A coffee bean is a seed from the Coffea plant and the source for coffee . It is the pit inside the red or purple fruit. This fruit is often referred to as a coffee cherry , and like the cherry, it is a fruit with a pit. Even though the coffee beans are not technically beans, they are referred to as such because of their resemblance to true beans . The fruits most commonly contain two stones with their flat sides together. A small percentage of cherries contain a single seed, called a " peaberry ". Peaberries make up only around 10% to 15% of all coffee beans. It is a fairly common belief that they have more flavour than normal coffee beans. Like Brazil nuts (a seed) and white rice, coffee beans consist mostly of endosperm .
94-422: Coffee preparation is the process of turning coffee beans into liquid coffee . While the particular steps vary with the type of coffee and with the raw materials, the process includes four basic steps: raw coffee beans must be roasted , the roasted coffee beans must then be ground , and the ground coffee must then be mixed with hot or cold water (depending on the method of brewing) for a specific time ( brewed ),
188-439: A blade grinder designed specifically for coffee and spices, or in a general use home blender . Devices of this sort are cheaper than burr grinders, but the grind is not uniform and will produce particles of widely varying sizes, while ideally all particles should have the same size, appropriate for the method of brewing. Moreover, the particles get smaller and smaller during the grinding process, which makes it difficult to achieve
282-452: A life cycle approach to sustainability , this large quantity of waste requires waste management plans. Due to the amount of spent coffee grounds generated and the chemical properties of spent coffee grounds, the usage of spent coffee grounds is avidly investigated. It is not recommended to burn dried used coffee grounds, as they give off hazardous nitrogen oxides when burnt. In gardens, coffee grounds may be used for composting or as
376-410: A mulch as they are known to slowly release nitrogen into the soil. They are said to be especially appreciated by worms and acid-loving plants , such as blueberries , although due to acids being leached from the grounds while in use, they typically have a neutral pH, and red wiggler growth and survival has been experimentally tested and found to be reduced in treatments using used coffee grounds as
470-399: A substrate for the cultivation of mushrooms (including oyster mushrooms ). The use of spent coffee grounds in this application has the advantage of the used coffee grounds needing no pre-treatment to be usable as a mushroom substrate. Application of 10 kg used coffee grounds per square metre has been suggested as part of a crop rotation system, where for the first six months, the field
564-420: A bitter taste in water, which is masked by organic acids present in green coffee. Trigonelline ( N -methyl-nicotinate) is a derivative of vitamin B 3 that is not as bitter as caffeine. In green coffee beans, the content is between 0.6% and 1.0%. At a roasting temperature of 230 °C (446 °F), 85% of the trigonelline is degraded to nicotinic acid , leaving small amounts of the unchanged molecule in
658-425: A coffee pod composed of finely ground coffee sealed between two layers of filter paper or through a proprietary capsule containing ground coffee. Examples include the pod-based Senseo and Home Café systems and the proprietary Tassimo and Keurig K-Cup systems. The AeroPress is another recent invention, which is a mechanical, non-electronic device where pressure is simply exerted by the user manually pressing
752-423: A consistent grind from batch to batch. Blade grinders create "coffee dust" that can clog up sieves in espresso machines and French presses, and are best suited for drip coffee makers. They are not recommended for grinding coffee for use with pump espresso machines. Arabic coffee and Turkish coffee require that the grounds be almost powdery in fineness, finer than can be achieved by most burr grinders. Pounding
846-580: A defined area between the tropics of Cancer and Capricorn , termed the bean belt or coffee belt. The Oxford English Dictionary suggests that the European languages generally appear to have adopted the name from Turkish kahveh , about 1600, perhaps through Italian caffè . Arab qahwah , in Turkish pronounced kahveh , the name of the infusion or beverage ; said by Arab lexicographers to have originally meant " wine " or some type of wine, and to be
940-586: A derivative of a verb - root qahiya "to have no appetite ". Another common theory is that the name derives from Kaffa Province, Ethiopia , where the species may have originated. The coffee tree averages from 5–10 m (16–33 ft) in height. As the tree gets older, it produces less fruit and slowly loses any pest- and disease-resistance. The coffee beans come from the seeds which contained in fruits from trees and shrubs naturally grown in African forests. Humans produce coffee by roasting , grinding and brewing
1034-566: A further 20% is lignins . The dry coffee grounds contain significant amounts of potassium (11.7 g/kg), nitrogen (27.9 g/kg), magnesium (1.9 g/kg), and phosphorus (1.8 g/kg). The quantity of caffeine remaining in used coffee grounds is around 48% of that in fresh coffee grounds. There are significantly less tannins in used coffee grounds than fresh coffee grounds. On average, 1 tonne of green coffee produces approximately 650 kg of spent coffee grounds, and over 15 million tonnes of spent coffee grounds are generated annually. In keeping with
