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Coffee is a beverage, usually served hot, prepared from the roasted seeds of the coffee plant. These seeds are usually called coffee beans. Coffee is the second most traded commodity in the world, trailing only petroleum. Coffee is one of humanity's chief sources of caffeine, a stimulant. Its potential benefits and hazards have been, and continue to be, widely studied and discussed.
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The word entered English in 1598 via Italian caffè, via Turkish kahveh, from Arabic qahwa. Its ultimate origin is uncertain, there being several legendary accounts of the origin of the drink. One possible origin is the Kaffa region in Ethiopia, where the plant originated (its native name there being bunna). Coffee beans were first imported from Ethiopia to Yemen. One legendary account (though certainly a myth) is that of the Yemenite Sufi mystic named Shaikh ash-Shadhili. 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. A similar myth ascribes the discovery to an Ethiopian goatherd named Kaldi. Qahwa originally referred to a type of wine, and need not be the name of the Kaffa region.
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was outlawed in Mecca in 1511 and in Cairo in 1532, but in the face of its immense popularity, the decree was later rescinded. In 1554, the first coffeehouse in Istanbul opened. Coffee was introduced in England in the 1430s by the Greek professor in Oxford Ioannis Servopoulos. 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. By 1675, there were more than 3,000 coffeehouses in England. Women were not allowed in coffeehouses, and in London, the anonymous 1674 "Women's Petition Against Coffee" complained that
the Excessive Use of that Newfangled, Abominable, Heathenish Liquor called COFFEE [...] has [...] Eunucht our Husbands, and Crippled our more kind Gallants, that they are become as Impotent, as Age [1].
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. 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. 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. 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 mother plant for much of the arabica coffee in the world is kept in the Amsterdam Hortus Botanicus.
In English, "cafe" refers mostly to places where meals are served, as well as coffee. In Dutch the word refers to a bar and is thus more associated with alcohol consumption. 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). This usage of the word has also spread to other languages.
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. There is also often a selection of desserts or light sandwiches and other snacks.
There are two main species of the coffee plant. Coffea arabica is the older of them. It is thought to be indigenous to Ethiopia, but as the name implies it was first cultivated on the Arabian Peninsula. 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. 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. Compared to arabica, robusta tends to be more bitter, with a telltale "burnt rubber" aroma and flavor. Good quality robustas are used as ingredients in some espresso blends to provide a better "crema" (foamy head), and to lower the ingredient cost. In Italy many espresso blends are based on dark-roasted robusta.
Arabica coffees were traditionally named by the port they were exported from, the two oldest being Mocha, from Yemen, and Java, from Indonesia. The modern coffee trade is much more specific about origin, labeling coffees by country, region, and sometimes even the producing estate. Coffee aficionados may even distinguish auctioned coffees by lot number.
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 pressure and financing provided by the World Bank indirectly through the French Government. Many experts believe this giant influx of cheap green coffee led to the prolonged pricing crisis from 2001 to the present. 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. 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.
One unusual and very expensive variety of robusta is the Indonesian Kopi Luwak and the Philippine Kape Alamid. The beans are collected from the droppings of the Common Palm Civet, whose digestive processes give it a distinctive flavor.
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, and acidity. These are dependent on the local environment where the coffee plants are grown, their method of process, and the genetic subspecies or varietal.
Some well-known arabica coffees include:
Coffees are often blended for balance and complexity, and many popular blendings exist. One of the oldest traditional blends is Mocha-Java, combining beans of the same name. 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. Nowadays, the Mocha-Java blend is often blended with some other varieties to provide variety. In addition to those blends sold commercially, many coffee houses have their own signature "house blends".
Some bean varieties are so well-known and so in-demand that they are far more expensive than others. Jamaican Blue Mountain and Hawaiian Kona coffees are perhaps the most prominent examples. Often these beans are blended with other, less expensive varieties and the blend labeled as "Blue Mountain blend" or "Kona blend" even though they only contain a small amount of the coffee mentioned.
A number of classifications are used to label coffee produced under certain environmental or labor standards. So-called Ethical coffee is produced or traded under specific conditions and guidelines, which are claimed to be more environmentally friendly or economically equitable to the producers.
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.
Coffee berries are most commonly picked by hand by labourers who receive payment by the basketful. As of 2003, payment per basket is between US$2.00 to $0.10 with the overwhelming majority of the labourers receiving payment at the lower end. An experienced coffee picker can collect up to 6-7 baskets a day. 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. This discernment typically only occurs with growers who harvest for higher end/specialty coffee where the pickers are paid better for their labour.
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. Red berries, with its higher aromatic oil and lower organic acid content are more fragrant, smooth, and mellow. 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.
The coffee berries are a type of drupe, with fruit flesh directly covering the coffee bean. For "washed" coffees, after harvesting, the flesh of the coffee berry must be quickly removed by soaking, scouring and/or mechanical rubbing. The defruited coffee bean is flushed with water to remove clinging fruit and additional sugars before drying. These coffees tend to rest in water (the "ferment" stage) for a set amount of time (depending on the origin and producer). 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. This creates a unique flavour profile with reduced acidity and increased body, though if done poorly can lead to defect. Other coffee processing methods include the Pulped Natural process, the Indonesian "semi-washed" methods as well as aguapulping and re-fermentation. Each produces its own flavour profile and each is, in essence, a different way of handling the process of defruiting the beans.
