Ceramic

Ultimately these ceramic materials may be used as bone replacements or with the incorperation of protein collagens, synthetic bones. Large coffee shop chains may have a policy of composting coffee grounds or giving them away to those who ask. Work is being done to make strong-fully dense nano crystalline Hydroxapatite ceramic materials for orthopedic weight bearing devices, replacing foreign metal and plastic orthopedic materials with a synthetic natural bone mineral. Coffee grounds can be obtained inexpensively (usually free) from local coffee shops. They are also used as fillers for orthopedic plastic screws to aid in reducing the inflammation and increase absorption of these plastic materials. When added to a compost pile, spent coffee grounds compost very rapidly. Most Hydroxyapatite ceramics are very porous and lack mechanical strength and are used to coat metal orthopedic devices to aid in forming a bond to bone or as bone fillers. Many gardeners report that roses love coffee grounds and when furnished with the same become big and colorful.

Because of this, they are of great interest for gene delivery and tissue engineering scaffolds. Coffee grounds also contain potassium, phosphorus, and many other trace elements that aid plant development. Orthopedic implants made from these materials bond readily to bone and other tissues in the body without rejection or inflammatory reactions. Spent coffee grounds are a good fertilizer in gardens because of their high nitrogen content. Hydroxyapatite, the natural mineral componet of bone, has been made synthetically from a number of biological and chemical sources and can be formed into ceramic materials. Filtered coffee only contains trace amounts of cafestol. Recently, there have been advances in ceramics which include bio-ceramics, such as dental implants and synthetic bones. A study has shown that cafestol, a substance which is present in boiled coffee drinks, dramatically increases cholesterol levels, especially in women.

Very similar technology is used for armoring of cockpits of some military airplanes, because of the low weight of the material. One variable is the type of decaffeination process used; while some involve the use of organic solvents which may leave residual traces, others rely on steam. Such plates are known commonly as small-arms protective inserts (SAPI). The health risks of decaffeinated coffee have been studied, with varying results. Since the late 1990s highly specialized ceramics, usually based on boron carbide, formed into plates and lined with Spectra, have been used in ballistic armored vests to repel large-caliber rifle fire. This is a detrimental effect of coffee on the cardiovascular system, which may explain why coffee has so far only been shown to help the heart at levels of four cups (20 fl oz or 600 mL) or fewer per day. Turbine engines made with ceramics could operate more efficiently, giving aircraft greater range and payload for a set amount of fuel. The study concluded that consumption of coffee is associated with significant elevations in biochemical markers of inflammation.

Currently, even blades made of advanced metal alloys used in the engines' hot section require cooling and careful limiting of operating temperatures. The American Journal of Clinical Nutrition published a study in 2004 which tried to discover why the beneficial and detrimental effects of coffee are conflicting. Work is being done in developing ceramic parts for gas turbine engines. Women still worried about chemical solvents in decaffeinated coffee should opt for beans which use the Swiss water process, where no chemicals other than water are used, although higher amounts of caffeine remain. Such engines are possible in laboratory settings, but mass-production is infeasible with current technology. As such, these chemicals, namely trichloroethane and methylene chloride, are present in trace amounts at most, and neither pose a significant threat to unborn children. Imperfection in the ceramic leads to cracks, which can lead to potentially dangerous equipment failure. These concerns have almost no basis, however, as the solvents in question evaporate at 80–90 °C, and coffee beans are decaffeinated before roasting, which occurs at approximately 200 °C.

Despite all of these desirable properties, such engines are not in production because the manufacturing of ceramic parts in the requisite precision and durability is difficult. Decaffeinated coffee is occasionally regarded as a potential health risk to pregnant women, due to the high incidence of chemical solvents used to extract the caffeine. In a conventional metallic engine, much of the energy released from the fuel must be dissipated as waste heat in order to prevent a meltdown of the metallic parts. This study has not yet been repeated, but has caused some doctors to caution against excessive coffee consumption during pregnancy. Fuel efficiency of the engine is also higher at high temperature. fl oz or 1.4 L) were at 220% increased risk compared with nondrinkers. Ceramic engines do not require a cooling system and hence allow a major weight reduction and therefore greater fuel efficiency. Those who drank eight or more cups a day (48 U.S.

A couple of decades ago, Toyota researched production of an adiabatic ceramic engine which can run at a temperature of over 6000 °F (3300 °C). "The results seem to indicate a threshold effect around four to seven cups per day," the study reported. This results in shorter sintering times compared to solid state sintering. A February 2003 Danish study of 18,478 women linked heavy coffee consumption during pregnancy to significantly increased risk of stillbirths (but no significantly increased risk of infant death in the first year). If a mixture of different materials is used together in a ceramic, the sintering temperature is sometimes above the melting point of one minor component - a liquid phase sintering. fl oz or 1.4 L or more). Indeed, traditional pottery is done with this type of method, using a plastic mixture worked with the hands. There are also gender-specific effects, in some PMS sufferers it increases the symptoms, and it can reduce fertility in women, also it may increase the risk of osteoporosis in postmenopausal women, and there may be risks to a fetus if a pregnant woman drinks 8 or more cups a day (48 U.S.

A slurry can be used in place of a powder, and then cast into a desired shape, dried and then sintered. It can also cause anxiety and irritability, in some with excessive coffee consumption, and some as a withdrawal symptom. Shanefield, Kluwer Publishers [Boston], 1996. Coffee can also cause insomnia in some, while paradoxically it helps a few sleep more soundly. J. Coffee can also increase blood pressure among those with high blood pressure, but follow-up studies showed that coffee still decreased the risk of dying from heart disease in the aggregate. [Westerville, Ohio], 2000.) A comprehensive book on the subject, for mechanical as well as electronics applications, is "Organic Additives and Ceramic Processing," by D. Many coffee drinkers are familiar with "coffee jitters", a nervous condition that occurs when one has had too much caffeine.

