The coffee bean grinder is of fundamental importance to the coffee
and espresso brewing process.
A typical commercial coffee bean grinder consists of 5 main
parts each of which we will now explore in more detail.
Bean Hopper – The sits on top of the main body
of the unit and obviously contains the roasted coffee beans that by
means of gravity feed beans directly to the grindstones. Commercial
grinders typically have a hopper that can hold 1 full kilogram of
coffee beans. Most grinders these days have an automatic cut off
feature that cuts the power to the grinder if the hopper lid has
been removed.
For general maintenance purposes the hopper should be removed,
washed with warm soapy water, rinsed and dried on a weekly
basis.
Motor – The grinder motor on commercial
grinders are large robust electric motors usually operated by a
start/stop switch on the base of the casing. The motor should be
designed so that it avoids the grindstones overheating and
scorching the coffee.
Grounds Reservoir and Doser – Good quality
grinders usually contain a sensor in the reservoir that senses when
the coffee grounds are running low and automatically tops up the
reservoir. At the base of the unit a segmented wheel or lever
device allows the user to dose the correct amount of ground coffee
into the filter handle of a typical espresso machine. This is
usually set up to be between 6 to 8 grams for each dose. Beneath
the doser is a cradle to hold the filter handle in the correct
position beneath the dispensing hatch.
The doser should be completely emptied, cleaned with soapy
water, rinsed and dried on a regular basis.
Grindstones – Located between the base of the
hopper and the top of the motor are the grindstones. The top stone
fits to a finely graduated screw type adjuster, set within the
casing. The bottom stone is fixed to the motor drive. The screw
adjuster alters the distance between the two stones and
consequently the degree of grind of the coffee. Only a very small
adjustment is needed to dramatically alter the degree of grind.
Tamper –Tampers range from grinder to grinder,
but are usually fixed stubs or plungers on the body of the doser.
Some professional baristas prefer to use stand alone tampers made
of wood or aluminium. The purpose of the tamper is to assist the
operator in compacting the coffee in the filter handle so it
produces a compacted wad of coffee for use in the espresso
machine.
General maintenance procedures dictate that the grindstones are
dismantled and thoroughly cleaned of all coffee residues, using a
long stiff brush and a clean cloth.
Grindstones have a limited life and will need replacing after
approximately 300-500 kilograms of coffee beans have been used.
Written by Fenton Wayne - (Fenton Wayne is an independent advisor
in the coffee and vending trade where he has over 25 years
experience. This article has been submitted to and distributed
by www.submityourarticle.com)