Drip Brew Coffee: A Widely Used Method of Coffee Brewing

Drip brewing, or filtered coffee, is a method for brewing coffee which involves pouring water over roasted, ground coffee beans contained in a filter. Water seeps through the coffee, absorbing its oils and essences, solely under gravity, then passes through the bottom of the filter. The used coffee grounds are retained in the filter with the liquid falling (dripping) into a collecting vessel such as a carafe or pot.

Paper filters (invented in Germany by Melitta Bentz in 1908) are commonly used for drip brew all over the world. One benefit of paper filters is that the used grounds and the filter may be disposed of together, without a need to clean the filter. However, metal filters are also common, especially in India. These are made of thin perforated metal sheets that restrain the grounds but allow the coffee to pass, thus eliminating the need to have to purchase separate filters which sometimes cannot be found in some parts of the world. Additionally, many machines now use permanent plastic filters, which are made of a fine mesh. These of course add to the maintenance of the machine, but reduce overall cost and produce less waste.

Drip brewing is a widely used method of coffee brewing, particularly in North America owing to the popularity of domestic coffeemakers. There are, however, several manual drip-brewing devices on the market, offering a little more control over brewing parameters than automatic machines. One example is the Clever Coffee Dripper, which has a patented stopper valve, allowing the user to control steeping time and the proportion of coffee to water. The device is popular amongst baristas at respected coffee bars like San Francisco's Four Barrel Coffee, New York's Gimme Coffee! and D.C.'s Chinatown Coffee. There also exist small, portable, single serving drip brew makers that only hold the filter and rest on top of a cup. Hot water is poured in and drips directly into the cup.

Brewing with a paper filter produces clear, light-bodied coffee, which is free of sediments, although lacking in some of coffee's oils and essences, which are trapped in the paper filter. Among these are certain diterpenes that appear to increase risk of coronary heart disease. Metal filters do not remove these components. [source : Drip Brewed Coffee]

The Origin of The Irish Coffee

Irish coffee (Irish: Caife Gaelach) is a cocktail consisting of hot coffee, Irish whiskey, and sugar, stirred, and topped with thick cream. The coffee is drunk through the cream. The original recipe explicitly uses cream that has not been whipped, although whipped cream is often used. Irish coffee may be considered a variation on the hot toddy.

The origin of the Irish coffee is highly disputed. According to certain sources the original Irish coffee was invented by Joseph Sheridan, a head-chef at Foynes, County Limerick but originally from Castlederg, County Tyrone. Foynes' port was the precursor to Shannon International Airport in the west of Ireland; the coffee was conceived after a group of American passengers disembarked from a Pan Am flying boat on a miserable winter evening in the 1940s. Sheridan added whiskey to the coffee to warm the passengers. After the passengers asked if they were being served Brazilian coffee, Sheridan told them it was Irish coffee.

Stanton Delaplane, a travel writer for the San Francisco Chronicle, brought Irish coffee to the United States after drinking it at Shannon Airport, when he worked with the Buena Vista Cafe in San Francisco to start serving it on November 10, 1952, and worked with the bar owners Jack Koeppler and George Freeberg to recreate the Irish method for floating the cream on top of the coffee, sampling the drink one night until he nearly passed out. The group also sought help from the city's then mayor, George Christopher, who owned a dairy and suggested that cream aged at least 48 hours would be more apt to float. Delaplane popularized the drink by mentioning it frequently in his travel column, which was widely read throughout America. In later years, after the Buena Vista had served, by its count, more than 30 million of the drinks, Delaplane and the owners grew tired of the drink. A friend commented that the problem with Irish coffee is that it ruins three good drinks: coffee, cream, and whiskey.

Tom Bergin's Tavern in Los Angeles, also claims to have been the originator and has had a large sign in place reading "House of Irish Coffee" since the early 1950s. Other sources claim that Joe Jackson perfected the recipe at Jacksons Hotel, Ballybofey, Co. Donegal.

In Spain a "Café Irlandés" ("Irish Coffee") is sometimes served with a bottom layer of whiskey, a separate coffee layer, and a layer of cream on top. Special devices are sold for making Café Irlandés.

Irish coffee preparation started with warm the glass and then black coffee poured into the glass. Whiskey and at least one level teaspoon of sugar is stirred in until fully dissolved. The sugar is essential for floating liquid cream on top. Thick cream is carefully poured over the back of a spoon initially held just above the surface of the coffee and gradually raised a little. The layer of cream will float on the coffee without mixing. The coffee is drunk through the layer of cream.