Ceramic Soc. Many notable effects of coffee are related to its caffeine content. Mistler, et al., Amer. Practitioners in alternative medicine often recommend coffee enemas for "cleansing of the colon" due to its stimulus of peristalsis, although mainstream medicine has not proved any benefits of the practice. The specialized formulations most commonly used in electronics are detailed in the book "Tape Casting," by R.E. Therefore it has been variously suggested that the cognitive effects of caffeine are limited to those who have not developed a tolerance, or to those who have developed a tolerance and are caffeine-deprived. This is particularly important in the manufacture of high performance ceramics such as those used by the billions for electronics, in capacitors, inductors, sensors, etc. Some controversy over these effects exists, since by its nature coffee consumption is associated with other behavioral variables.

(The formulation of these organic chemical additives is an art in itself. fl oz or 0.95 L or more). It is not uncommon to combine these, and add binders and lubricants to a powder, then press. fl oz, 700 mL), but others occur at 5 or more cups a day (32 U.S. Sometimes organic lubricants are added during pressing to increase densification. Some of these health effects are realized by as little as 4 cups a day (24 U.S. Sometimes organic binders such as polyvinyl alcohol are added to hold the green body together; these burn out during the firing (at 200-350°C). It also changes the metabolism of a person so that their body burns a higher proportion of lipids to carbohydrates, which can help athletes avoid muscle fatigue.

Some of the most common involve pressing the green body to give the densification a head start and reduce the sintering time needed. Many people drink coffee for its ability to increase short term recall and increase IQ. There are thousands of possible refinements of this process. However, coffee can also cause loose bowel movements. This makes it a very versatile route. Coffee is also a powerful stimulant for peristalsis and is sometimes considered to prevent constipation; it is also a diuretic. There is virtually always some porosity left, but the real advantage of this method is that the green body can be produced in any way imaginable, and still be sintered. 6.

The firing is done at a temperature below the melting point of the ceramic. It is present in both caffeinated and decaffeinated coffee, and even in instant coffee. The pores in the object close up, resulting in a denser, stronger product. Methylpyridinium is not present in raw coffee beans but is formed during the roasting process from trigonellin, which is common in raw coffee beans. Once a roughly held together object (called a "green body") is made, it is baked in a kiln, where diffusion processes cause the green body to shrink. This compound is not present in significant amounts in other food materials. The principles of sintering-based methods is simple. Coffee contains the anticancer compound methylpyridinium.

These tend to produce very dense ceramics, but do so slowly. At the annual meeting of the American Chemical Society in Washington, D.C., on August 28, 2005, chemist Joe Vinson of the University of Scranton presented his analysis showing that for Americans, who as a whole do not consume large quantities of fresh fruits and vegetables, coffee represents by far the largest source of valuable antioxidants in the diet.[4]. This borrows techniques from the semiconductor industry, such as chemical vapour deposition, and is very useful for coatings. Also, coffee reduces the incidence of heart disease, though whether this is simply because it rids the blood of excess fat or because of its stimulant effect is unknown. However, small-scale systems can be made by deposition techniques, where the various materials are introduced above a substrate, and react and form the ceramic on the substrate. Coffee can reduce the risk of hepatocellular carcinoma, a variety of liver cancer (Inoue, 2005). The biggest problem with this method is that most reactions are so fast that good mixing is not possible, which tends to prevent large-scale construction. Coffee can also reduce the incidence of cirrhosis of the liver and prevent colon and bladder cancers.

Over time, these result in a solid ceramic. While this was originally noticed in patients who consumed high amounts (7 cups a day), the relationship was later shown to be linear (Salazar-Martinez 2004). This starts hydration reactions, which result in long, interlocking crystals forming around the aggregates. Coffee intake may reduce one's risk of diabetes mellitus type 2 by up to half. Here, the dehydrated powders are mixed with water. Some of the beneficial effects may be restricted to one sex, for instance it has been shown to reduce the occurrence of gallstones and gallbladder disease in men. The most common use of this method is in the production of cement and concrete. For this reason some aspirin producers also include a small dose of caffeine in the pill.

A few methods use a hybrid between the two approaches. Coffee increases the effectiveness of pain killers—especially migraine medications—and can rid some people of asthma. Methods for dealing with them tend to fall into one of two categories - either make the ceramic in the desired shape, by reaction in situ, or by forming powders into the desired shape, and then sintering to form a solid body. See the caffeine article for more on the pharmacological effects of caffeine. Crystalline ceramic materials are not amenable to a great range of processing. Caffeine dependence is widespread and withdrawal symptoms are real. If later heat-treatments cause this class to become partly crystalline, the resulting material is known as a glass-ceramic. There are also tisanes that resemble coffee in taste but contain no caffeine (see below).

The glass is shaped when either fully molten, by casting, or when in a state of toffee-like viscosity, by methods such as blowing to a mould. Decaffeinated coffee usually loses some flavor over normal coffees and tends to be more bitter. Non-crystalline ceramics, being glasses, tend to be formed from melts. Extraction with supercritical carbon dioxide has also been employed. Titanates with critical temperatures far below room temperature have become synonymous with "ceramic" in the context of ceramic capacitors for just this reason. Another solvent used is ethyl acetate; the resultant decaffeinated coffee is marketed as "natural decaf" due to ethyl acetate being naturally present in fruit. While a lack of temperature control would rule out any practical use of the material near its critical temperature, the dielectric effect remains exceptionally strong even at much higher temperatures. This is coffee from which most of the caffeine has been removed, by the Swiss water process (which involves the soaking of raw beans to absorb the caffeine) or the use of a chemical solvent such as trichloroethylene ("tri"), or the more popular methylene chloride, in a similar process.

At the transition temperature, the material's dielectric response becomes theoretically infinite. For occasions when one wants to enjoy the flavor of coffee with less stimulation, decaffeinated coffee (also called decaf) is available. Such ceramics are used as self-controlled heating elements in, for example, the rear-window defrost circuits of most automobiles. Coffee contains an as yet unknown chemical agent which stimulates the production of cortisone and adrenaline, two stimulating hormones. In such materials, current will pass through the material until joule heating brings it to the transition temperature, at which point the circuit will be broken and current flow will cease. Recent research has uncovered additional stimulating effects of coffee which are not related to its caffeine content. The critical transition temperature can be adjusted over a wide range by variations in chemistry. Many office workers take a "coffee break" when their energy is diminished.

