![Poppy seed grinder Jupiter 560](https://upload.wikimedia.org/wikipedia/commons/8/87/Poppy_seed_grinder_Jupiter_560.jpg)
A burr mill, or burr grinder, is a
mill
Mill may refer to:
Science and technology
*
* Mill (grinding)
* Milling (machining)
* Millwork
* Textile mill
* Steel mill, a factory for the manufacture of steel
* List of types of mill
* Mill, the arithmetic unit of the Analytical Engine early ...
used to grind hard, small food products between two revolving abrasive surfaces separated by a distance usually set by the user.
When the two surfaces are set far apart, the resulting ground material is coarser, and when the two surfaces are set closer together, the resulting ground material is finer and smaller.
Often, the device includes a revolving screw that pushes the food through. It may be powered electrically or manually.
Burr mills do not heat the ground product by friction as much as
blade grinder
A blade grinder, also known as propeller grinder, is a machine that chops material while mixing it, by means of a high-speed spinning blade. Applications of blade grinders for preparing foods include numerous electric kitchen appliances such as ...
s ("choppers"), and produce particles of a uniform size determined by the separation between the grinding surfaces.
Food burr mills are usually manufactured for a single purpose:
coffee
Coffee is a drink prepared from roasted coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulant, stimulating effect on humans, primarily due to its caffeine content. It is the most popular hot drink in the world.
S ...
beans, dried
pepper
Pepper or peppers may refer to:
Food and spice
* Piperaceae or the pepper family, a large family of flowering plant
** Black pepper
* ''Capsicum'' or pepper, a genus of flowering plants in the nightshade family Solanaceae
** Bell pepper
** Chili ...
corns, coarse
salt
Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantitie ...
,
spice
A spice is a seed, fruit, root, bark, or other plant substance primarily used for flavoring or coloring food. Spices are distinguished from herbs, which are the leaves, flowers, or stems of plants used for flavoring or as a garnish. Spices a ...
s, or poppy seeds, for example. Coffee mills for volume consumption are usually powered by
electric motor
An electric motor is an Electric machine, electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a Electromagneti ...
s, but fast and precise manual mills have experienced an uptick in popularity in the 2020s for individual-serving
pour-over and
espresso
Espresso (, ) is a coffee-brewing method of Italian origin, in which a small amount of nearly boiling water (about ) is forced under of pressure through finely-ground coffee beans. Espresso can be made with a wide variety of coffee beans and ...
. Domestic pepper, salt, and spice mills, used to sprinkle a little seasoning on food, are usually operated manually, sometimes by a
battery
Battery most often refers to:
* Electric battery, a device that provides electrical power
* Battery (crime), a crime involving unlawful physical contact
Battery may also refer to:
Energy source
*Automotive battery, a device to provide power t ...
-powered motor.
Coffee grinders
![Coffee grinder mechanism](https://upload.wikimedia.org/wikipedia/commons/4/4a/Coffee_grinder_mechanism.jpg)
The uniform particle size and variable settings of a burr grinder make it well-suited for
coffee preparation
Coffee preparation is the process of turning coffee beans into a beverage. While the particular steps vary with the type of coffee and with the raw materials, the process includes four basic steps: raw coffee beans must be roasted, the roasted ...
, as different methods of coffee preparation require different size grinds. The size of the grind is determined by the width between the two burrs, into which the coffee beans fall and are ground a few at a time. A finer grind allows a larger surface area to come into contact with the water, which yields a more complete extraction of caffeine and flavor. The grind spectrum ranges from Turkish coffee and espresso on the finer end to a French press and cold brew extraction on the coarse/extra coarse end, with pour-overs and drip coffee in the medium-fine to medium range.
Burr coffee grinders are also more suited for keeping the flavor and aroma of the coffee beans intact, as they produce less heat from friction compared to blade grinders; "The oils and aromas can easily dissipate if the beans become too hot during grinding, although most grinders will not heat the beans to a high enough temperature to risk this occurring."
Burr grinders obtain these lower speeds and even grind through two mechanisms. The lower cost models generally use a small electric motor to drive a series of reduction gears, while better constructed and more costly examples use a larger commercial motor and a belt, with no gear reduction to spin the burrs. The latter example is termed "direct drive". The reduction gear versions are noisier and usually do not have the lifespan of the direct drive units.