Coffee beans are spread over a large concrete or rock surface where they are dried by air and sunlight. The beans are repeatedly raked into rows and spread out over the course of several days until they are largely dry. At this stage, the beans are referred to as "green coffee".
The first step in preparation is sorting of beans by color and size. Discoloured, rotten, and damaged beans are also removed at this point. In many less developed countries, hand sorting is still done because of the low cost of labor. Elsewhere, beans are sorted automatically by sophisticated machines that employ CCD cameras and can determine both size and color. Automatic sorting is cost-effective for large producers where quantity and throughput are important factors in production.
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. 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.
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.
The roasting process is integral to producing a savory cup of coffee. When roasted, the green coffee bean expands to nearly double its original size, changing in color and density. As the bean absorbs heat, the color shifts to yellow and then to a light "cinnamon" brown. During this stage the moisture in the beans is expelled. 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. This oil contains the distinctive compounds which give coffee its flavor; the more oil released, the stronger the flavor. Coffee beans will crack during the roasting process, not unlike popping popcorn. "First crack" and "second crack" are benchmarks that a roaster will use to gauge how the roast progresses. 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.
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. Coffee beans from famous regions like Java and Kenya are usually roasted lightly so their signature characteristics dominate the flavor. 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.
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. 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. These roasts are sold by the degree of roast, ranging from "Vienna Roast" to "French Roast" and beyond. The dividing line between extremely dark roast and "burnt" is a matter of some debate. Contrary to popular belief, the darker roasts and more strongly flavored coffees do not deliver any more caffeine than lighter roasts. 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.
In the 19th century coffee was usually bought in the form of green beans and roasted in a frying pan. This form of roasting requires much skill to do well, and fell out of favor when vacuum sealing of pre-roasted coffee became possible. Today home roasting is becoming popular again. Computerized drum roasters are available which simplify home roasting, and some home roasters will simply roast in an oven or in air popcorn makers.
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. 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. 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.
Once roasted, the volatile compounds that give coffee its complex flavors dissipate quickly. 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. 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. However, as is said in the coffee industry, "the proof is in the cup."
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. Brewing methods which expose coffee grounds to heated water for a longer duration of time require a coarser grind than faster brewing methods. 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. At the other extreme, an overly coarse grind will produce a weak, watery, under-flavored result.
The rate of deterioration increases when the coffee is ground, as a result of the greater surface area exposed to oxygen. 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.
There are two methods of producing coffee grounds ready for brewing.
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. 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.
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. The fineness of the grind required differs by the method of extraction.
Water temperature is crucial to the proper extraction of flavor from the ground coffee. The recommended brewing temperature of coffee is 93 °C (204 °F). Any cooler and some of the solubles that make up the flavor will not be extracted. If the water is too hot, some undesirable elements will be extracted, adversely affecting the taste, especially in bitterness.
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 of water; the full two tablespoons per six ounces tends to be recommended by experienced coffee lovers.
Brewed coffee continually heated will deteriorate rapidly in flavor; even at room temperature, deterioration will occur. For this reason aficionados frown upon the hotplate which is sometimes used to keep brewed coffee warm prior to serving. 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.
Electronic coffee makers boil the water and brew the infusion with little human assistance and sometimes according to a timer. Some even grind the beans automatically before brewing. Connoisseurs shun such conveniences as compromising the flavor of the coffee; they prefer freshly ground beans and traditional brewing techniques.
Instant and soluble coffee has been dried into soluble powder or granules, which can be quickly dissolved in hot water for consumption.
Canned coffee is a beverage that has been popular in Asian countries for many years, particularly in Japan and South Korea. Vending machines typically sell a number of varieties of canned coffee, available both hot and cold. To match with the often busy life of Korean city dwellers, companies mostly have canned coffee with a wide variety of tastes. 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. 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). They also sell a canned espresso drink, Double Shot, lightly sweetened and blended with cream. Other premade coffee drinks are also commercially available, but tend to be less popular.
Another type of premade coffee is liquid coffee concentrate. It is described as having a flavor about as good as low-grade robusta coffee. It costs about 10 cents a cup to produce. Its primary use is in large institutional situations where coffee needs to be produced for thousands of people at the same time. The machines used to process it can handle up to 500 cups an hour, or 1,000 if the water is preheated.[3]
See also: Coffeehouse for a social history of coffee, and caffé for specifically Italian traditions.
The United States is the largest market for coffee, followed by Germany. Finland consumes the most coffee per capita, an average of four to five cups a day. However, consumption has also vastly increased in the United Kingdom in recent years. Coffee is so popular in the Americas, the Middle East, and Europe that many restaurants specialize in coffee; these are called "coffeehouses" or "cafés". Most cafés also serve tea, sandwiches, pastries, and other light refreshments. Some cafés are miniature shacks that specialize in coffee-to-go for hurried travelers, who may visit these on their way to work as a substitute for breakfast. Some travelers transport their coffee in vacuum bottles, which can keep a beverage hot for hours.