Increases in temperature can cause grain boundaries to suddenly become insulating in some semiconducting ceramic materials, mostly mixtures of heavy metal titanates. Students preparing for examinations with late-night "cram sessions" use coffee to maintain their concentration. Aside from the uses mentioned above, their strong piezoelectric response is exploited in the design of high-frequency loudspeakers, transducers for sonar, and actuators for atomic force and scanning tunneling microscopes. For this reason, it is often consumed in the morning, and during working hours. The most common such materials are lead zirconate titanate and barium titanate. Coffee contains caffeine, which acts as a stimulant. This can be used to store information in ferroelectric capacitors, elements of ferroelectric RAM. Fairtrade labelling is becoming more popular in many developed countries, allowing consumers to ensure that co-operative producers receive a viable minimum price for their goods.

Pyroelectricity is also a necessary consequence of ferroelectricity. (Mai, 2006). In turn, pyroelectricity is seen most strongly in materials which also display the ferroelectric effect, in which a stable electric dipole can be oriented or reversed by applying an electrostatic field. Prices are expected to either remain constant or rise in 2006. Such materials are used in motion sensors, where the tiny rise in temperature from a warm body entering the room is enough to produce a measurable voltage in the crystal. Many coffee bean farmers can now live off their products, but not all of the extra-surplus trickles down to them, because rising petroleum prices make the transportation, roasting and packaging of the coffee beans more expensive. These materials can be used to interconvert between thermal, mechanical, and/or electrical energy; for instance, after synthesis in a furnace, a pyroelectric crystal allowed to cool under no applied stress generally builds up a static charge of thousands of volts. This rise was likely caused by an increase in consumption in Russia and China as well as a harvest which was about 10% to 20% lower than that in the record years before.

The piezoelectric effect is generally stronger in materials that also exhibit pyroelectricity, and all pyroelectric materials are also piezoelectric. In 2005, however, the coffee prices rose. The unit of time measured is the natural interval required for electricity to be converted into mechanical energy and back again. According to the Specialty Coffee Association of America, in 2004 16% of adults in the United States drank specialty coffee daily; the number of retail specialty coffee locations, including cafes, kiosks, coffee carts and retail roasters, amounted to 17,400 and total sales were $8.96 billion in 2003. Such devices use both properties of piezoelectrics, using electricity to produce a mechanical motion (powering the device) and then using this mechanical motion to produce electricity (generating a signal). Ironically, the decline in the ingredient cost of green coffee, while not the only cost component of the final cup being served, was paralleled by the rise in popularity of Starbucks and thousands of other specialty cafes, which sold their beverages at unprecedented high prices. Piezoelectricity, a link between electrical and mechanical response, is exhibited by a large number of ceramic materials, including the quartz resonators used as to measure time watches and other electronics. (Mai, 2006).

The exact reason for this is not known, but there are two major families of superconducting ceramics. The market awarded the more efficient Vietnamese coffee suppliers with trade and caused less efficient coffee bean farmers in many countries such as Brazil, Nicaragua, and Ethiopia not to be able to live off of their products, forcing many to quit the coffee bean production and move into slums in the cities. Under some conditions, such as extremely low temperature, some ceramics exhibit superconductivity. Coffee prices had been falling for about a decade until 2004: among the reasons for this decline included the expansion of Brazilian coffee plantations and Vietnam's entry into the market in 1994 when the United States trade embargo against it was lifted. With tuning to the possible gas mixtures, very inexpensive devices can be produced. This is where coffee futures contracts, a financial asset involving a standardized contract for the future sale or purchase of a unit of coffee at an agreed price, are traded. When various gases are passed over a polycrystalline ceramic, its electrical resistance changes. Coffee is also bought and sold as a commodity on the New York Coffee, Sugar, and Cocoa Exchange.

Semiconducting ceramics are also employed as gas sensors. For instance, in Brazil alone, where almost a third of all the world's coffee is produced, over 5 million people are employed in the cultivation and harvesting of over 3 billion coffee plants; it is a much more labour-intensive culture than alternative cultures of the same regions as soy, sugar cane, wheat or cattle, as it is not subject to automation and requires constant attention. They have rapid response, are low maintenance, and do not appreciably degrade from use, making them virtually ideal devices for this application. Worldwide, 25 million small producers rely on coffee for a living. The best demonstration of their ability can be found in electrical substations, where they are employed to protect the infrastructure from lightning strikes. With over 400 billion cups consumed every year, coffee is the world's most popular beverage. As there is control over the threshold voltage and energy tolerance, they find use in all sorts of applications. Coffee is one of the world's most important primary commodities; it ranks second only to petroleum in terms of dollars traded worldwide.

This makes them ideal for surge-protection applications. See also dunk (biscuit) for the habit of dipping a biscuit (cookie) or cake into a coffee. The major advantage of these is that they can dissipate a lot of energy, and they self reset — after the voltage across the device drops below the threshold, its resistance returns to being high. This has encouraged customers, especially from the working world, to relax over a cup of coffee and eat something while being able to check their e-mail and surf the Web all from the comfort of their seat. Once the voltage across the device reaches a certain threshold, there is a breakdown of the electrical structure in the vicinity of the grain boundaries, which results in its electrical resistance dropping from several megaohms down to a few hundred ohms. In recent years, cafés have begun to offer wireless Internet (Wi-Fi) connectivity to attract customers. These are devices that exhibit the unusual property of negative resistance. This is ironic in that coffee is a stimulant.

One of the most widely used of these is the varistor. Contemporary advertising tends to equate the term "coffee break" with rest and relaxation. While there is talk of making blue LEDs from zinc oxide, ceramicists are most interested in the electrical properties that show grain boundary effects. Social habits involving coffee in offices include the morning chat over coffee and the coffee break. Most of these are transition metal oxides that are II-VI semiconductors, such as zinc oxide. Because of the stimulant properties of coffee and because coffee does not adversely impact higher mental functions, coffee is strongly associated with white collar jobs and office workers. There are a number of ceramics that are semiconductors. Besides coffee, the host or hostess at the coffee party also serves cake and pastries, hopefully homemade.

