Conical burr coffee grinders - What's that? Do I need one? Where can I get one?

Although acquiring your very own roasting machine or espresso machine may be a little too ambitious for most of us, you may decide that bringing your coffee at least one stage closer to perfection by grinding the beans yourself is probably a good idea.

Coffee Grinders are an absolute must have for any coffee lover. Grinding your coffee just before you use it allows you to taste it with its complete aromatic profile. The best coffee you've ever tasted is maybe just one step away.

Coffee beans, like any other food product, will oxidize when exposed to air after a given period of time. The coffee grounds, having a much greater relative surface area than the bean, and no outer protection, suffer this effect even more so. Therefore, the ultimate coffee experience comes from grinding the beans just before brewing: it produces the least amount of exposure to air, and therefore produces the freshest grounds.  

Different sized coffee grounds are required by different coffee makers. An espresso machine requires the finest ground coffee. Drip / filter machines require medium grounds and, due to its relatively large-holed filter, a French press (Bodum) requires very coarse grounds. At the time of brewing, the finely ground coffee has more surface area in contact with the water. That means that by using finely ground coffee, you will be able to extract the same full flavor that you would normally get from a large portion of coarsely ground coffee.

But over extraction occurs when grounds come into contact with too much water. French press requires a coarse grind because the coffee steeps for up to 4 minutes. An espresso machine requires a fine grind because the equipment is designed to force a small amount of pressurized water through the grounds for less than 25 seconds.

A good grinder will produce grounds of a consistent and accurate size without too much friction. If you choose to invest in a coffee grinder, pick the best you can afford. 

Coffee grinders fall into three broad categories - Crusher, Blade and Burr.

This is some kind of a mashing device, often an ancient-style mortar and pestle, that crushes the coffee beans. It is usually hard to use, and it produces very uneven sized granules, that produces uneven flavor extraction as the water filters through the grinds.

Not really recommended.

The blade grinders don't actually grind at all, they chop the coffee beans. A whirling blade slices the beans into smaller and smaller chunks, until they approach a size similar to that of a small grain of sand or salt. Unfortunately, the coffee grains will normally be of uneven sizes.  As a consequence the surface areas of the granules vary, releasing varying amounts of flavour oils when brewed.

Another effect of slicing is the production of excess heat as a result of the high speed of the blades (20 to 30,000 rpm is typical). The heat is the nemesis to the flavor and aroma of roasted coffee beans. It accelerates the chemical reactions that lead to a loss of coffee flavornoids, partially dissipating the flavor and aroma. And the friction is prone to burn the coffee grounds, giving the coffee an undesirable taste, such as being more bitter or with a burnt flavor.

Only buy a blade grinder if :

•  you will not be making espresso.
  
•  you are not prepared to spend more money on a burr grinder and you're in the "blade or nothing" case. Any fresh grind is better than buying pre-ground. 
  

These grinders work by crushing the beans between two discs or wheels, one spinning and the other being stationary. The burrs still spin very fast (10 to 20,000 rpm), generating heat, but create a thorough and consistent grind, well-suited for use in an espresso machine. 

The conical burr grinder is preferred by real coffee aficionados. Good conical burr grinders can rotate their plates as slowly as 500rpm. This obviously allows very little heat to no heat passed through to the coffee grounds. And the shape (like a cone head) dissipates the heat rather well.

Most also have up to 16 precision settings, from very coarse for French press brewing to extra fine for espresso or Turkish coffee. Because of the wide range of grind settings these grinders are ideal for all kinds of coffee equipment : Espresso, Drip, Percolators, French Press.

Thus the conical burr grinder is the ideal type of coffee grinder for those that love the flavor in their gourmet coffee. It is for those who have finally realized what a sensuous, ravishing, and complete experience a perfect cup of coffee is, and who would like to duplicate that experience at will in the comfort of their own home.