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#17328552406331128-476: A hot beverage. Even with the same roast, the character of the extraction is highly dependent on distribution of particle sizes produced by the grinding process, temperature of the grounds after grinding, freshness of the roast and grind, brewing process and equipment, temperature of the water, character of the water itself, contact time with hot water (less sensitive with cold water), and the brew ratio employed. Preferred brew ratios of water to coffee often fall into
1222-411: A layer of flavorful emulsified oils in the form of a colloidal foam floating on the surface, which is produced by the high pressure. Espresso is more viscous than other forms of brewed coffee. The moka pot , also known as the "Italian coffeepot" or the "caffettiera," is a three-chamber design which boils water in the lower section. The generated steam pressure, about one bar (100 kPa, 14.5 psi), forces
1316-433: A lightly packed matrix, called a "puck," of finely ground coffee. The 30–60 millilitres (1.1–2.1 imp fl oz) beverage is served in demitasse cups; sugar is often added. It is consumed during the day at cafes and from street vendors, or after an evening meal. It is the basis for many coffee drinks. It is one of the most concentrated forms of coffee regularly consumed, with a distinctive flavor provided by crema ,
1410-536: A limb all at once. Selective picking is often used to produce higher quality coffee because the cherries are picked at their ripest. Strip-picking is indiscriminate and will harvest unripe, ripe, and over-ripe fruit. To improve quality after strip-picking, the harvest must be sorted. Two methods are primarily used to process coffee berries. The first, "wet" or "washed" process, has historically usually been carried out in Central America and areas of Africa. The flesh of
1504-711: A lower amount in robustas, i.e. 4500 mg/100 g. In arabica green coffee beans, the content of free glucose was 30 to 38 mg/100 g, free fructose 23 to 30 mg/100 g; free galactose 35 mg/100 g and mannitol 50 mg/100 g dried coffee beans, respectively. Mannitol is a powerful scavenger for hydroxyl radicals , which are generated during the peroxidation of lipids in biological membranes. The lipids found in green coffee include: linoleic acid , palmitic acid , oleic acid , stearic acid , arachidic acid , diterpenes , triglycerides , unsaturated long-chain fatty acids , esters , and amides . The total content of lipids in dried green coffee
1598-416: A molecular weight of 90 kDa to 200 kDa. It is composed of beta-1-3-linked galactan main chains, with frequent members of arabinose (pentose) and galactose (hexose) residues at the side chains comprising immunomodulating properties by stimulating the cellular defense system (Th-1 response) of the body. Mature brown to yellow coffee beans contain fewer residues of galactose and arabinose at the side chain of
1692-617: A more even extraction when brewed, without excessively fine particles that clog filters. These mills offer a wide range of grind settings, making them suitable to grind coffee for various brewing systems such as espresso, drip, percolators, French press, and others. Many burr grinders, including almost all domestic versions, are unable to achieve the extremely fine grind required for the preparation of Turkish coffee ; traditional Turkish hand grinders are an exception. Burr grinders are of two types - conical burrs and flat wheel burrs. Most manual coffee grinders use conical burrs, but there have been
1786-408: A number of exceptions recently using flat wheel burrs including ghost burrs and hybrid designs. Both of them grind coffee bean consistently and with uniform size. There are also burr grinders, including a few manual coffee grinders, utilizing two burr sets for prebreaking and fine-grinding in order to sieve out coffee chaff , potentially work as slow feeders, achieve more uniform coffee grinds, and, in
1880-419: A piston down with their hand, forcing medium-temperature water through coffee grounds in about 30 seconds (into a single cup.) This method produces a smoother beverage than espresso, falling somewhere between the flavor of a moka pot and a French Press . Proper brewing of coffee requires using the correct amount of coffee grounds, extracted to the correct degree (largely determined by the correct time), at
1974-442: A pleasant taste. A steeping time of 12 minutes or under provides a more palatable liquid that can be used as a base for a drink containing more of the nutrients and less caffeine that using just isolated caffeine extract. The alkaline stock base that results can be paired with acidic or fruity extracts, with or without sweetener, to mask the vegetable-like taste of the extract. When green coffee beans are roasted, other molecules with
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#17328552406332068-419: A pot with an orange handle). A variation is the traditional Neapolitan flip coffee pot , or Napoletana, a drip brew coffee maker for the stovetop. It consists of a bottom section filled with water, a middle filter section, and an upside-down pot placed on the top. When the water boils, the coffee maker is flipped over to let the water filter through the coffee grounds. The common electric percolator , which
2162-513: A very early method of making coffee, is used in the Middle East , North Africa , East Africa , Turkey , Greece , the Balkans , and Russia . Very finely ground coffee, optionally sugar, and water are placed in a narrow-topped pot, called a cezve ( Turkish ), kanaka ( Egyptian ), briki ( Greek ), džezva ( Štokavian ) or turka ( Russian ) and brought to the boil then immediately removed from