It is therefore neglected in many applications of ceramic materials. In some countries, notably in northern Europe, coffee parties are a popular form of entertaining. With the non-crystalline (glassy) materials, viscous flow is the dominant source of plastic deformation, and is also very slow. Some shops are miniature cafés that specialise in coffee-to-go for hurried travelers, who may visit these on their way to work as a substitute for breakfast. However, due to the rigid structure of the crystalline materials, there are very few available slip systems for dislocations to move, and so they deform very slowly. Most cafés also serve tea, sandwiches, pastries, and other light refreshments. These materials do show plastic deformation. Coffee is so popular in the Americas, the Middle East, and Europe that many restaurants specialize in coffee; these are called "coffeehouses" or "cafés".

These combine to give catastrophic failures, as opposed to the normally much more gentle failure modes of metals. However, consumption has also vastly increased in the United Kingdom in recent years. Additionally, because these materials tend to be porous, the pores and other microscopic imperfections act as stress concentrators, decreasing the toughness further, and reducing the tensile strength. Finland consumes the most coffee per capita, an average of four to five cups a day. A material held together by either type of bond will tend to fracture before any plastic deformation takes place, which results in poor toughness in these materials. The United States is the largest market for coffee, followed by Germany. Ceramic materials are usually ionic or covalently-bonded materials, and can be crystalline or amorphous. The machines used to process it can handle up to 500 cups an hour, or 1,000 if the water is preheated.^[3].

Each one of these classes can develop unique material properties. Its primary use is in large institutional situations where coffee needs to be produced for thousands of people at the same time. Technical Ceramics can also be classified into three distinct material categories:. It costs about 10 cents a cup to produce. . It is described as having a flavor about as good as low-grade robusta coffee. In Commonwealth English, ceramic can also be used as a singular noun, referring to an object made of ceramic material. Another type of premade coffee is liquid coffee concentrate.

Ceramics is a singular noun referring to the art of making things out of ceramic materials. Other premade coffee drinks are also commercially available, but tend to be less popular. The word ceramic can be an adjective, and can also be used as a noun to refer to a ceramic material. They also sell a canned espresso drink, Double Shot, lightly sweetened and blended with cream. The study of ceramics consists to a large extent of methods to mitigate these problems, and accentuate the strengths of the materials, as well as to offer up unusual uses for these materials. In the United States, Starbucks sells its popular Frappuccino drinks in glass bottles, a beverage consisting primarily of milk, coffee, sugar, and flavoring (like vanilla or caramel). Historically, ceramic products have been hard, porous and brittle. Japanese convenience stores and groceries also have a wide availability of plastic-bottled coffee drinks, which typically are lightly sweetened and pre-blended with milk.

A composite material of ceramic and metal is known as cermet. To match with the often busy life of Korean city dwellers, companies mostly have canned coffee with a wide variety of tastes. The traditional crafts are described in the article on pottery. Vending machines typically sell a number of varieties of canned coffee, available both hot and cold. Up until the 1950s or so, the most important of these were the traditional clays, made into pottery, bricks, tiles and the like, along with cements and glass. Canned coffee is a beverage that has been popular in Asian countries for many years, particularly in Japan and South Korea. The term covers inorganic non-metallic materials whose formation is due to the action of heat. Instant and soluble coffee has been dried into soluble powder or granules, which can be quickly dissolved in hot water for consumption.

The word ceramic is derived from the Greek word κεραμικος (keramikos, "having to do with pottery"). Connoisseurs shun such conveniences as compromising the flavor of the coffee; they prefer freshly ground beans and traditional brewing techniques. In another variant, metastable structures can impart transformation toughening for mechanical applications; most ceramic knife blades are made of this material. Some even grind the beans automatically before brewing. Its high oxygen ion conductivity recommends it for use in fuel cells. Electronic coffee makers boil the water and brew the infusion with little human assistance and sometimes according to a timer. Zirconia, which in pure form undergoes many phase changes between room temperature and practical sintering temperatures, can be chemically "stabilized" in several different forms. However, if it is kept in an oxygen-free environment it can last almost indefinitely at room temperature, and sealed containers of brewed coffee are sometimes commercially available in food stores in America or Europe.

Zinc oxide (ZnO), which is a semiconductor, and used in the construction of varistors. For this reason aficionados frown upon the hotplate which is sometimes used to keep brewed coffee warm prior to serving. Yttrium barium copper oxide (YBa₂Cu₃O_7-x), another high temperature superconductor. Brewed coffee continually heated will deteriorate rapidly in flavor; even at room temperature, deterioration will occur. Uranium oxide (UO₂), used as fuel in nuclear reactors. The usual ratio of coffee to water for the style of coffee most prevalent in Europe, America, and other Westernized nations is between one and two tablespoons of ground coffee per six ounces (180 millilitres) of water; the full two tablespoons per six ounces tends to be recommended by experienced coffee lovers. Steatite is used as an electrical insulator. If the water is too hot, some undesirable elements will be extracted, adversely affecting the taste, especially in bitterness.

Silicon nitride (Si₃N₄), which is used as an abrasive powder. Any cooler and some of the solubles that make up the flavor will not be extracted. Silicon carbide (SiC), which is used as a susceptor in microwave furnaces, a commonly used abrasive, and as a refractory material. The recommended brewing temperature of coffee is 93 °C (204 °F). Porcelain, which usually contains the clay mineral kaolinite. Water temperature is crucial to the proper extraction of flavor from the ground coffee. Magnesium diboride (MgB₂), which is an unconventional superconductor. The fineness of the grind required differs by the method of extraction.

