Sunday, July 31, 2011

Coffee Harvesting in Brazil, 1913

Brazilian Coffee Farm 1913 This is an interesting description of the process of harvesting and preparing coffee beans for market in Brazil, from "Across Unknown South America", by A. Henry Savage-Landor, 1913

The collection of the berries is the busiest process in the fazendas, and has to be performed with considerable care, for some of the berries are already ripe and dried when others hidden under the branches have not yet reached the required degree of maturity. An experienced hand can collect from 400 to 450 litres of coffee berries per day. It takes an average of 100 litres of coffee berries to produce 15 kilos of prepared coffee beans ready to be shipped. The crop is not the same every year. After one plentiful crop there generally succeeds one year, sometimes two or three, of poor—almost insignificant—collections, varying according to the care that is taken of the trees and the soil.

When once the coffee has been collected and transported to the fazenda in baskets, blankets and sheets, it is necessary to remove the skin and viscous pulpy matter which envelop the beans. This is done partly by maceration in water tanks, and afterwards by drying upon extensive flat terraces, tiled or cemented, and locally called terreiro. The process of drying by machinery has not been adopted in Brazil; principally because of its high cost. The coffee is first placed for some days in mounds on the terraces, until fermentation of the outer skin begins, which afterwards hastens desiccation when coffee is spread flat in a thin layer on the terraces. When once the coffee berries have been freed from their pulpy envelope and skin, the desiccation—if the weather is propitious—takes place in a few days. Care must be taken to move the berries constantly, so that they dry evenly on all sides, as perfect desiccation is necessary in order to preserve the coffee in good condition after it is packed for shipment.

There are two ways of preparing coffee for export—the humid and the dry. In the humid process the berries are placed in a special machine called despolpadore, which leaves the beans merely covered and held together in couples by the membrane immediately enclosing them after the skin and viscous sugary coating have been removed. Those coffees are called in commerce, lavados, or washed.

The dry process consists, after the berries have been skinned and dried, in removing part of the pulp and membrane in a special machine and a series of ventilators. They are then quite ready for export.

The preparation of coffee from the drying terraces is slightly more complicated. The coffee passes through a first ventilator, which frees it from impurities such as earth, stems, stones, filaments, etc.; from this it is conveyed by means of an elevator into the descascador, where the membrane is removed. Subsequently it passes through a series of other ventilators, which eliminate whatever impurities have remained and convey the coffee into a polishing machine (brunidor). There the coffee is subjected to violent friction, which not only removes the last atoms of impurity but gives the beans a finishing polish. The coffee is then ready for the market.

Friday, July 1, 2011

Brew, Don't Boil

The old-time boiling method of making coffee has gone out of style, because the average consumer is becoming aware of the fact that it does not give a drink of maximum efficiency. Boiling the ground coffee with water results in a large loss of aromatic principles and a bitter flavor to the beverage. Also, the maintenance of a high temperature by the direct application of heat has a deleterious effect upon the substances in solution. This is also true in the case of the percolator, and any other device wherein the solution is caused to pass directly into steam at the point where heat is applied. Warm and cold water extract about the same amount of material from coffee; but with different rates of speed, an increase in temperature decreasing the time necessary to effect the desired result.

It is a well known fact that re-warming a coffee brew has an undesirable effect upon it. This is very probably due to the precipitation of some of the water-soluble proteins when the solution cools, and their subsequent decomposition when heat is applied directly to them in reheating the solution. The absorption of air by the solution upon cooling, with attendant oxidation, which is accentuated by the application of heat in re-warming, must also be considered. When an extract of coffee cools upon standing, some of the aromatic principles separate out and are lost by volatilization.

The method of extracting coffee which gives the most satisfaction is practised by using a grind just coarse enough to retain the flavoring components, retaining the ground coffee in a fine cloth bag, as in the urn system, or on a filter paper, and pouring water at boiling temperature over the coffee. During the extraction, a top should be kept on the device to minimize volatilization, and the temperature of the extract should be maintained constant at about 200° F. after being made. Whether a repouring is necessary or not is dependent upon the speed with which the water passes through the coffee, which in turn is controlled by the fineness of the grind and of the filtering medium.