2256-400: Is 11.7–14 g/100 g. Lipids are present on the surface and in the interior matrix of green coffee beans. On the surface, they include derivatives of carboxylic acid-5-hydroxytryptamides with an amide bond to fatty acids (unsaturated C6 to C24) making up to 3% of total lipid content or 1200 to 1400 microgram/g dried green coffee bean. Such compounds form a wax-like cover on the surface of
2350-557: Is 65 mg/g and of robusta 140 mg/g, depending on the timing of harvesting. At roasting temperature, more than 70% of chlorogenic acids are destroyed, leaving a residue less than 30 mg/g in the roasted coffee bean. In contrast to green coffee, green tea contains an average of 85 mg/g polyphenols. These chlorogenic acids could be a valuable, inexpensive source of antioxidants. Chlorogenic acids are homologous compounds comprising caffeic acid , ferulic acid and 3,4-dimethoxycinnamic acid , which are connected by an ester bond to
2444-456: Is Brazil. Other main exporters of coffee beans are Colombia, Vietnam and Ethiopia. Brazil produces about 45% of the world's total coffee exports . The United States imports more coffee than any other nation. As of 2015, Americans consumed approximately 400 million cups of coffee per day, making the United States the leading consumer of coffee in the world. Coffee plants grow within
2538-469: Is a special pan or apparatus suitable to heat up and roast green coffee beans. The whole coffee beans are ground, also known as milling , to facilitate the brewing process. The fineness of the grind strongly affects brewing. Brewing methods that expose coffee grounds to heated water for longer require a coarser grind than faster brewing methods. Beans that are too finely ground for the brewing method in which they are used will expose too much surface area to
2632-540: Is about 20% of the lipid fraction. The diterpenes found in green coffee include cafestol , kahweol and 16-O-methylcafestol . Some of these diterpenes have been shown in in vitro experiments to protect liver tissue against chemical oxidation. In coffee oil from green coffee beans the diterpenes are esterified with saturated long chain fatty acids . Chlorogenic acids belong to a group of compounds known as phenolic acids , which are antioxidants . The content of chlorogenic acids in dried green coffee beans of arabica
2726-400: Is accelerated in the presence of organic acids such as chlorogenic acids and their derivatives. Other proteins include enzymes , such as catalase and polyphenol oxidase , which are important for the maturation of green coffee beans. Mature coffee contains free amino acids (4.0 mg amino acid/g robusta coffee and up to 4.5 mg amino acid/g arabica coffee). In Coffea arabica , alanine
2820-453: Is allowed to lie fallow with a layer of coffee grounds on it suppressing weed growth, then the coffee grounds are plowed in and legumes are grown, which fix their own nitrogen. Application of an equal amount of horse manure at the same time as the coffee grounds has been shown to nearly eliminate negative effects of fresh used coffee grounds. It has been proposed to use spent coffee grounds to feed ruminants, pigs, chickens and rabbits, but
2914-469: Is done. Even at room temperature, deterioration will occur; however, if 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, with refrigerated bottled coffee drinks being commonly available at convenience stores and grocery stores in the United States. Canned coffee
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3008-538: Is fed a single-serving " pod " of pre-measured coffee grounds for each beverage. Characteristics which may be emphasized or deemphasized by different preparation methods include: acidity (brightness), aroma (especially more delicate floral and citrus notes), mouthfeel (body), astringency , bitterness (both positive and negative), and the duration and intensity of flavour perception in the mouth (finish). The addition of sweeteners, dairy products (e.g. milk or cream), or dairy alternatives (e.g. almond milk ) also changes
3102-443: Is made by heating coarse grounds with water in a pot, letting the grounds settle and pouring off the liquid to drink, sometimes filtering it to remove fine grounds. While the name suggests that this method was used by cowboys, presumably on the trail around a campfire, it is used by others; some people prefer this method. The above methods are sometimes used with hot milk instead of water. Turkish coffee (aka Arabic coffee, etc.),
3196-401: Is needed at the beginning of the season when the fruit is developing and less later in the season as it ripens. Two lesser known species grown for consumption are Coffea liberica and Coffea racemosa . When the fruit is ripe, it is almost always handpicked, using either "selective picking", where only the ripe fruit is removed, or "strip-picking", where all of the fruit is removed from
3290-474: Is often sealed into a vacuum flask or insulated bottle to maintain its temperature. In most areas, coffee may be purchased unprocessed, or already roasted, or already roasted and ground. Whole roast coffee or ground coffee is often vacuum-packed to prevent oxidation and lengthen its shelf life. Especially in hot climates, some find cold or iced coffee more refreshing. This can be prepared well in advance as it maintains its character when stored cold better than as
3384-411: Is one of the world's most widely consumed beverages, coffee beans are a major cash crop and an important export product, accounting for over 50% of some developing nations' foreign exchange earnings. In 2017, 70% of total coffee production was exported, worth US$ 19.9 billion. The global coffee industry is massive and valued at $ 495.50 billion as of 2023, the biggest producer of coffee and coffee beans