Lead zirconate titanate is another ferroelectric material. Coffee in all these forms is made with coffee grounds (coffee beans that have been roasted and ground) and hot water, the grounds either remaining behind or being filtered out of the cup or jug after the main soluble compounds have been removed. Ferrite (Fe₃O₄), which is ferrimagnetic and is used in the core of electrical transformers and magnetic core memory. If the method allows the water to pass only once through the grounds, the resulting brew will contain mainly the more soluble components (including caffeine), whereas if the water is repeatedly cycled through the beans (as with the common percolator), the brew will contain more of the relatively less soluble compounds found in the bean; as these tend to be more bitter, that type of process is less favored by coffee aficionados. Earthenware, which is often made from clay, quartz and feldspar. Coffee can be brewed in several different ways, but these methods fall into four main groups depending upon how the water is introduced to the coffee grounds. Bricks (mostly aluminium silicates), used for construction. There are two methods of producing coffee grounds ready for brewing.

Boron_nitride is structurally isoelectronic to carbon and takes on similar physical forms: a graphite-like one used as a lubricant, and a diamond-like one used as an abrasive. With the rise of coffee as a gourmet beverage, it has become much more popular to grind the beans at home before brewing, and there are many home appliances available which are dedicated to the process. Boron carbide (B₄C), which is used in some helicopter and tank armor. The rate of deterioration increases when the coffee is ground, as a result of the greater surface area exposed to oxygen. Bismuth strontium calcium copper oxide, a high-temperature superconductor. At the other extreme, an overly coarse grind will produce a weak, watery, under-flavored result. Grain boundary conditions can create PTC effects in heating elements. Beans which are too finely ground for the brewing method in which they are used will expose too much surface area to the heated water and produce a bitter, harsh, "over-extracted" taste.

It is widely used in electromechanical transducers, ceramic capacitors, and data storage elements. Brewing methods which expose coffee grounds to heated water for a longer duration of time require a coarser grind than faster brewing methods. Barium titanate (often mixed with strontium titanate) displays ferroelectricity, meaning that its mechanical, electrical, and thermal responses are coupled to one another and also history-dependent. The fineness of the grounds has a major impact on the brewing process, and matching the consistency of the grind with the brewing method is critical to extracting the optimal amount of flavor from the roasted beans. Composites: Particulate reinforced, combinations of oxides and non-oxides. However, as is said in the coffee industry, "the proof is in the cup.". Non-oxides: Carbides, borides, nitrides, silicides. Some companies have tried to extend the freshness using a nitrogen-infusion system that flushes the inert gas into the roasted coffee, replacing the oxygen, ostensibly reducing oxidation.

Oxides: Alumina, zirconia. Despite the varying claims of "what is fresh" when it comes to coffee, the industry leaders in specialty coffee generally agree that roasted coffee should be ground and brewed no more than about 14 days off-the-roast. Once roasted, the volatile compounds that give coffee its complex flavors dissipate quickly. This CO₂ also affects the flavor of the brewed coffee, and most experts recommend a two- to five-day "resting" period post-roast for the CO₂ to sufficiently escape. For this reason, many roasters who package whole beans immediately after roasting do so in bags with one-way valves, allowing the CO₂ to escape but nothing in.

Because coffee emits CO₂ for days after it is roasted, one must allow the coffee to degas before it can be packaged in sealed containers. Computerized drum roasters are available which simplify homeroasting, and some home roasters will simply roast in an oven or in air popcorn makers. Today homeroasting is becoming popular again. This form of roasting requires much skill to do well, and fell out of favor when vacuum sealing of pre-roasted coffee became possible.

In the 19th century coffee was usually bought in the form of green beans and roasted in a frying pan. In the United States, major national coffee suppliers tailor their product to tastes in particular regions of the country; for instance, a can of ground coffee purchased in the northeast or northwest will contain a darker roast than an identically appearing can purchased in the central United States. Contrary to popular belief, the darker roasts and more strongly flavored coffees do not deliver any more caffeine than lighter roasts. The dividing line between extremely dark roast and "burnt" is a matter of some debate.

These roasts are sold by the degree of roast, ranging from "Vienna Roast" to "French Roast" and beyond. At darker roasts, the "roast flavor" is so dominant that it can be difficult to distinguish the origin of the beans used in the roast. As the beans darken to a deep brown, the origin flavors of the bean are eclipsed by the flavors created by the roasting process itself. A roasting method native to the Ipoh town in Malaysia involves the inclusion of margarine (palm oil-derived) and sugar during the roasting process, producing a variety of roast known as the Ipoh "white" coffee.

Coffee beans from famous regions like Java and Kenya are usually roasted lightly so their signature characteristics dominate the flavor. At lighter roasts, the bean will exhibit more of its "terroir" —the flavors created in the bean by the soil and weather conditions in the location where it was grown. The beans will continue to darken and the oils will begin to be expelled to the surface until the beans are removed from the heat source. "First crack" and "second crack" are benchmarks that a roaster will use to gauge how the roast progresses.

Coffee beans will crack during the roasting process, not unlike popping popcorn. This oil contains the distinctive compounds which give coffee its flavor; the more oil released, the stronger the flavor. When the inside of the bean reaches about 400 degrees Fahrenheit, it begins to turn brown and the oil is released from the interior of the bean. During this stage the moisture in the beans is expelled.

As the bean absorbs heat, the color shifts to yellow and then to a light "cinnamon" brown. When roasted, the green coffee bean expands to nearly double its original size, changing in color and density. The roasting process is integral to producing a savory cup of coffee. However, most coffee experts agree that a green coffee peaks in flavor and freshness within one year of harvest, because over-aged coffee beans will lose much of their essential oil content.

Several of these coffee producers sell coffee beans that have been aged for as long as 3 years, with some as long as 8 years. Although it is still widely debated, certain types of green coffee are believed to improve with age; especially those that are valued for their low acidity, such as coffees from Indonesia or India. Automatic sorting is cost-effective for large producers where quantity and throughput are important factors in production. Elsewhere, beans are sorted automatically by sophisticated machines that employ CCD cameras and can determine both size and color.

