Coffee grinders are an indispensable tool in every coffee lover's home because of the important procedure of grinding coffee beans into coffee powder to get the perfect cup of coffee.
Historical records that in 800 AD, Ethiopians discovered coffee in abundance and fell in love with the beverage, they then chose something in the shape of a stone or wooden style, and even in some places used a mortar and pestle to crush the coffee beans.
By the time coffee machines were first introduced to the Greeks around 1350 B.C., they came up with the idea of the coffee grinder, a machine used to crush coffee beans into a fine powder. As technology progressed, many impressive and advanced coffee grinders emerged.
Today let's get to know the burr coffee grinder.
What is a Burr Grinder?
A burr grinder is a grinder for grinding hard small food products between two rotating grinding surfaces, the distance between which is usually set by the user. When the two surfaces are farther apart, the resulting ground material is coarser, and when the two surfaces are closer together, the resulting ground material is finer and smaller. Typically, the device includes a rotating screw that pushes the food through.
Bean grinders are generally divided into manual grinders and electric grinders.
Burr grinders do not heat the ground product by friction as blade grinders ("choppers") do and produce uniformly sized particles determined by the separation between the grinding surfaces.
How does a Burr Coffee Grinder Work?
The uniform particle size and variable settings of the burr grinder make it ideal for coffee preparation, as different coffee preparation methods require different sizes of grinds.
Grind size depends on the width between the two burrs, into which the coffee beans fall and are ground several at a time. Finer grinds allow for greater surface area in contact with water, resulting in more complete extraction of caffeine and flavor.
Grinds range from the finer end of Turkish coffee and espresso to the coarse/extra coarse end of French press and cold extraction, as well as the medium-fine to medium range of pour-over and drip coffee.
Burr coffee grinders are also better for keeping the flavor and aroma of the beans intact, as they generate less frictional heat than blade grinders. If the beans become too hot during the grinding process, the oils and aromas can easily dissipate, although most grinders do not heat the beans to a high enough temperature to risk this happening.
Types of Burr Grinders
When it comes to bean grinders, the core of it is the cutter plate. The cutter plate classification is also very much, the material is mainly ceramic and metal.
Features of ceramic material：
- Generates less heat
- No rust can be washed
- The material is fragile
Features of metal material:
- The material contains cast iron and alloy, a sharp blade
- Easily rusted
- The heat generated during grinding is higher than ceramic, but if only a small amount of coffee beans are ground, the heat is negligible
If we look at the cutter discs, there are three main types: flat burr grinder, conical burr grinder, and ghost teeth burr grinder, let's see their advantages and disadvantages respectively.
1) Flat Burr Grinder
- Its grind disc is placed in a parallel way, when grinding coffee beans, relying on the force of the bottom disc rotation, the coffee beans will be pushed into the disc. The weight of the coffee beans placed affects the evenness of the coffee entering the cutter disc, which in turn affects the evenness of the grinding.
- Because of the pushing and squeezing, the number of collisions of the coffee beans is increased, so the proportion of fine powder produced is increased. This is the reason why the flat burr grinder grinds slightly fewer uniform particles and more fine powder.
- The ground coffee particles are flaky, allowing the cell wall area to increase, thus enhancing the concentration and extraction rate of the coffee liquid for a short period and the aroma of the coffee for a short period. However, at the same time, because of the flat and long shape and larger volume, the extraction time becomes longer, making the coffee hash and astringency increase.
- It is most suitable for grinding espresso coffee powder.
2) Conical Burr Grinder
- It is placed at the bottom of the conical knife disc, and then grind with the cooperation of the outer ring knife disc, the coffee beans will fall from the top, and with the rotation of the knife disc, the coffee beans will be pulled downward, and then produce grinding action, reducing the number of collisions between particles and the proportion of fine powder produced, and also enhance the uniformity of coffee grinding.
- The coffee it grinds is granular and not easily absorbed, so the initial release of soluble substances will be less, and the concentration of coffee will not be too high for a short period. But at the same time, he will not make the coffee has a stray taste and astringency because of the long extraction time.
- The coffee powder ground by the tapered knife grinder is suitable for use in pour-over coffee, siphon pots, and other appliances.
3) Ghost teeth burr grinder
- It grinds the coffee powder close to round, and the coarseness is also more uniform, so the coffee taste is cleaner and the flavor is rich and full, but the price is higher.
- Its structure is molar-shaped, can grind coffee beans in an oval shape, coarse and fine between the flat and conical knife.
- Because of the special shape of the grinding disc of the ghost teeth, it can only be formed by casting a one-time, there is no way to secondary processing through precision instruments, so the surface is relatively rough, and the precision is not high. This is also the case if the hot processing improves the hardness of the counter to deformation, so the ghost tooth discs are generally not sharp enough that hardness can only reach the level of cast iron.
How to Choose a More suitable Burr Grinder for Yourself?
1. Strong aroma, using a flat burr grinder its aroma will be much more obvious than with a conical burr grinder.
2. When a better taste is needed, the granular coffee powder produced by the cone knife can make the wood contact time with water reduced, although the aroma is not as obvious as the flat knife, even if the extraction time is extended, the taste is still better.
3. The ghost teeth grinder has the best performance options in all aspects and produces a more moderate flavor. In addition to the key factor of uniformity, the ghost tooth grinder is more suitable for testing the flavor of coffee beans.
The bean grinder is among all equipment, that most should spend a lot of money to buy, as long as you have tasted freshly ground coffee, you never want to go back, good maintenance and a bean grinder with 5 years or more is not a problem.