3478-461: Is particularly popular in Japan and South Korea. Electronic coffee makers boil the water and brew the infusion with little human assistance and sometimes according to a timer. Some such devices also grind the beans automatically before brewing. The French press is considered one of the oldest and simplest methods to brew coffee. Despite its simplicity, it can be a little tricky. The most important part of
3572-508: Is perceptible at around 20 mg/liter of water. The content of diketopiperazines in espresso is about 20 to 30 mg, which is responsible for its bitterness . Carbohydrates make up about 50% of the dry weight of green coffee beans. The carbohydrate fraction of green coffee is dominated by polysaccharides , such as arabinogalactan , galactomannan , and cellulose , contributing to the tasteless flavor of green coffee. Arabinogalactan makes up to 17% of dry weight of green coffee beans, with
3666-611: Is reduced during the roasting process, usually about 15 minutes at 230 °C (446 °F), whereas the concentrations of most other alkaloids are not changed. The solubility of caffeine in water increases with temperature and with the addition of chlorogenic acids, citric acid , or tartaric acid , all of which are present in green coffee beans. For example, 1 g (0.035 oz) of caffeine dissolves in 46 mL (1.6 US fl oz) of water at room temperature, and 5.5 mL (0.19 US fl oz) at 80 °C (176 °F). The xanthine alkaloids are odorless, but have
3760-512: Is the alkaloid most present in green and roasted coffee beans. The content of caffeine is between 1.0% and 2.5% by weight of dry green coffee beans. The content of caffeine does not change during maturation of green coffee beans, but higher caffeine content is found in plants grown at higher altitudes. Lower concentrations of theophylline , theobromine , paraxanthine , liberine , and methylliberine can be found. The concentration of theophylline, an alkaloid noted for its presence in green tea ,
3854-841: Is the amino acid with the highest concentration, i.e. 1.2 mg/g, followed by asparagine of 0.66 mg/g, whereas in C. robusta , alanine is present at a concentration of 0.8 mg/g and asparagine at 0.36 mg/g. The free hydrophobic amino acids in fresh green coffee beans contribute to the unpleasant taste, making it impossible to prepare a desirable beverage with such compounds. In fresh green coffee from Peru, these concentrations have been determined as: isoleucine 81 mg/kg, leucine 100 mg/kg, valine 93 mg/kg, tyrosine 81 mg/kg, phenylalanine 133 mg/kg. The concentration of gamma-aminobutyric acid (a neurotransmitter) has been determined between 143 mg/kg and 703 mg/kg in green coffee beans from Tanzania . Roasted coffee beans do not contain any free amino acids;
Coffee preparation - Misplaced Pages Continue
3948-417: Is the pierced pressing disc with a stem handle, and a covering lid. The finely ground coffee with 15–20% chicory is placed in the upper compartment, the pierced pressing disc is used to cover the ground coffee, and hot water is poured on top of this disk. Unlike the regular drip brew, the coffee does not start pouring down immediately. This is because of the chicory, which holds on to the water longer than just
4042-481: Is the result of brewing coffee, and are the final product after preparation of coffee . Despite having several highly-desirable chemical components, used coffee grounds are generally regarded as waste, and they are usually thrown away or composted . As of 2019, it was estimated that over 15 million tonnes of spent coffee grounds are generated annually. Due to this quantity of waste and the chemical properties of used coffee grounds, they have several potential uses. In
4136-429: Is then filtered, usually through a very thick filter, removing all particles. This process produces a very strong concentrate which can be stored in a refrigerated, airtight container for up to eight weeks. The coffee can then be prepared for drinking by adding hot water to the concentrate at a water-to-concentrate ratio of approximately 3:1, but can be adjusted to the drinker's preference. The coffee prepared by this method
4230-515: Is to put the ground coffee in a cup, pour hot water over it and let cool while the grounds sink to the bottom. This is a traditional method for making a cup of coffee that is still used in parts of Indonesia . This method, known as "mud coffee" in the Middle East owing to an extremely fine grind that results in a mud-like sludge at the bottom of the cup, allows for extremely simple preparation, but drinkers then have to be careful if they want to avoid drinking grounds either from this layer or floating at
4324-430: Is very low in acidity with a smooth taste, and is often preferred by those with sensitive stomachs. Others, however, feel this method strips coffee of its bold flavor and character. Thus, this method is not common, and there are few appliances designed for it. The amount of coffee used affects both the strength and the flavor of the brew in a typical drip-brewing filtration-based coffee maker. The softer flavors come out of
4418-579: The Morena Kaffeefilter (c. 1960s–1970s) and the Onko Kaffee-Filter (c. 1960s–1970s) were devices combining steeping (immersion) with drip-filtering ( percolation ), a method sometimes also called percolative immersion , immersion pour-over , immersion drip brew , hybrid brewing , steeped bloom or steep & release . Newer devices supporting this include the Clever Dripper (2009),
