Burr Coffee Grinders
A burr coffee grinder is key to making a great cup of coffee.
A grinder is often overlooked as a key part in making a great cup of coffee. You should always grind whole coffee beans yourself, right before you brew the coffee. Grinding releases oils and chemicals trapped in the beans which break down quickly to light, heat, and air. It's those elements that grinding releases that makes a great cup of coffee.
Burr coffee grinders are better than blade grinders
A blade grinder has a sharp metal blade that spins at a very high and consistent rate of speed. It pulverizes the coffee bean repeatedly until the desired consistency is reached. The major disadvantage of the blade grinder is the lack of uniformity of the coffee grinds it produces. The rapidly spinning blade constantly pulverizes coffee beans, creating fragments and powder of differ net sizes.
The uneven grind produced by these machines will lead to inconsistent brewing and uneven extraction of flavor from the coffee grounds. If you continue to grind to produce finer grinds, you can burn the coffee grounds because of high heat produced by the motor and high speed blade. The excess heat damages the beans' aromas and oils.
Professional roasters use burr coffee grinders
The burr coffee grinder is the recommended way for grinding coffee, ideal for almost any brewing application. A burr coffee grinder strips off slivers from the coffee bean, exposing the cellular wall structure and providing a lot of surface area for the water to extract all that coffee goodness from. Burr coffee grinders also produce a lot less heat in the bean when compared to a blade grinder, which further helps promote the maintenance and durability of the aromatics and oils that promote great tasting coffee.
Doser and Doserless coffee grinders
Burr coffee grinders can be purchased in doser and doserless models. A "doser" grinder is a machine that has a compartment in the front with a set of rotating vanes. You move these vanes by flicking a lever, and each flick doses out a portion of ground coffee into a portafilter of an espresso machine (the device that holds the espresso filter). Doserless coffee grinders feature a direct chute by which coffee is dispensed directly into a collection container. The chute design makes it practical to grind directly into a storage container for later use.
The Rancilio burr grinder is a doser grinder and the Saeco burr grinders are doserless grinder.
Adjustable for different size grinds
All burr coffee grinders have a way of adjusting the fineness or the size of the coffee grounds for different coffee makers and espresso machines. By either turning an adjustment wheel or the bean hopper on a burr grinder, you are actually adjusting the distance between the two metal parts that make up the cutting surfaces of your grinder. Different coffee brewing methods require different size grinds.
Coarse Grind: As the name implies, the resulting grinds are comparatively large, with each chunk of bean particle having the approximate size of a particle of common sand, or larger. This grind is suitable for percolators, French press coffee makers, pour through makers, and drip coffee makers.
Medium Grind: Often known as the "general purpose grind" that is also used as the grinding level for most grocery store pre-ground coffee. The size of the granules resembles the consistency of table salt. A medium grind is very suitable for most auto and manual drip coffee makers and vacuum brewed coffee makers.
Fine Grind: The starting point for an espresso grind, where the granular particles are closer to the size of fine pepper than to salt. When coffee is ground this fine, several factors come into play. You've exposed more overall surface area per mg that the brewing water can contact - excellent for a nice full extraction in espresso. But by grinding this fine, you've increased the resistance the grind gives to the passage of water - this means that a fine grind may clog up a paper filter in an auto drip coffee maker, but the 9 BAR (or greater) pressure of an espresso machine has enough power (some 135 psi worth) to push through those grounds and deliver you a rich, full beverage.