grinder and press the power button. The grinding blade will rotate, whack through the beans and break them into small pieces.
The grind size depends on the duration of the grind, that is, a finer grind is achieved by turning the grinder on for a longer time. It looks simple but you have no control over consistency and grind size. Regardless of the duration of the process, the blades brake coffee beans randomly and your ground will contain the particles ranging from powder to chunks. The difference is just the proportion of these sizes.
The burr grinders may be split into two types: flat blade and conical. The conical burr grinder has 2 cone-shaped burrs facing each other at an adjustable distance that determine the grind size. Coffee beans are fed between them and crushed into uniform grind particles when one of the burrs rotates while the other is stationary.
The flat blade grinder also comes with 2 flat and parallel blade burrs that provide a shearing effect on the coffee beans, thus achieving uniform and larger surface area for better coffee extraction.
So, the burr grinder will produce better ground quality and as a result the better final cup taste. Even if you choose a quality automatic coffee maker with a built-in burr grinder instead of purchasing a dedicated full-featured burr grinder, this combo will provide a better result.
Burr grinders can be further categorized based on the rotation speed, dosing capability and the type of grind adjustment available. In terms of speed, there are high-speed direct drive, low speed with gear-reduction, and low-speed direct-drive grinders. The entry-level burr grinders are the high-speed direct-drive grinders. The high-speed motor is connected directly to the burrs. High-speed grinding produces more heat that affects the quality of the end grounds, noise that is not so pleasing to the ears, and the static that will lump the grounds into chunks that can negatively affect the packing of the coffee cake in the portafilter when making espresso. Although, even with these disadvantages, these grinders will still do their job in producing good uniform grinds at a low price point.
The low-speed with gear-reduction or low-speed direct-drive grinders are the best grinders that have no problems described above. They are commonly used in commercial setups as well as at homes of coffee enthusiasts. They offer little or no static at all, much lesser or no unwanted heat and operate quieter.
The low-speed grinder with gear-reduction has a high-speed motor connected to the burrs via a set of gears to reduce the speed and maintain the grinding power. The weakness, as expected, is the noisier grind as compared to the direct-drive low-speed grinders. So, if your wallet permits, go for the direct-drive low-speed grinders such as the Baratza Sette 270 or the Baratza Virtuoso.
The next criteria while choosing the burr grinder is the selection between “doser” and “doserless” grinder. Dosers are designed to grind the beans in batches into a doser container that usually can hold up to around 6 dosages of grounds. A pull on the handle provided will dispense an individual dose of grounds. But most of the home setups are used to make one or two cups at a time. In this case, using the doser grinder you will get some unused grounds and some extra parts to clean after the grinder usage. On the other hand, the doser burr grinder resolves the static problem but that’s not a big deal if you love a fresh ground in each cup. The static problem can be efficiently solved if you go with a direct-drive low-speed grinder. I strongly recommend the doserless grinder for home setups.
Finally, about the types of grind size adjustment, there are the stepped and the stepless grinders. Stepped means some discreet presets like 1,2,3… While stepless adjustment allows more control. This is the most subjective and individual part.
Top-notch stepped grinders provide dozens of steps, which in most cases are pretty sufficient to satisfy even the pickiest coffee lovers in terms of grind controls. More slightest adjustment of the grind size offered by stepless grinders may prove to be too exhaustive.
So my verdict is to go for a doserless, direct-drive low-speed burr grinder. As explained earlier, having a good grinder is the key to consistent and quality brew for every cup.