4512-746: The hydroxyl groups of quinic acid . The antioxidant capacity of chlorogenic acid is more potent than of ascorbic acid (vitamin C) or mannitol, which is a selective hydroxy-radical scavenger. Chlorogenic acids have a bitter taste in low concentrations such as 50 mg/L water. At higher concentrations of 1 g/L water, they have a sour taste. Chlorogenic acids increase the solubility of caffeine and are important modulators of taste. Volatile compounds of green coffee beans include short-chain fatty acids, aldehydes , and nitrogen-containing aromatic molecules, such as derivatives of pyrazines (green-herbaceous-earthy odor). Briefly, such volatile compounds are responsible for
4606-880: The Bonavita Immersion Dripper (2014), the Goat Story GINA (2016), the December Dripper (2017), the Hario Switch (2019), the Melitta Amano (2020), the NextLevel Pulsar (2021), the Cuptimo (2022), and the Sworksdesign Bottomless Dripper (2023). Coffee bags are used less often than tea bags . They are simply disposable bags containing coffee; the grounds do not exit the bag as it mixes with
4700-468: The amino acids in green coffee beans are degraded under roasting temperature to Maillard products (reaction products between the aldehyde group of sugar and the alpha-amino group of the amino acids). Further, diketopiperazines , e.g. cyclo(proline-proline), cyclo(proline-leucine), and cyclo(proline-isoleucine), are generated from the corresponding amino acids, and are the major source of the bitter taste of roasted coffee. The bitter flavor of diketopiperazines
4794-402: The bean absorbs heat, its color shifts to yellow, then to a light "cinnamon" brown, and then to a rich dark brown color. During roasting, oils appear on the surface of the bean. The roast will continue to darken until it is removed from the heat source. Coffee can be roasted with ordinary kitchen equipment (frying pan, grill, oven, popcorn popper ) or by specialized appliances. A coffee roaster
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#17328552406334888-400: The beans releases the coffee's oils, which are then more easily extracted during the infusion process with hot water, making the coffee taste richer and smoother. Both manually and electrically powered mills are available. These mills grind the coffee to a fairly uniform size determined by the separation of the two abrasive surfaces between which the coffee is ground; the uniform grind produces
4982-645: The beans with a mortar and pestle can pulverise the coffee finely enough. In a roller grinder, the beans are ground between pairs of corrugated rollers. A roller grinder produces a more even grind size distribution and heats the ground coffee less than other grinding methods. However, due to their size and cost, roller grinders are used exclusively by commercial and industrial scale coffee producers. Water-cooled roller grinders are used for high production rates as well as for fine grinds such as Turkish and espresso. Coffee can be brewed in several different ways, but these methods fall into four main groups depending on how
5076-472: The berries and the fruit is then spread out in the sun on concrete, bricks or raised beds for 2–3 weeks, turned regularly for even drying. In Asia a third type of processing exists, where the Asian palm civet eats coffee berries and excretes the beans. Because the civet prefers the taste of the ripest cherries, the civet selectively harvests the cherries. Its digestive system then processes the beans by breaking down
5170-420: The boiling water up through coffee grounds held in the middle section, separated by a filter mesh from the top section. The resultant coffee (almost espresso strength, but without the crema) is collected in the top section. Moka pots usually sit directly on a stovetop heater or burner. Some models have a transparent glass or plastic top. Single-serving coffee machines force hot water under low pressure through
5264-427: The bowl, and the whole apparatus is set over a burner. As the water heats, it is forced by the increasing vapor pressure up the siphon and into the bowl where it mixes with the grounds. When all the water possible has been forced into the bowl the infusion is allowed to sit for some time before the brewer is removed from the heat. As the water vapor in the lower pot cools, it contracts, forming a partial vacuum and drawing
5358-411: The case of manual grinders, ease operation or improve through-put. Many electrical burr grinders offer larger hoppers for storing whole coffee beans and are easy to use with a portafilter for espresso grind. Almost every burr coffee grinder grinds with lower noise than with other grinding methods. Coffee beans can be chopped by using blades rotating at high speed (20,000 to 30,000 rpm ), either in
5452-521: The cherries is separated from the seeds and then the seeds are fermented – soaked in water for about two days. This softens the mucilage, which is a sticky pulp residue that is still attached to the seeds. Then this mucilage is washed off with water. The "dry processing" method, cheaper and simpler, was historically used for lower-quality beans in Brazil and much of Africa, but now brings a premium when done well. Twigs and other foreign objects are separated from
5546-585: The coffee bean (200–300 mg lipids/100 g dried green coffee bean) protecting the interior matrix against oxidation and insects. Further, such molecules have antioxidative activity due to their chemical structure. Lipids of the interior tissue are triglycerides, linoleic acid (46% of total free lipids), palmitic acid (30% to 35% of total free lipids), and esters. Arabica beans have a higher content of lipids (13.5–17.4 g lipids/100 g dried green coffee beans) than robustas (9.8–10.7 g lipids/100 g dried green coffee beans). The content of diterpenes