To ensure the integrity of the ingredients of Irish Coffee, NSAI, Ireland's national standards body, published an Irish Standard, I.S. 417 Irish Coffee, in 1988. [source : Irish Coffee]

The Advantages of Instant Coffee

Instant coffee, also called soluble coffee and coffee powder, is a beverage derived from brewed coffee beans. Instant coffee is commercially prepared by either freeze-drying or spray drying, after which it can be rehydrated. At least one brand of instant coffee is also available in concentrated liquid form.

Instant coffee was invented in 1901 by Satori Kato, a Japanese scientist working in Chicago. Kato introduced the powdered substance in Buffalo, New York, at the Pan-American Exposition. George Constant Louis Washington developed his own instant coffee process shortly thereafter, and first marketed it commercially (~1910). The Nescafé brand, which introduced a more advanced coffee refining process, was launched in 1938.

Advantages of instant coffee include speed of preparation (instant coffee dissolves instantly in hot water), lower shipping weight and volume than beans or ground coffee (to prepare the same amount of beverage), and long shelf life, though instant coffee can also spoil if not kept dry.

Instant coffee is available in powder or granulated form contained in glass jars, sachets or tins. The user controls the strength of the resulting product, by adding more or less water (for a weaker or stronger brew). Instant coffee is also convenient for preparing iced coffee like the Greek frappé, which is popular in warmer climates and hot seasons. In some European countries such as Spain and India, instant coffee is commonly mixed with hot milk instead of boiling water.

In commercial processes the decaffeination of instant coffee almost always happens before the critical roasting process which will determine the coffee's flavour and aroma processes. Compared to overall health effects of coffee, instant coffee appears to be as efficient as filtered coffee in decreasing the risk of diabetes type 2.

Instant coffee is one of the ingredients in "Caffenol-C", a home-made, non-toxic black-and-white photographic developer. The other ingredients in the basic formula are ascorbic acid and anhydrous sodium carbonate; some recipes also include potassium bromide as a fog-reducing agent. The active ingredient appears to be caffeic acid. Initial experiments on Caffenol were performed in 1995 at the Rochester Institute of Technology; addition of ascorbic acid began around 2000, yielding the improved Caffenol-C, which is less likely to stain negatives than the original formulation. Experiments have shown that cheaper, less desirable brands of coffee work better for this application than more expensive brands. [source : Instant Coffee]

Decaf Coffee and Its Processes

Coffee Decaffeination is the act of removing caffeine from coffee beans. (While caffeine-free soft drinks are occasionally referred to as "decaffeinated", some are better termed "uncaffeinated": prepared without adding caffeine during production.) Despite removal of caffeine, many decaffeinated drinks still have around 1-2% of the original caffeine remaining in them.

Coffee Decaffeination process is usually performed on unroasted (green) beans, and starts with steaming of the beans. They are then rinsed with a solvent that extracts the caffeine while leaving the other essential chemicals in the coffee beans. The process is repeated anywhere from 8 to 12 times until it meets either the international standard of having removed 97% of the caffeine in the beans or the EU standard of having the beans 99.9% caffeine-free by mass. Coffee contains over 400 chemicals important to the taste and aroma of the final drink: it is therefore challenging to remove only caffeine while leaving the other chemicals at their original concentrations.

The first commercially successful decaffeination process was invented by Ludwig Roselius and Karl Wimmer in 1903. It involved steaming coffee beans with a brine (salt water) solution and then using benzene as a solvent to remove the caffeine. Coffee decaffeinated this way was sold as Kaffee HAG after the company name Kaffee Handels-Aktien-Gesellschaft (Coffee Trading Company) in most of Europe, as Café Sanka in France and later as Sanka brand coffee in the U.S. Café HAG and Sanka are now worldwide brands of Kraft Foods. Due to health concerns regarding benzene, this process is no longer used commercially and Coffee Hag and Sanka are produced using a different process.

The Swiss Water Process is a method of decaffeinating coffee beans developed by the Swiss Water Decaffeinated Coffee Company. To decaffeinate the coffee bean by the Swiss Water method, a batch of green (unroasted) beans is soaked in hot water, releasing caffeine. When all the caffeine and coffee solids are released into the water, the beans are discarded. The water then passes through a carbon filter that traps caffeine but lets the coffee solids pass through. The resulting solution, called "green coffee extract (GCE)" by the company, is now available for decaffeinating coffee. New green coffee beans are introduced to the GCE. Since the GCE is coffee solids without caffeine only the caffeine diffuses from the new beans. The GCE passes through proprietary carbon which captures the caffeine. The process repeats, filtering out all the caffeine until the beans are 99.9% caffeine-free. These beans are removed and dried, and thus retain most if not all of their flavor.

