Grinding Coffee
The most convenient coffee to buy is already ground. After all, it's available everywhere and easy to load into the coffee maker. However, ground coffee expires at a faster rate than whole bean coffee, and the fresher your coffee, the more flavor in your cup when it's brewed. Grinding coffee right before its brewed is important to ensuring a fresher cup of coffee every time.
There are two main types of coffee grinders, each with pros and cons, and a full range of ground coffee from fine grind to coarse grind.
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Two Coffee Bean Grinders
There are two main kinds of coffee bean grinders made for home use: the "coffee mill" sometimes called the burr grinder, and the more common propeller grinder.
Burr Grinder
The burr grinder grinds the beans using two burrs, or serrated discs. You set the type of grind you want, load the beans into the chamber, and start grinding. Ground coffee collects in a second chamber ready to be brewed.
Compared to the propeller grinder, it will take a little longer to grind beans with a burr grinder. In my personal experience, I assumed the first time I used a burr grinder that it was defective because it was taking so long. That can be the downside, although I now own the Cuisinart burr grinder, and it grinds as quickly as my old propeller grinder did. The major upside is that a burr grinder produces a consistent grind. If you put ground coffee from a burr grinder under the microscope, you would see a consistent grind throughout. Consistency is very important to the process of making good coffee. This makes a burr grinder a valuable kitchen appliance to have.
Propeller Grinder
The more common grinder is the propeller grinder, known for its two-sided single blade that spins and chops the beans at the same time. After loading the beans into the chamber and grinding, you decide when to stop grinding the beans based on personal experience and through the transparent cover of the grinder.
Unlike the burr grinder, there is no second chamber into which consistently-ground coffee collects. Instead, you decide when to stop grinding. Of course, you can open the lid to take a closer look at the coarseness of your ground coffee and continue grinding if need be. Some propeller grinders still with life in them need to be thrown out. The heat of the propeller will affect the flavor of the coffee, and not in a good way.
What you get the propeller grinder gives you an inconsistent grind and potentially burns your coffee. Why use it? First of all, it's the more common coffee grinder so you'll find it at a lower price and after all, it still does the job, just not as consistently as the burr grinder. But, the burr grinder takes time to grind, and the propeller grinder does the job in a fraction of the time, which is another reason.
Type of Coffee Grind
Another popular question is how finely to grind coffee? How coarse or fine your grind depends on your brewing method, and that's the topic of our next discussion. For now, what you need to know is that:
Different brewing methods take different amounts of time to combine water and coffee into one hot brewed beverage.
The longer the heated water is going to be exposed to the coffee, the coarser a grind you will use.
In the drip brewer common to North American households, you would use a medium grind.
Using a Fine Grind
With espresso, the steam of water is forced through the ground coffee. This means the water is exposed to the coffee for a much shorter time and therefore, a fine grind is used. As mentioned at the outset, your source for whole beans will have an industrial grinding machine where you choose the setting and grind onsite. In a specialty coffee shop, you can trust this machine. Otherwise at a grocery store or outlet of a smaller coffee chain, assume the machine will not give an accurate grinding. These machines require maintenance and calibration on a regular basis, and it's up to you to trust in whether that is happening often enough or at all, particularly with grocery stores.
Using a Medium Grind
Remember to grind what you need right before brewing. Use a burr grinder preferably. Finally, grind to a coarseness that suits your brewing method. In the case of conventional North American drip brewing, go with a medium grind.