5640-604: The coffee beans, though a rather coarse grind is almost always called for. A plain glass cylinder may be used, or a vacuum flask arrangement to keep the coffee hot; this is not to be confused with a vacuum brewer—see below. The Arndt'sche Caffee-Aufgussmaschine (c. 1900), the Kaffeeaufgußkanne Max Thürmer (1900), the Büttner-Kaffeemaschine (1926), the Melitta 401 / 402 (1930s) filter holders,
5734-418: The coffee down through the filter. Drip brew coffee, also known as filtered coffee, is made by letting hot water drip onto coffee grounds held in a coffee filter surrounded by a filter holder or brew basket. Drip brew makers can be simple filter holder types manually filled with hot water, or they can use automated systems as found in the popular electric drip coffee-maker . Strength varies according to
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#17328552406335828-559: The coffee first and the more bitter flavors only after some time, so a large brew will tend to be both stronger and more bitter. This can be modified by stopping the filtration after a planned time and then adding hot water to the brew instead of waiting for all the water to pass through the grounds. In addition to the "cold press", there is a method called "Cold Drip Coffee". Also known as "Dutch Ice Coffee" (and very popular in Japan), instead of steeping, this method very slowly drips cold water into
5922-411: The coffee produced in low esteem because of this multiple-pass process. Others prefer gravity percolation and claim it delivers a richer cup of coffee in comparison to drip brewing. Indian filter coffee uses an apparatus typically made of stainless steel. There are two cylindrical compartments, one sitting on top of the other. The upper compartment has tiny holes (less than ~0.5 mm). And then there
6016-558: The correct temperature using the water of balanced mineral composition. SCAA defines a precise composition of water for the barista championships. Coffee bean The two most economically important varieties of coffee plants are the Arabica and the Robusta ; approximately 60% of the coffee produced worldwide is Arabica and ~40% is Robusta. Arabica beans consist of 0.8–1.4% caffeine and Robusta beans consist of 1.7–4.0% caffeine. As coffee
6110-403: The cylinder, and off-the-boil water is then poured into it. The coffee and hot water are left in the cylinder for a few minutes (typically 4–7 minutes) and then the plunger is gently pushed down, leaving the filter immediately above the grounds, allowing the coffee to be poured out while the filter retains the grounds. Depending on the type of filter, it is important to pay attention to the grind of
6204-524: The flavor of the coffee bean when it is roasted. Nonvolatile nitrogenous compounds (including alkaloids , trigonelline , proteins, and free amino acids ) and carbohydrates are of major importance in producing the full aroma of roasted coffee and for its biological action. Since the mid-2000s, green coffee extract has been sold as a nutritional supplement and has been clinically studied for its chlorogenic acid content and for its lipolytic and weight-loss properties. Caffeine (1,3,7-trimethylxanthine)
6298-434: The garden. These can also be used as biodiesel fuel. There are four methods of grinding coffee for brewing: burr-grinding , chopping , pounding , and roller grinding . Burr mills use two revolving abrasive elements, such as wheels or conical grinding elements made of stainless steel or ceramic, between which the coffee beans are crushed or "torn" with little frictional heating. The process of squeezing and crushing of
6392-593: The green coffee beans. Coffee plants are often grown in rows spaced apart depending on the desired density chosen by the farmer. Some farmers plant other trees, such as shade trees or other cash-crop trees, such as orange trees around them or plant the coffee on the sides of hills, because they need specific conditions to flourish. Ideally, Arabica coffee beans are grown at temperatures between 15 and 24 °C (59 and 75 °F) and Robusta between 24 and 30 °C (75 and 86 °F) and receive between 500 and 3,000 mm (20 and 118 in) of rainfall per year. More rain
6486-467: The ground coffee beans can. This causes the beverage to be much more potent than the American drip variety. 2–3 teaspoonfuls of this decoction is added to a 100–150 ml milk. Sugar is then sometimes added by individual preference. Another variation is cold brew coffee , sometimes known as "cold press". Cold water is poured over coffee grounds and allowed to steep for eight to twenty-four hours. The coffee
6580-403: The ground coffee in the sock to be reused. A vacuum brewer consists of two chambers: a pot below, atop which is set a bowl or funnel with its siphon descending nearly to the bottom of the pot. The bottom of the bowl is blocked by a filter of glass, cloth or plastic, and the bowl and pot are joined by a gasket that forms a tight seal. Water is placed in the pot, the coffee grounds are placed in
6674-471: The ground coffee unless used to grind very large amounts as in a commercial operation. A fine grind allows the most efficient extraction but coffee ground too finely will slow down filtration or screening. Ground coffee deteriorates faster than roasted beans because of the greater surface area exposed to oxygen. Many coffee drinkers grind the beans themselves immediately before brewing. Used coffee grounds can be reused for hair care or skin care as well as in