Although the process was pioneered in Switzerland in the 1930s, today the world's last major Swiss Water Process decaffeination facility is based near Vancouver, British Columbia,Canada. However this process is simple enough to be used locally by many coffee roasters.

In the direct method, the coffee beans are first steamed for 30 minutes and then repeatedly rinsed with either dichloromethane or ethyl acetate for about 10 hours. The solvent is then drained away and the beans steamed for an additional 10 hours to remove residual solvent. Sometimes coffees that are decaffeinated using ethyl acetate are referred to as naturally processed because ethyl acetate can be derived from various fruits or vegetables; but, because of the impracticality of gathering natural ethyl acetate, the chemical used for decaffeination is synthetic.

In the indirect method, beans are first soaked in hot water for several hours, in essence, making a strong pot of coffee. Then the beans are removed and either dichloromethane or ethyl acetate is used to extract the caffeine from the water. As in other methods, the caffeine can then be separated from the organic solvent by simple evaporation. The same water is recycled through this two-step process with new batches of beans. An equilibrium is reached after several cycles, where the water and the beans have a similar composition except for the caffeine. After this point, the caffeine is the only material removed from the beans, so no coffee strength or other flavorings are lost. Because water is used in the initial phase of this process, sometimes indirect method decaffeination is referred to as "water-processed" even though chemicals are used.

The CO₂ decaffeination process is technically known as supercritical fluid extraction. In the carbon dioxide method, the caffeine is stripped directly from the beans by a highly compressed semi-liquid form of carbon dioxide. Pre-steamed beans are soaked in a bath of supercritical carbon dioxide at a pressure of 73 to 300 atmospheres. After a thorough soaking for around ten hours, the pressure is reduced, allowing the CO₂ to evaporate, or the pressurized CO₂ is run through either water or charcoal filters to remove the caffeine. The carbon dioxide is then used on another batch of beans. This liquid works better than water because it is kept in supercritical state near the transition from liquid to gas, combining favorable diffusivity properties of the gas with increased density of a liquid. This process has the advantage that it avoids the use of potentially harmful substances.

In triglyceride process, green coffee beans are soaked in a hot water/coffee solution to draw the caffeine to the surface of the beans. Next, the beans are transferred to another container and immersed in coffee oils that were obtained from spent coffee grounds. After several hours of high temperatures, the triglycerides in the oils remove the caffeine—but not the flavor elements—from the beans. The beans are separated from the oils and dried. The caffeine is removed from the oils, which are reused to decaffeinate another batch of beans. This is a direct-contact method of decaffeination.

Almost all brands of decaffeinated coffee still contain a minimum amount of caffeine. Drinking five to ten cups of decaffeinated coffee could deliver as much caffeine as would one or two cups of regular coffee, according to research at the University of Florida Maples Center for Forensic Medicine. In one independent study of 10 popular decaffeinated coffees, researchers found that all but one contained detectable caffeine. The 16-ounce (473-milliliter) cups of coffee samples contained caffeine in the range of 8.6 milligrams to 13.9 milligrams. In another similar study of popular brands of decaf coffees, the caffeine content was anywhere from 3 milligrams up to 32 milligrams. Both of these studies tested the caffeine content of store-brewed coffee, suggesting the caffeine may be residual from the normal coffee served, rather than poorly decaffeinated coffee.

Consumption of decaffeinated appears to be as beneficial as caffeine-containing coffee in regard to all-cause mortality, according to a large prospective cohort study. In women, consumption of decaffeinated coffee significantly decreases all-cause mortality with a relative risk of between approximately 0.8 to 0.9 with a consumption of 1 up to approximately 6 cups per day, compared to those who drink less than one cup per month. In men, these beneficial effects are apparently not as great, but yet having a significant trend towards less mortality for those who drink more than 2 cups per day compared to those who drink less than one cup per month.

As of 2009, progress towards growing coffee beans that do not contain caffeine was still continuing. The term "Decaffito" has been coined to describe this type of decaffeinated coffee, and trademarked in Brazil. The prospect for Decaffito type coffees was shown by the discovery of the naturally caffeine-free Coffea charrieriana, a Coffea arabica plant, discovered in Cameroon in 2004. It has a deficient caffeine synthase gene, leading it to accumulate theobromine instead of converting it to caffeine. This trait could either be bred into other coffee plants by crossing them with Coffea charrieriana, or an equivalent effect could be achieved by knocking out the gene for caffeine synthase in normal coffee plants. [source : Decaf Coffee]