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

blender A blender (sometimes called a mixer (from Latin ''mixus, the PPP of miscere eng. to Mix)'' or liquidiser in British English) is a kitchen and laboratory appliance used to mix, crush, purée or emulsify food and other substances. A stationary ...

s (including

immersion blender An immersion blender, also known as a stick blender, mini blender, hand blender, or wand blender, is a kitchen blade grinder used to blend ingredients or purée food in the container in which they are being prepared. The immersion blender was in ...

s),

food processor A food processor is a kitchen appliance used to facilitate repetitive tasks in the preparation of food. Today, the term almost always refers to an electric-motor-driven appliance, although there are some manual devices also referred to as "food ...

s, some garbage disposals, and some coffee grinders. The terms "blade grinder" and "propeller grinder" are in popular use to distinguish the blade grinder type of coffee grinder from other types. Other

consumer A consumer is a person or a group who intends to order, or use purchased goods, products, or services primarily for personal, social, family, household and similar needs, who is not directly related to entrepreneurial or business activities. ...

applications include rotary

lawn mower A lawn mower (also known as a grass cutter or simply mower, also often spelled lawnmower) is a device utilizing one or more revolving blades (or a reel) to cut a lawn, grass surface to an even height. The height of the cut grass may be fixed by ...

Design

A blade grinder may be considered a type of hammermill. A blade grinder resembles a meat grinder in that both have

propeller A propeller (often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon a working flu ...

-shaped cutting blades. However, meat grinders (and

food mill A food mill (also called passatutto, purée sieve, moulinette, mouli légumes, passe-vite, or triturator) is a food preparation utensil for wikt:Mash, mashing and sieve, sieving soft foods invented in Brussels in 1928 by Victor Simon. Typicall ...

s) use a scissor cutting action as the blades rotate against a perforated metal plate. Meat grinder blades rotate at a much slower speed than blade grinders, which may rotate at speeds as high as 20,000 to 30,000

rpm Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or r⋅min−1) is a unit of rotational speed (or rotational frequency) for rotating machines. One revolution per minute is equivalent to hertz. Standards ISO 80000-3:2019 def ...

; for example, the Steele model mixer-grinder by Indian appliance manufacturer Preethi has a no-load speed of 23,500 rpm and loaded speed of 11,500rpm. Blade grinders also resemble industrial blade (propeller) mixers, which like meat grinders rotate at much slower speeds. Unlike blade grinders, these mixers do not alter (break, cut, shred, macerate, pulverize) the material being mixed. The high speed of rotation of blade grinders is necessary to achieve their cutting action. In a blender application, the high speed of rotation contributes to

shearing Sheep shearing is the process by which the woollen fleece of a sheep is cut off. The person who removes the sheep's wool is called a '' shearer''. Typically each adult sheep is shorn once each year (depending upon dialect, a sheep may be sai ...

, which in turn contributes to

aeration Aeration (also called aerification or aeriation) is the process by which air is circulated through, mixed with or dissolved in a liquid or other substances that act as a fluid (such as soil). Aeration processes create additional surface area in t ...

and the formation of

emulsion An emulsion is a mixture of two or more liquids that are normally Miscibility, immiscible (unmixable or unblendable) owing to liquid-liquid phase separation. Emulsions are part of a more general class of two-phase systems of matter called colloi ...

s. These are desirable qualities in many food preparations. A blade grinder can run on batteries or more commonly on utility electricity.

History

Blade grinders are a 20th-century innovation that followed the adaptation of propellers to small

motorboat A motorboat or powerboat is a boat that is exclusively powered by an engine; faster examples may be called "speedboats". Some motorboats are fitted with inboard engines, others have an outboard motor installed on the rear, containing the inter ...

s. Blade grinders exploit a feature of propellers that is undesirable in the propulsion systems of boats and airplanes: the higher the rotation speed, the more energy is spent in shearing and cutting rather than in pushing. Rotary lawn mowers were not developed until small engines became powerful enough to run the blades at a speed high enough to cut. Commercial blenders were developed in the 1920s. With increasing miniaturization of the electric motor, the first consumer blender, the Waring Blendor, was developed in the 1930s, and a canister blender, the Osterizer, entered the market in 1946. The first immersion blenders were patented in the 1950s.

Types

Coffee grinders

Special purpose coffee grinders usually are either blade grinders or burr grinders: blade grinders being less expensive and having additional uses, burr grinders giving a better quality of grind. Special purpose spice grinders usually are either blade grinders or

mortar and pestle A mortar and pestle is a set of two simple tools used to prepare ingredients or substances by compression (physics), crushing and shear force, grinding them into a fine Paste (rheology), paste or powder in the kitchen, laboratory, and pharmacy. ...

(or related tools). Low cost coffee blade grinders for use in home kitchens frequently are difficult to clean. '' The Joy of Cooking'' (1997 edition) suggests a blade grinder may be cleaned by grinding a few tablespoons of sugar then wiping it out. Another suggestion is to clean around the blade with a soft brush or a damp cloth. Because these blade grinders frequently are used for grinding both coffee beans and spices, cleaning them well is important to prevent unwanted transfer of flavors. Some people keep two blade grinders, one for coffee and the other for spices.

Pharmacy, restaurant, and laboratory grinders

Blade grinders for home grinding of coffee beans are commonly used for grinding spices. However, larger, more powerful versions are used, particularly in Asia. Commonly found in pharmacies in China for grinding Chinese traditional medicine, the blades of this style of grinder can rotate at 28,000 rpm or more and are capable of reducing hard dried roots to powder. This type of grinder is also used in restaurants for spices as well as for laboratory use.

Blenders

Blenders are blade grinders designed specifically for use with wet ingredients. Blenders are popular tools for production of

purée A purée (or mash) is cooked food, usually vegetables, fruits or legumes, that has been ground, pressed, blended or sieved to the consistency of a creamy paste or liquid. Purées of specific foods are often known by specific names, e.g., appl ...

s and pastes, using both the cutting and shearing effects of high speed blades.

Food processor

A food processor is similar to a blender. The primary difference is that food processors use interchangeable blades and disks (attachments) rather than a fixed blade. Also, their bowls are wider and shorter, a more proper shape for the solid or semi-solid foods usually worked in a food processor. File:Blade grinder used to separate cardamom seeds from pods.jpg, Blade grinder used to separate

cardamom Cardamom (), sometimes cardamon or cardamum, is a spice made from the seeds of several plants in the genus (biology), genera ''Elettaria'' and ''Amomum'' in the family Zingiberaceae. Both genera are native to the Indian subcontinent and Indon ...

seeds from pods File:Kitchen blender blades.png, Blades from a blender (left) and food processor (right)

References

External links

* * https://bestcoffeemakes.com {{DEFAULTSORT:Blade Grinder Food grinding tools Food preparation appliances Propellers