6768-605: The grounds from going to waste, including Starbucks ' "Grounds for your Garden" project, and community sponsored initiatives exist, such as "Ground to Ground" or the 'Green Coffee Shop Scheme' in Cambridgeshire, UK. In divination and fortune-telling , the patterns of coffee grounds are used for predictions. Dried used coffee grounds were recommended to fill pincushions . Used coffee grounds have other homemade uses in wood staining , air fresheners , and body soap scrubs. Initiatives have succeeded using coffee grounds as
6862-426: The grounds with methane and a catalyst, or by using the grounds to feed bio-producing algae. In concrete making, 10-15% of the sand used may be replaced with used coffee grounds. It has been suggested to recover caffeine from used coffee grounds for commercial applications in agrifood , cosmetic, nutraceutic or pharmaceutic industries. In 2021, Gloucestershire-based football club Forest Green Rovers trialed
6956-461: The grounds, which then very slowly pass through a filter. Unlike the cold press (which functions similar to a French Press) which takes eight to twenty-four hours, a Cold Drip process only takes about two hours, with taste and consistency results similar to that of a cold press. Espresso is made by forcing hot water at 91–95 °C (196–203 °F) under a pressure of between 8 and 18 bar (800 and 1,800 kPa; 120 and 260 psi), through
7050-484: The heat. It may be very briefly brought to the boil two or three times. Turkish coffee is sometimes flavored with cardamom , particularly in Arab countries. The resulting strong coffee, with foam on the top and a thick layer of grounds at the bottom, is drunk from small cups. A cafetière , or French press, is a tall, narrow cylinder with a plunger that includes a metal or nylon fine mesh filter. The grounds are placed in
7144-546: The heated water and produce a bitter, harsh, "over-extracted" taste. At the other extreme, an overly coarse grind will produce weak coffee unless more is used. Due to the importance of a grind's fineness, a uniform grind is highly desirable. If a brewing method is used in which the time of exposure of the ground coffee to the heated water is adjustable, then a short brewing time can be used for finely ground coffee. This produces coffee of equal flavor yet uses less ground coffee. A blade grinder does not cause frictional heat buildup in
7238-432: The high lignin content makes this an undesirable use. Coffee grounds may be used industrially in biogas production or to treat wastewater . Bioethanol may also be produced from the sugar content of spent coffee grounds, after it is defatted as a pre-treatment, it is typically hydrolysed by dilute acid. Biodiesel may be produced from coffee grounds, either directly by extracting the oils using solvents, by mixing
7332-400: The late 19th century, used coffee grounds were used to adulterate pure coffee. Most used coffee grounds are similar in chemical composition, although coffee grounds used to make instant coffee have fewer chemicals in them due to a more extensive extraction process. Used coffee grounds are rich in sugars, which comprise about half of their weight. A further 20% is made up of proteins, and
7426-489: The less pleasing odor and taste of green coffee versus roasted coffee. Commercial success was realized by Starbucks in creating Green Bean Refreshers using a process that primarily isolates the caffeine from the green beans but does not actually use steeped liquid from the beans. Many consumers experiment with creating green bean "extract" by steeping green coffee beans in hot water. Often, the recommended times of steeping (20 minutes to 1 hour) extract too much caffeine to provide
7520-478: The liquid coffee extraction must be separated from the used grounds , and finally, if desired, the extracted coffee is combined with other elements of the desired beverage, such as sweeteners, dairy products, dairy alternatives, or toppings (such as shaved chocolate). Coffee is usually brewed hot, at close to the boiling point of water, immediately before drinking, yielding a hot beverage capable of scalding if splashed or spilled; if not consumed promptly, coffee
7614-418: The mucilage and pulp surrounding the seed. Once the seeds are excreted by the civet, they can be harvested, processed and sold as a niche product . Once they are finally processed, these beans are called kopi luwak , and are often marketed as a rare and expensive coffee. The term "green coffee bean" refers to unroasted mature or immature coffee beans. These have been processed by wet or dry methods to remove
7708-425: The outer pulp and mucilage and have an intact wax layer on the outer surface. When immature, they are green. When mature, they have a brown to yellow or reddish color and typically weigh 300 to 330 mg per dried coffee bean. Nonvolatile and volatile compounds in green coffee beans, such as caffeine , deter many insects and animals from eating them . Further, both nonvolatile and volatile compounds contribute to
7802-400: The perceived character of the brewed coffee. Principally, dairy products mute delicate aromas and thicken mouthfeel (particularly when frothed), while sweeteners mask astringency and bitterness. Roasting coffee transforms the chemical and physical properties of green coffee beans . When roasted, the green coffee bean expands to nearly double its original size, changing in color and density. As
7896-534: The polysaccharides, making the green coffee bean more resistant to physical breakdown and less soluble in water. The molecular weight of the arabinogalactan in coffee is higher than in most other plants, improving the cellular defense system of the digestive tract compared to arabinogalactan with lower molecular weight. Free monosaccharides are present in mature brown to yellow-green coffee beans. The free part of monosaccharides contains sucrose (gluco-fructose) up to 9000 mg/100 g of arabica green coffee bean,