Electrical powered burr grinders are available in many variations. Some grinders are "stepped" meaning that they are fixed by the factory into a set series of adjustments while "stepless" varieties use a
worm drive
A worm drive is a gear arrangement in which a worm (which is a gear in the form of a screw) meshes with a worm wheel (which is similar in appearance to a spur gear). The two elements are also called the worm screw and worm gear. The terminolo ...
or other mechanisms to offer a near-infinite number of adjustments within their grind range. Other variations include grinders that are equipped with dosers and others that are "doserless". Dosers function as a catch bin to collect the ground coffee and by using a lever, users are able to dose a set amount of coffee. Doserless versions remove the bin and dosing function, and the grinder outputs the ground coffee directly into an
espresso machine
An espresso machine brews coffee by forcing pressurized water near boiling point through a "puck" of ground coffee and a filter in order to produce a thick, concentrated coffee called espresso. The first machine for making espresso was built in ...
portafilter
An espresso machine brews coffee by forcing pressurized water near boiling point through a "puck" of ground coffee and a filter in order to produce a thick, concentrated coffee called espresso. The first machine for making espresso was built in ...
or into another container. The doserless examples normally feature additional functions such as weight based or advance time based grinding in order for a barista to grind for an exact amount of grounds required for a specific espresso shot.
Manual coffee grinders have been largely supplanted by electrically powered ones for speed. Manual grinders are used for convenience and aesthetic reasons and are usually less costly than electric models. An example is the manual
Turkish coffee grinder; these are inexpensive and can grind coffee to fine powder for
Turkish coffee
Turkish coffee is a style of coffee prepared in a ''cezve'' using very finely ground coffee beans without filtering.
Preparation
Turkish coffee is very finely ground coffee brewed by boiling. Any coffee bean may be used; arabica varieties are c ...
.
Manual grinders
Manual burr grinders are turned by hand, rotating one grinding surface against the other. Coffee mills usually have a handle, providing leverage for the many turns required to grind enough coffee for a cup. The ground coffee is collected in a container which is part of the mill.
Salt
Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantitie ...
,
pepper
Pepper or peppers may refer to:
Food and spice
* Piperaceae or the pepper family, a large family of flowering plant
** Black pepper
* ''Capsicum'' or pepper, a genus of flowering plants in the nightshade family Solanaceae
** Bell pepper
** Chili ...
, and spice mills, essentially the same as coffee mills, usually do not have a handle, the entire top rotating instead. While this is less convenient, only a few turns are required to grind enough. The ground product falls directly onto the food being seasoned; the mill has no container. A few designs have abrasive surfaces which do not rotate; each squeeze of the handles moves one flat plate past another, then the plates are restored to their original position by a
spring
Spring(s) may refer to:
Common uses
* Spring (season), a season of the year
* Spring (device), a mechanical device that stores energy
* Spring (hydrology), a natural source of water
* Spring (mathematics), a geometric surface in the shape of a ...
. Many hard spices are available in containers incorporating a simple cone burr grinder, intended to be discarded when empty.
Most grinders can be adjusted to set the fineness of grind.
Manual mills can be used for grinding other food products than they are intended for, but mills designed for pepper grinding are inappropriate for producing finely-ground
flour
Flour is a powder made by grinding raw grains, roots, beans, nuts, or seeds. Flours are used to make many different foods. Cereal flour, particularly wheat flour, is the main ingredient of bread, which is a staple food for many culture ...
.
Laura Ingalls Wilder
Laura Elizabeth Ingalls Wilder (February 7, 1867 – February 10, 1957) was an American writer, mostly known for the ''Little House on the Prairie'' series of children's books, published between 1932 and 1943, which were based on her childhood ...
's novel ''
The Long Winter'' describes a family grinding
wheat
Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeologi ...
in a coffee mill to make flour during months of hardship.
The first coffee grinder was made by Richard Dearmann, an English
blacksmith
A blacksmith is a metalsmith who creates objects primarily from wrought iron or steel, but sometimes from #Other metals, other metals, by forging the metal, using tools to hammer, bend, and cut (cf. tinsmith). Blacksmiths produce objects such ...
from
Birmingham
Birmingham ( ) is a city and metropolitan borough in the metropolitan county of West Midlands in England. It is the second-largest city in the United Kingdom with a population of 1.145 million in the city proper, 2.92 million in the West ...