In many less developed countries, hand sorting is still done because of the low cost of labor. Discoloured, rotten, and damaged beans are also removed at this point. The first step in preparation is sorting of beans by color and size. At this stage, the beans are referred to as "green coffee".

The beans are repeatedly raked into rows and spread out over the course of several days until they are largely dry. Coffee beans are spread over a large concrete or rock surface where they are dried by air and sunlight. Each produces its own flavour profile and each is, in essence, a different way of handling the process of defruiting the beans. Other coffee processing methods include the Pulped Natural process, the Indonesian "semi-washed" methods as well as aguapulping and re-fermentation.

This creates a unique flavour profile with reduced acidity and increased body, though if done poorly can lead to defect. Washed coffees tend to be described as "clean" and "bright." Coffees called "naturals" are those where the fruit is not immediately removed from the beans, but is instead allowed to dry and partially ferment. These coffees tend to rest in water (the "ferment" stage) for a set amount of time (depending on the origin and producer). The defruited coffee bean is flushed with water to remove clinging fruit and additional sugars before drying.

For "washed" coffees, after harvesting, the flesh of the coffee berry must be quickly removed by soaking, scouring and/or mechanical rubbing. The coffee berries are a type of drupe, with fruit flesh directly covering the coffee bean. As such coffee picking is one of the most important stages in coffee production, and is the chief determinant for the quality of the end product. Red berries, with its higher aromatic oil and lower organic acid content are more fragrant, smooth, and mellow.

Mixes of green and red berries, or just green berries, are used to produce cheaper mass consumer coffee beans, which are characterized by a displeasingly bitter/astringent flavour and a sharp greenish odour. This discernment typically only occurs with growers who harvest for higher end/specialty coffee where the pickers are paid better for their labour. Depending on the grower, coffee pickers are sometimes specifically instructed to not pick green coffee berries since the seeds in the berries are not fully formed or mature. An experienced coffee picker can collect up to 6-7 baskets a day.

As of 2003, payment per basket is between US$2.00 to $10 with the overwhelming majority of the labourers receiving payment at the lower end. Coffee berries are most commonly picked by hand by labourers who receive payment by the basketful. Much processing and human labour is required before coffee berries and its seed can be processed into roasted coffee with which most Western consumers are familiar. So-called Ethical coffee is produced or traded under specific conditions and guidelines, which are generally more environmentally friendly or economically equitable to the producers.

A number of classifications are used to label coffee produced under certain environmental or labor standards. Often these beans are blended with other, less expensive varieties and the suffix "blend" added to the labelling, such as "Blue Mountain blend" or "Kona blend" even though they only contain a small amount of the coffee mentioned. Jamaican Blue Mountain and Hawaiian Kona coffees are perhaps the most prominent examples. Some bean varieties are so well-known and so in-demand that they are far more expensive than others.

In addition to those blends sold commercially, many coffee houses have their own signature "house blends". Nowadays, the Mocha-Java blend is often blended with some other varieties to provide variety. The chocolate flavor notes peculiar to Mocha gave rise to the popular chocolate-flavored beverage, the Cafe Mocha, which may have been invented in circumstances where no Mocha beans were available. One of the oldest traditional blends is Mocha-Java, combining beans of the same name.

Coffees are often blended for balance and complexity, and many popular blendings exist. Some well-known arabica coffees include:. These are dependent on the local environment where the coffee plants are grown, their method of process, and the genetic subspecies or varietal.
Coffee beans from two different places usually have distinctive characteristics such as flavor (flavor criteria includes terms such as "citrus-like" or "earthy"), caffeine content, body or mouthfeel, and acidity.

The beans are collected from the droppings of the Common Palm Civet, whose digestive processes give it a distinctive flavor. One unusual and very expensive variety of robusta is the Indonesian Kopi Luwak and the Philippine Kape Alamid. Robusta coffees (traded in London at much lower prices than New York's Arabica) are preferred by large industrial clients (multinational roasters, instant coffee producers, etc.) because of their lower cost. In 1997 the "c" price of coffee in New York broke US$3.00/lb, but by late 2001 it had fallen to US$0.43/lb.

Many experts believe this giant influx of cheap green coffee led to the prolonged pricing crisis from 2001 to the present. The largest coffee exporting nation remains Brazil, but in recent years the green coffee market has been flooded by large quantities of robusta beans from Vietnam ^[2], due to low costs and to financing provided by the World Bank indirectly through the French Government. Coffee aficionados may even distinguish auctioned coffees by lot number. The modern coffee trade is much more specific about origin, labeling coffees by country, region, and sometimes even the producing estate.

Arabica coffees were traditionally named by the port they were exported from, the two oldest being Mocha, from Yemen, and Java, from Indonesia. In Italy many espresso blends are based on dark-roasted robusta. Good quality robustas are used as ingredients in some espresso blends to provide a better "crema" (foamy head), and to lower the ingredient cost. Compared to arabica, robusta tends to be more bitter, with a telltale "burnt rubber" aroma and flavor.

This has led to its use as an inexpensive substitute for arabica in many commercial coffee blends such as Folgers, Maxwell House and almost all instant coffee products. It is more susceptible to disease, and considered by professional cuppers to be greatly superior in flavor to Coffea canephora (robusta), which contains about twice as much caffeine—a natural insecticide (paralyzes and kills some of the insects that attempt to feed on the plant) and stimulant— and can be cultivated in environments where arabica will not thrive. It is thought to be indigenous to Ethiopia, but as the name implies it was first cultivated on the Arabian Peninsula. Coffea arabica is the older of them.

There are two main species of the coffee plant. It should kept in mind, however, "cafe" can most likely be a shortened form of "cafeteria," i.e., a place where meals are served. In South African English cafe can refer to a convenience store rather than a place where coffee or other beverages are served. There is also often a selection of desserts or light sandwiches and other snacks.

In French, Spanish, and German, a "café" is typically a place that serves a wide variety of beverages, usually several types of coffee, tea, and often alcoholic beverages. This usage of the word has also spread to other languages. Also, in the Netherlands, the word coffee shop is used for places where marijuana is sold (the reason being that one needs fewer permits for a coffee shop). In Dutch the word refers to a bar and is thus more associated with alcohol consumption.