In some countries, notably in northern Europe, coffee parties are a popular form of entertaining. Besides coffee, the host or hostess at the coffee party also serves cake and pastries, hopefully homemade.
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. Social habits involving coffee in offices include the morning chat over coffee and the coffee break. In recent years, contemporary advertising has shifted the sum of "breaks" plus coffee into a meaning, or function, of rest and relaxation. This is ironic in that, as stated earlier, coffee is a stimulant.
In recent years, cafés have begun to offer wireless Internet (Wi-Fi) connectivity to attract customers. 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.
See also dunk (biscuit) for the habit of dipping a biscuit (cookie) or cake into a coffee.
Coffee is one of the world's most important primary commodities; it ranks second only to petroleum in terms of dollars traded worldwide. With over 400 billion cups consumed every year, coffee is the world's most popular beverage. Worldwide, 25 million small producers rely on coffee for a living. 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. The collapse of price support schemes in the 1980s and the entry of new producing countries (notably Vietnam) has led to world prices for raw coffee beans fluctuating wildly, reaching an all-time low (in constant dollars) in 2002.[4]
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. 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.
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.
Coffee contains caffeine, which acts as a stimulant. For this reason, it is often consumed in the morning, and during working hours. Students preparing for examinations with late-night "cram sessions" use coffee to maintain their concentration. Many office workers take a "coffee break" when their energy is diminished.
Recent research has uncovered additional stimulating effects of coffee which are not related to its caffeine content. Coffee contains an as yet unknown chemical agent which stimulates the production of cortisone and adrenaline, two stimulating hormones.
For occasions when one wants to enjoy the flavor of coffee with less stimulation, decaffeinated coffee (also called decaf) is available. 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. Another solvent used is ethyl acetate; the resultant decaffeinated coffee is marketed as "natural decaf" due to ethyl acetate being naturally present in fruit. Extraction with supercritical carbon dioxide has also been employed.
Decaffeinated coffee usually loses some flavor over normal coffees and tends to be more bitter. There are also tisanes that resemble coffee in taste but contain no caffeine (see below).
Caffeine dependence is widespread and withdrawal symptoms are real. See the caffeine article for more on the pharmacological effects of caffeine.
Coffee increases the effectiveness of pain killers—especially migraine medications—and can rid some people of asthma. 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. Coffee intake may reduce one's risk of diabetes mellitus type 2 by up to half. 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).
Coffee can also reduce the incidence of cirrhosis of the liver and prevent colon and bladder cancers. Coffee can reduce the risk of hepatocellular carcinoma, a variety of liver cancer (Inoue, 2005). 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. 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.[5]
Coffee contains the anticancer compound methylpyridinium. This compound is not present in significant amounts in other food materials. Methylpyridinium is not present in raw coffee beans but is formed during the roasting process from trigonellin, which is common in raw coffee beans. It is present in both caffeinated and decaffeinated coffee, and even in instant coffee. 6
Coffee is also a powerful stimulant for peristalsis and is sometimes considered to prevent constipation; it is also a diuretic.
Many people drink coffee for its ability to increase short term recall and increase IQ. 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 these health effects are realized by as little as 4 cups a day (24 U.S. fl oz, 700 mL), but others occur at 5 or more cups a day (32 U.S. fl oz or 0.95 L or more).
Some controversy over these effects exists, since by its nature coffee consumption is associated with other behavioral variables. 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.
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.
Many notable effects of coffee are related to its caffeine content.
Many coffee drinkers are familiar with "coffee jitters", a nervous condition that occurs when one has had too much caffeine. 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. Coffee can also cause insomnia in some, while paradoxically it helps a few sleep more soundly. It can also cause anxiety and irritability, in some with excessive coffee consumption, and some as a withdrawal symptom. 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. fl oz or 1.4 L or more).
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). "The results seem to indicate a threshold effect around four to seven cups per day," the study reported. Those who drank eight or more cups a day (48 U.S. fl oz or 1.4 L) were at 220% increased risk compared with nondrinkers. This study has not yet been repeated, but has caused some doctors to caution against excessive coffee consumption during pregnancy.
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. 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. 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. 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.
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. The study concluded that consumption of coffee is associated with significant elevations in biochemical markers of inflammation. 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.
The health risks of decaffeinated coffee have been studied, with varying results. 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.
A study has shown that cafestol, a substance which is present in boiled coffee drinks, dramatically increases cholesterol levels, especially in women. Filtered coffee only contains trace amounts of cafestol.
Spent coffee grounds are a good fertilizer in gardens because of their high nitrogen content. Coffee grounds also contain potassium, phosphorus, and many other trace elements that aid plant development. Many gardeners report that roses love coffee grounds and when furnished with the same become big and colorful. When added to a compost pile, spent coffee grounds compost very rapidly.
Coffee grounds can be obtained inexpensively (usually fre