, in 1799. This grinder was widely distributed in the US, where Increase Wilson patented the first wall coffee grinder in 1818.
Peugeot of
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
patented a pepper grinder in 1842. The mechanism of
case-hardened steel cracked the peppercorns before the actual grinding process. The grooves on the Peugeot mechanism were individually cut into the metal and then case-hardened, making them very durable.
Image:Peppermill.jpg, A pepper mill
Image:Saltmill.jpg, A salt mill
File:Disposable salt mill, computed tomogram (4).jpg, Grinding gear from a disposable salt mill, computed tomography image
File:Peppergrinder 3D-flight-through microCT.OGG, Flight through a 3D reconstruction of a disposable pepper grinder, from CT-data
File:Woodturning-15-Peppermills-gje.jpg, Wooden manual pepper mills from Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
Types of burr mill
Materials
There are several types of materials used in pepper mills, each with its own particular advantages.
Corrosion-resistant
Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engine ...
materials are used to grind salt.
Stainless steel
Stainless steel is an alloy of iron that is resistant to rusting and corrosion. It contains at least 11% chromium and may contain elements such as carbon, other nonmetals and metals to obtain other desired properties. Stainless steel's corros ...
: One of the most suitable and durable materials for grinding peppercorns and coffee beans. The male and female sections of the grinding mechanism are usually made from
sintered
Clinker nodules produced by sintering
Sintering or frittage is the process of compacting and forming a solid mass of material by pressure or heat without melting it to the point of liquefaction.
Sintering happens as part of a manufacturing ...
metal. This material is preferred by professional chefs. The teeth of the grinder are machined to cut spice or beans. Stainless steel is not suggested for grinding salt.
Zinc alloy
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic ta ...
: Perhaps the most common mechanism found in pepper grinders, zinc alloy is composed of a mixture of metals, primarily zinc, often with
chrome plating
Chrome plating (less commonly chromium plating) is a technique of electroplating a thin layer of chromium onto a metal object. A chrome-plated item is called ''chrome''. The chromed layer can be decorative, provide corrosion resistance, ease ...
to resist corrosion. It is a good choice for grinding pepper but is not suitable for grinding salt.
Carbon steel
Carbon steel is a steel with carbon content from about 0.05 up to 2.1 percent by weight. The definition of carbon steel from the American Iron and Steel Institute (AISI) states:
* no minimum content is specified or required for chromium, cobalt ...
: An extremely hard metal, carbon steel provides the sharpest edges and most efficient grinding capability, and is preferred by professional chefs.
Carbon steel is not suitable for grinding salt.
Ceramic
A ceramic is any of the various hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcelain ...
: Ceramic is extremely hard and provides the best performance for multi-use grinding. It does not corrode and is suitable for grinding coffee beans,
pepper, salt, and spices.
Acrylic
Acrylic may refer to:
Chemicals and materials
* Acrylic acid, the simplest acrylic compound
* Acrylate polymer, a group of polymers (plastics) noted for transparency and elasticity
* Acrylic resin, a group of related thermoplastic or thermosett ...
: Durable and low cost, acrylic is a non-corrosive material suitable for grinding salt and spices.
Electric grinders
Electric burr grinders are powered by
electricity
Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described ...
from a
battery
Battery most often refers to:
* Electric battery, a device that provides electrical power
* Battery (crime), a crime involving unlawful physical contact
Battery may also refer to:
Energy source
*Automotive battery, a device to provide power t ...
or mains supply.
An
electric motor
An electric motor is an Electric machine, electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a Electromagneti ...
drives the grinding elements against each other. Electric grinders grind faster than manual grinders with no effort, but friction and waste heat from the motor may heat the ground product slightly.
See also
*
*
Salt and pepper shakers
Salt and pepper shakers or salt and pepper pots, of which the first item is normally called a salt cellar in British English, are condiment dispensers used in Western culture that are designed to allow diners to distribute grains of edible sa ...
– for salt grains and pre-ground peppercorns
References
Further reading
*
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Articles containing video clips
Food grinding tools
Food preparation appliances
Grinding mills