In English, "cafe" refers mostly to places where meals are served, as well as coffee. The mother plant for much of the arabica coffee in the world is kept in the Amsterdam Hortus Botanicus. For many decades in the 19th and early 20th centuries Brazil was the biggest producer and virtual monopolist in the trade, until a policy of maintaing high prices opened opportunities to other growers, like Colombia, Guatemala and Indonesia. The success of coffee in 17th-century Europe was paralleled with the spread of the habit of tobacco smoking all over the continent during the course of the Thirty Years War (1618– 48).

The first coffee plantation in the New World was established in Brazil in 1727, and this country, like most others cultivating coffee as a commercial commodity, relied heavily on slave labor from Africa for its viability until abolition in 1888. Another more credible story is that the first coffeehouses were opened in Krakow in the 16th or 17th century because of closer trade ties with the East, most notably the Turks. Legend has it that the first coffeehouse opened in Vienna in 1683 after the Battle of Vienna, taking its supplies from the spoils left behind by the defeated Turks. Women were not allowed in coffeehouses, and in London, the anonymous 1674 "Women's Petition Against Coffee" complained:.

By 1675, there were more than 3,000 coffeehouses in England. Largely through the efforts of the British and Dutch East India companies, coffee became available in Europe in the 16th century, at the latest from Leonhard Rauwolf's 1583 account, with first coffeehouses opening in the mid-17th century: in Cornhill, London in 1652, in Boston in 1670, and in Paris in 1671. Coffee was introduced in England in the 1430s by the Greek professor in Oxford, Ioannis Servopoulos. In 1554, the first coffeehouse in Istanbul opened.

Consumption of coffee was outlawed in Mecca in 1511 and in Cairo in 1532, but in the face of its immense popularity, the decree was later rescinded. Qahwa originally referred to a type of wine, and need not be the name of the Kaffa region. A similar myth ascribes the discovery to an Ethiopian goatherd named Kaldi. When traveling in Ethiopia he observed goats of unusual vitality and, upon trying the berries that the goats had been eating, experienced the same effect.

One legendary account (though certainly a myth) is that of the Yemenite Sufi mystic named Shaikh ash-Shadhili. Coffee beans were first exported from Ethiopia to Yemen. One possible origin is the Kaffa region in Ethiopia, where the plant originated (its native name there being bunna). Its ultimate origin is uncertain, there being several legendary accounts of the origin of the drink.

The word entered English in 1598 via Italian caffè, via Turkish kahve, from Arabic qahwa. .
. Its potential benefits and hazards have been, and continue to be, widely studied and discussed.

Coffee is one of humanity's chief sources of caffeine, a stimulant. Coffee is the second most traded commodity in the world, trailing only petroleum. These seeds are usually called coffee beans, although they are not technically beans. Coffee is a drink, usually hot, prepared from the roasted seeds of the coffee plant.

Arfé. Latte art. Soy Coffee (e.g, Soyfee). During wartime, a grain substitute was made from grain, chicory and roasted acorns.

Teeccino). Herbal Coffee (e.g. Dandelion root. It is made from malted barley, chicory, and rye.

Pero, a coffee substitute from Switzerland. Postum. Chocolate-covered roasted coffee beans are available as a confection; unless the beans have been decaffeinated, these will deliver the same caffeine content as brewed coffee and have the same physiological effects. Spanish Coffee consists of Spanish brandy and hot coffee.

Mexican Coffee contains a 1/2 ounce of tequila, one ounce of coffee liqueur, and five ounces of hot coffee. Jamaican Coffee is served steaming with one ounce of coffee-flavored brandy and 3/4 ounce of light rum added to coffee. Italian Coffee consists of a 1/2 ounce of Amaretto, hot coffee, and 1 and 1/2 tablespoons of coffee ice cream. Irish Cream and coffee is a very popular drink, often served as an after dinner drink.

Irish coffee is made by adding 1 and 1/2 ounces of Irish Whiskey to a glass of black coffee, and then layering on 2-3cm of cream with a spoon. It is best presented when it is topped with whipped cream and chocolate shavings. Hot Kiss includes Creme de Menthe (white), one ounce Irish Whiskey, 1/2 ounce Creme de Cacao (white), and hot coffee. Handicapper's Choice consists of Irish Whiskey, Amaretto, and hot coffee.

It can be finished with a topping of whipped cream and chocolate shavings. Doublemint is made with 1 ounce of spearmint schnapps, hot coffee, and a dash of Creme de Menthe (green). Chocolate Coffee Kiss contains 1/4 oz coffee liqueur, 1/4 oz Irish cream liqueur, 1 splash of Creme de Cacao (brown), 1 splash of Mandarine Napoleon, 1 and 1/2 oz chocolate syrup, and hot coffee. Capriccio consists of 1 tbsp of sugar, 1/2 ounce brandy of choice, 1/2 ounce Creme de Cafe, 1 ounce of Amaretto, and hot coffee.

Caffè Corretto consists of a shot of espresso with an added shot of liquor, usually grappa or brandy. It is topped with whipped cream. Caffe Di Amaretto is simply prepared with one ounce of Amaretto and a cup of hot coffee. Optional whipped cream and a cinnamon stick can be added.

Cafe L'Orange is prepared with 1/2 ounce cognac, 1/2 ounce Cointreau, 1 ounce Mandarine Napoleon, and 4 ounces of hot coffee. The rim of the coffee cup should be dipped in lime juice and sugar. Boston Caribbean Coffee is made with 1 ounce Creme de Cacao (brown), 1 ounce dark rum, and hot coffee, sprinkled with ground cinnamon and with a cinnamon stick. A cinnamon stick may also be added for additional flavoring.

It is topped with whipped cream and sprinkled with chocolate shavings. Black Gold is made with 4 ounces of hot coffee, 1/4 ounce triple sec, Amaretto, Irish Cream liqueur, hazelnut liqueur, and a dash of cinnamon schnapps. It consists of coffee, ice, and sweetened condensed milk. Thai iced coffee is a popular drink commonly offered at Thai restaurants in the United States.

