Last modification of the page done on 03 25 2018 17:51

logo aicmc

International association of collectors
of coffee grinders

drapeau français Change for french websitedrapeau français

Coffee grinding systems

Percussion grinding

mortier 1 mortier 2

To perform a grinding by percussion, two elements are required: a fixed element in the shape of a bowl, called mortar and a mobile element called pestle.
Pestle and mortar are generally made of very hard materials such as stone or bronze (Maghreb mortar).
Grinding gestures are roughly circular movements and occasionally vertical, combining percussion and percussion posed.

Mortar and pestle have been used since ancient times by apothecaries and pharmacy preparers to pound various products of the pharmacopoeia for pharmaceutical preparations.
They are one of the most common symbols of preparers around the world.
They were and still are used in traditional societies to grind grain in the absence of mill.
The action performed when using these utensils is called trituration.

Stone grinding

meule de pierre 1 meule de pierre 2

Known in the Maghreb and the Middle East, this small circular stone mill, for domestic use was widely used for grinding seeds, including coffee beans.
Its shape and its material vary according to the geology of the place and its size varies according to the type of seed, the one that grinds the coffee is smaller.

The use of the stone wheel is inseparable from human history, its use remained constant until the end of the nineteenth century,
This mill consists of two grindstones placed one on the other.
The so-called bottom, round, grinding wheel presents a central cavity which retains a pivot made of wood or iron, a channel, dug around the millstone, receives the ground, which is scattered on a carpet.
The so-called upper common grinding wheel is less wide, of conical shape it is crossed by a hole which serves for the passage of grain, another oblique hole which allows the establishment of a handle, generally made of wood and therefore the set in circular motion on the grinding wheel.
The grip of the handle is done sometimes with the right hand, sometimes with the left hand, while the right alone pours the grain.
Thanks to the pivot and the rotation, the seed arrives between the two wheels where it is crushed.
The mill rests on a mat, a sheepskin or goat skin that prevents it from moving, so wedged, it is between the legs of the woman who holds them sometimes lying, sometimes one leg bent the other lying down.
The grind is sieved once or twice depending on the desired degree of fineness.
We find this same mill made of terracotta, as a toy for girls.

Grinding by dormant grindstone ormetates

metate 1 metate 2

The metate is a dormant stone wheel, used for home use, which was used to grind corn.
Used for several thousand years (about 3000 BC), especially in Mexico.
In this grinding system, the so-called grinding wheel is the part that remains stationary during the grinding operation and that is in the lower position.

The upper part, called wheel or mano, generally greater than the width of the grinding wheel, seized with both hands and actuated in a reciprocating rectilinear motion.
Roasted coffee, corn or roasted beans, salt, sugar loaves and cocoa are thus reduced to powder.
As for grinding wheels, the use of metate was exclusively feminine.

The Olynthe grinder

The mill of Olynthe (named after the city of Olynthe in Greece which was destroyed in - 348 BC),represents a real technical change.
This type of mill certainly appears from the beginning of the fifth century BC and its use seems common in the Greek world.

broyeur d’Olynthe 1

In the olynthian mill, the lower grinding wheel (4) is of rectangular type, placed on a table (5) The grinder, which constitutes the upper grinding wheel (3), is usually rectangular in shape, sometimes oval, and has in its center a parallel hopper with long sides and intended to receive the grain to grind.

This mill is surmounted by a horizontal axis (2) fixed on one side on the table to a pivot (1), the other end being actuated in a movement back and forth horizontal of the lever (2).

broyeur d’Olynthe 2

The Olynthe mill has a start of mechanization, the user is now standing and the work is facilitated.
The demand for this mill was so great that it was standardized and there were 22 hopper mills in the cargo of a wrecked ship off Kyrénia, dated to the end of the 4th century BC.
The use of this type of mill was not limited to the milling of the grain, but also for the calibration of the ore.
Agatharides' text on the gold mines of Egypt in the 1st century BC, transmitted by Photius and Diodorus, evokes a mill with a lever:
"Older women and men then receive this crushed pea-sized ore, throw it into the millstones, in large numbers, two or three people standing at each lever and molding it."

The mechanical grinder

This is the traditional hand-coffee grinder.

mecanisme de broyage  2

The coffee mill has a grinding chamber, comprising two grinding members.
There is always a fixed part and a rotated part, this moving part is driven by a crank in direct drive (table or wall-mounted mill) or indirect (counter mill).
The rotated part is provided with sharp grooves, the fixed part is grooved.
The grain is introduced into a hopper, which brings it into the grinding chamber, when the crank is operated, the rotated part crushes the grains against the fixed part.
The size of the grind can be adjusted by clamping the two grinding elements more or less against each other.
The main advantage of the mechanical grinding mill is the ability to obtain a very uniform grind and a slower milling process that does not heat the grains.

broyeur  1

First made for grinding spices, they will be quickly adopted to grind coffee, after some improvements (adapted grinders, adding a drawer, etc. ..)
These very first coffee grinders appear in Turkey (XVI century), then we find them, from the XVII century, in France.

Electric blades coffee grinder

Certainly the best grinding system, for the coffee bean.

broyeur electrique 1

Price sometimes high, but as with the manual mechanical mill, the grains are crushed between grinding wheels. The conical wheels grind the grains with precise uniformity while preserving the full aroma of the coffee.

Example of 3 patents concerning coffee grinders

Example No. 1:

brevet thomas bruff

The first coffee-grinder patent in the United States was issued to Thomas Bruff, Sr., in 1798.

Example No. 2:

brevet W.B.Thompson

"... This invention relates to certain new and useful improvements in coffee mills of that class wich are designed to be affixed in any desired position upon a wall or other support, and it has for its object among others to provide a simple, cheap, yet convenient mill, which has for use in connection therewith a pivoted receptacle for catching the ground coffee as it comes from the mill, the said receptacle being graduated and supported upon a pivoted part so mounted as to throw the preponderance of weight toward the support so as to prevent accidental tipping of the receptacle to the front, ..."

Example No. 3:

Bunn-O-Matic Corp.

brevet Bunn-O-Matic Corp

An electric motor driven coffee grinder is turned on by manually activating an on/off/start switch when a bag is in position to receive ground coffee under a discharge chute and automatically turned off when the bag is removed.
The grinder motor is controlled by both the manual on/off/start switch and by a switch which is actuated by a pivotally mounted lever responsive to the presence and absence of a bag under the discharge chute.
This lever is designed to assume a switch-off position when no bag is present and is pivoted to a switch-on position when a bag is present.

Legal notice

F. A. Q.

Website created by AICMC members - © AICMC 2012 - All rights reserved
Reproduction is prohibited without the written permission of AICMC
The association is absolutely not involved in commercial transactions between collectors.
The association is only interested in the heritage value of objects.
Note : we do not offer a valuation service
Use the Contact Us page to send us the request form with questions you may have