7990-400: The primary feedstock for the worms. Used coffee grounds are particularly noted as a soil amendment . Spent coffee grounds have phytotoxic properties which can be reduced through composting. Gardeners have reported the use of used coffee grounds as a borer, slug and snail repellent, but this has not yet been scientifically tested. Some commercial coffee shops run initiatives to prevent
8084-501: The process is to not leave the coffee in the French press for too long after pressing. Boiling, decoction or maceration , was the main method used for brewing coffee until the 1930s and is still used in some European and Middle Eastern countries. The aromatic oils in coffee are released at 96 °C (205 °F), which is just below boiling, while the bitter acids are released when the water has reached boiling point. The simplest method
8178-456: The range of 15–18:1 by mass; even within this fairly small range, differences are easily perceived by an experienced coffee drinker. Processes can range from extremely manual (e.g. hand grinding with manual pour-over in steady increments) to totally automated by a single appliance with a reservoir of roast beans which it automatically measures and grinds, and water, which it automatically heats and doses. Another common style of automated coffee maker
8272-407: The ratio of water to coffee and the fineness of the grind, but is typically weaker in taste and contains a lower concentration of caffeine than espresso, though often (due to size) more total caffeine. By convention, regular coffee brewed by this method is served by some restaurants in a brown or black pot (or a pot with a brown or black handle), while decaffeinated coffee is served in an orange pot (or
8366-668: The roasted beans. Proteins account for 8% to 12% of dried green coffee beans. A majority of the proteins are of the 11-S storage kind (alpha – component of 32 kDa, beta – component of 22 kDa), most of which are degraded to free amino acids during maturation of green coffee beans. Further, 11-S storage proteins are degraded to their individual amino acids under roasting temperature, thus are an additional source of bitter components due to generation of Maillard reaction products. High temperature and oxygen concentration and low pH degrade 11-S storage proteins of green coffee beans to low-molecular-weight peptides and amino acids. The degradation
8460-487: The surface of the coffee, which can be avoided by dribbling cold water onto the "floaters" from the back of a spoon. If the coffee beans are not ground finely enough, the grounds do not sink. A modern variant of this method is utilized by the German Empot (2014), a specially formed porcelain coffee pot with a reservoir at its bottom to hold back the sunken coffee grounds when pouring the finished coffee. "Cowboy coffee"
8554-1409: The typical pleasant aroma of coffee are generated, which are not present in fresh green coffee. During roasting, the major part of the unpleasant-tasting volatile compounds are neutralised. Unfortunately, other important molecules such as antioxidants and vitamins present in green coffee are destroyed. Volatile compounds with nauseating odor for humans have been identified, including acetic acid (pungent, unpleasant odor), propionic acid (odor of sour milk, or butter), butanoic acid (odor of rancid butter, present in green coffee with 2 mg/100 g coffee beans), pentanoic acid (unpleasant fruity flavor, present in green coffee at 40 mg/100 g in coffee beans), hexanoic acid (fatty-rancid odor), heptanoic acid (fatty odor), octanoic acid (repulsive oily rancid odor); nonanoic acid (mild nut-like fatty odor); decanoic acid (sour repulsive odor), and derivatives of such fatty acids – 3-methyl-valeric acid (sour, green-herbaceous, unpleasant odor), acetaldehyde (pungent-nauseating odor, even when highly diluted, present in dried green coffee beans at concentrations of about 5 mg/kg), propanal (choking effect on respiratory system, penetrating-nauseating), butanal (nauseating effect, present in dried green coffee beans at 2–7 mg/kg), or pentanal (very repulsive nauseating effect). Used coffee grounds Used coffee grounds
8648-426: The water is introduced to the coffee grounds: decoction (through boiling ), infusion (through steeping ), gravitational feed (used with percolators and in drip brewing ), or pressurised percolation (as with espresso ). Brewed coffee, if kept hot, will deteriorate rapidly in flavor, and reheating such coffee tends to give it a "muddy" flavour, as some compounds that impart flavor to coffee are destroyed if this
8742-493: The water, so no extra filtering is required. Malaysian and some Caribbean and South American styles of coffee are often brewed using a "sock," which is actually a simple muslin bag, shaped like a filter, into which coffee is loaded, then steeped in hot water. This method is especially suitable for use with local-brew coffees in Malaysia, primarily of the varieties Robusta and Liberica which are often strong-flavored, allowing
8836-421: Was in almost universal use in the United States prior to the 1970s, and is still popular in some households today, differs from the pressure percolator described above. It uses the pressure of the boiling water to force it to a chamber above the grounds, but relies on gravity to pass the water down through the grounds, where it then repeats the process until shut off by an internal timer. Some coffee aficionados hold
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