A frappuccino is an iced latte, mocha, or macchiato mixed with crushed ice and flavorings (such as vanilla/hazelnut if requested by the customer) and blended. Another prominent example is the Javakula at Seattle's Best Coffee. One commonly used by many stores is Ice Storm. Other coffeehouses serve similar concoctions, but under different names, since "Frappuccino" is a Starbucks trademark.

Frappuccino is a variation of iced coffee created by Starbucks. Frappé is served cold, with a drinking straw, either with or without sugar or milk. This type of coffee is probably consumed in Greece more than traditional Greek coffee, especially in the spring and summer months. It was created in Greece in 1957 in the city of Thessaloniki.

Frappé is a cold coffee drink made from instant coffee. Iced coffee can also be an iced form of any drink in this list. Since sugar does not dissolve well in cold coffee, it is conventionally added while the coffee is hot. Iced coffee normally contains milk and sugar.

Chicory has historically been used as a coffee substitute when real coffee was scarce, as in wartime. Chicory is sometimes combined with coffee as a flavoring and mellowing agent, as in the style of coffee served at the famous Café du Monde in New Orleans. It is popular on the islands of Java and Bali and their surroundings. However, kopi tubruk is made from coarse coffee grounds, and is boiled together with a solid lump of sugar.

Kopi tubruk is an Indonesian-style coffee similar in presentation to Greek coffee. In many places it is customary to serve it with a tall glass of water on the side. (See above for preparation method.) It is usually made sweet, with sugar added before the brew process begins, and often is flavored with cardamom or other spices. The crema or "face" is considered crucial, and since it requires some skill to achieve its presence is taken as evidence of a well-made brew.

Traditional Turkish coffee cups have no handles, but modern ones often do. Turkish coffee, also called Greek coffee or Armenian coffee (Surj), is served in very small cups about the size of those used for espresso. It is also highly popular in Cambodia and Laos. Due to the high volume of coffee grounds required to make strong coffee in this fashion, the brewing process is quite slow.

In this form, hot water is allowed to drip though a metal mesh into a cup, and the resulting strong brew is poured into a glass containing sweetened condensed milk which may contain ice. Vietnamese-style coffee is another form of drip brew. The ratio is usually 1/4 decoction, 3/4 milk. The coffee is drip-brewed for a few hours in a traditional metal coffee filter before being served with milk and sugar.

Indian (Madras) filter coffee, particularly common in southern India, is prepared with rough-ground dark roasted coffee beans (e.g., Arabica, PeaBerry). Common flavors are caramel and vanilla, but others are sometimes used. As with the latte and the caffe macchiato, sugar or syrup can be added to a latte macchiato. Latte macchiato is the inverse of a caffè macchiato, being a tall glass of steamed milk spotted with a small amount of espresso.

The most commonly used flavors are caramel and vanilla, but others can be added as well. As with latte, sometimes sugar or flavored syrup will be added to a macchiato. Caffè macchiato — macchiato meaning "marked" or "spotted" — is an espresso with a small amount of steamed milk added to the top, usually 1-2 oz. Mocha is a latte with chocolate added.

In the Maghreb, the orange blossom is used as a flavoring. Other flavorings include spices such as cinnamon, nutmeg, cardamom, or Italian syrups. Chocolate is a common additive that is either sprinkled on top or mixed with the coffee to imitate the taste of Mocha. Flavored coffee: In some cultures, flavored coffees are common.

Long black is espresso, usually a double shot, with equal parts hot water, favored in New Zealand and Australia. Americano style coffee is made with espresso (normally several shots) and hot water to give a similar strength (but different flavor) from drip-brewed coffee. Some add sugar. Café au lait is similar to latte except that drip-brewed coffee is used instead of espresso, with an equal amount of milk.

Common flavors are caramel and vanilla, yet other flavors are often added as well. Often sugar or flavored syrup will be added to a latte. A latte is also commonly served in a tall glass; if the espresso is slowly poured into the frothed milk from the rim of the glass, three layers of different shades will form, with the milk at the bottom, the froth on top and the espresso in between. More frothed milk makes it weaker than a cappuccino, and a traditional latte is served an average 10–20 degrees Celsius cooler than a black or white coffee or cappuccino.

A latte comprises one-third espresso and nearly two-thirds steamed milk. Latte (as it is known in the USA, Italian for "milk" - originally caffè e latte or café latte) is espresso with steamed milk, traditionally topped with froth created from steaming the milk. This is a specialty of Australia and New Zealand, particularly favored in the latter. Flat white is a shot of espresso in a cappuccino cup, topped up with steamed milk but no foam.

Cappuccino comprises equal parts espresso, steamed milk, and milk froth, and is occasionally garnished with spices or powdered cocoa. (Note: though having a similar term, this is not to be confused with the Beirut herbal tea or Ipoh town coffee blend). Some add sugar. White coffee is black coffee with milk added.

A demitasse is somewhat similar to an espresso without the crema: a small cup of strong black coffee often served after a meal. Some add sugar. Black coffee is drip-brewed, percolated, vacuum brewed, or French-press-style coffee served without cream. This method is especially suitable for use with local-brew coffees in Malaysia, primarily of the varieties Robusta and Liberica which are often much stronger in flavor, allowing the ground coffee in the sock to be reused.

Malaysian coffee is often brewed using a "sock", which is really just a muslin bag shaped like a filter into which coffee is loaded then steeped into hot water. Coffee bags (akin to tea bags) are much rarer than their tea equivalents, as they are much bulkier (more coffee is required in a coffee bag than tea in a tea bag). This style of "total immersion brewing" is considered by many coffee experts to be the ideal way to prepare fine coffee at home. The coffee and hot water are combined in the cylinder (normally for four minutes) before the plunger, in the form of a metal foil, is depressed, leaving the coffee at the top ready to be poured.

A cafetière (or French press) is a tall, narrow glass cylinder with a plunger that includes a filter. Steeping: