Coffee – The Social Drink Of Choice
Preparation of the Drupes
The drupes have an outer skin or exocarp of varying thickness, depending of the specie. Under the skin is the pulp or mesocarp and the husk or endocarp, a parchment-like cover around each seed.
In the preparation of the coffee drupes the skin and pulp are first removed, by either a dry method or a wet method, the latter either with or without fermenting. The wet method with a brief fermenting period normally delivers a better quality. Although with some arábica varieties it is cost effective to dry the entire fruit and run it through the huller, a mechanical processor, which normally removes the husk.
The wet method causes lots of contamination, therefore care should be taken to contain the discarded skin and pulp in ponds and let the water drain from there. This material is useful as a medium to grow rice straw mushrooms, Volvariella volvacea
In other species, with larger seeds or so-called beans, the process is separate. First removing skin and pulp and after a drying period the husk is removed in the huller. The husk can be used for burning in ovens.
Finally the silver skin is removed, using brushes and blowers. The seeds need to be dried to a proper moister content and stored in jute bags of 60 kg. Care should be taken that the storage room is properly ventilated, to avoid investment by fungi, like Aspergillus flavus, producing the carcinogen Afla toxin.
Coffee beans should also be protected, to avoid investment by insects and rodents, damaging and contaminating the seeds.
Caffeine is the main ingredient in the coffee, known by the scientific name of 1,3,7-trimethylxanthine, with the isomers Xanthines, Theobromine also stimulant in Cacao, and Theophylline.
Caffeine is the most widely used psycho-stimulant in the world, with physiological effects as:
- Slightly diuretic
- Dilation of the coronary vessels
- Stimulation of the central nervous system
- Stimulation of gastric acid secretion
- Elevation of free fatty acids and glucose
Because of these effects it is frequently advised to patients, with medical conditions, to consume decaffeinated coffee
The process of decaffeination is done in the green coffee stage. The Europeans and Canada have a standard for decaffeinated coffee of 0.01% in the beans and 0.03% in instant coffee. Internationally de standard is 3%, i.e. 3% caffeine remains in the beans.
Although it is denied, in my opinion some of the taste and flavor is lost in this process. The drinking of decaf coffee, as is popularly called, is specially for people who really cannot take caffeine for whatever reason. Fact is that caffeine is metabolized by the liver and although it varies significantly between the individual. Younger man normally get rid of it very soon, slower in women and the slowest in pregnant women.
The four methods of decaffeination are:
- Water Method, where the caffeine is forced out of the swollen beans with vapor
- The Ethyl-Acetate Method
- The Carbon Dioxide Method
- The Methylene Chloride Method
There also exist a standard for residues of the chemicals and as reported the flavor is the best guarded with the latter method.
WARNING! Studies of decaffeinated coffee samples, found varying quantities of caffeine. It is logical, as with the various blends and methods of roasting, grinding, extraction and decaffeination, the caffeine content in the basic products varies significantly. If for whatever reason, one needs to lower the intake of caffeine, it is advisable to lower the amounts of decaffeinated cups consumed as well.
The Process of Roasting
The process of roasting is a very crucial one for the flavor of the coffee. In the first place the beans need to be selected carefully to be of near equal size and then the amount of heat and the time of the roasting should be monitored closely.
Here comes also the special roasting instruction for Caracolillo (Peaberry) beans, which don’t have the flat side. and are rolling more evenly through the roaster. Because of this fact, the roasting time can be slightly reduced.
The moment the oil starts coming out of the beans the roasting must stop and the cooling should follow swiftly. The sound of the beans rolling over each other sounds like broken glass. And that is just right. Do not burn the oil nor the near twenty organic acids and loosing the caffeine up to 38%. The acids can be sufficiently neutralized, with a simple additive, during extracting, which also enhances the taste.
Anyway watch out for carbonizing the beans, which may provoke health issues. All these issues are described in my booklet, “Coffee – From Roast to the Ideal Cup“, available at Amazon.
One possible health risk of Dark Roasting is the formation of Acrylamide, a Neuro Toxin. The health risks of this substance is still under investigation in the USA and in Europe, but it has the potential of being Carcinogenic and causing changes in DNA.
It starts forming at temperatures around 120°C and is decomposed above 175°C, but in between, many elements of taste and flavor are also burned.
For this reason you may find lower Acrylamide contents in Dark Roast than normal Roast. Brewing also decomposes Acrylamide to some extent.
I definitely do not agree to the special roasts for special styles. The roasting should be equal for whatever style. Roasting beyond the second crack, starts to burn the oils and the organic acids and the caffeine, which are essential for the flavor and aroma. The fineness of the grinding should differ for the way of extracting the coffee such as cooking, drip, percolation or forced steam method etc. These processes are in full described in my booklet.
To enjoy a good cup of coffee one should grind the amount needed to extract to preserve the flavor in the whole beans, if vacuum packing is not an option. The Dutch gained lots of experience in the more than three hundred years of coffee trade. The well known blends of the various brands speak for themselves.
Canéphora var.Robusta, after roasting, has a strong, full body flavor, but a little bitter due to the higher caffeine content, almost twice as high as that of arábica. It is a good candidate for blends and I definitely not consider this as being inferior in quality. The taste and flavor of the arabicas is mild.
World Coffee Consumption
In 2011 the world consumed 7.9 million metric tons, which is 2% less than in 2010 and practically equal to 2009. Importing countries were the highest consumers with around 69% and producing countries 31%.
The consumption per capita is in my opinion not accurate looking at the conflicting data reported by different organizations. Clear is that the European countries are the highest consumers, with absolute higher consumption in the Scandinavian countries and Finland around the 12kg per capita. More to the South the consumption is lower to about 5kg per capita and the consumption in the USA around 4kg.
Fact is that more and more young people start drinking coffee, probably becoming a social drink of choice with the rising number of specialized coffee shops.
- Coffee cultivation, harvesting and production
- Coffee processing, roasting and consumption
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