All About Coffee

by William H. Ukers

Grinding Definitions
Powdered Like—flour.	Pulverized Like—not coarser than fine corn meal.
Very Fine and Fine Like—from corn meal to fine granulated sugar.	Medium Like—coarse granulated sugar.

Also, the committee emphasized its previous findings, particularly this one: "Filter bags should be kept in cold water when not in use. Drying causes decomposition. Keeps sweet if kept wet. Use muslin for filter bag and pulverized granulation."

The association brought out this same year, on recommendation of the committee, its Home coffee mill, an "ideal and standard coffee mill for home use." It was a wall mill equipped with a glass-front metal hopper and employing a ratchet spring-lock nut and double-action grinders. The mill was later improved with an all-glass hopper and a tumbler bracket. More than 20,000 of these mills have been sold.

At the suggestion of the author, the efficiency of nine different coffee-making devices (including boiling and drip pots, pumping percolators, cloth and paper filters) was investigated in the laboratories of the Mellon Institute of Industrial Research of the University of Pittsburgh in 1915; and Dr. Raymond F. Bacon submitted a report that showed that the boiling method produced the highest percentage of caffetannic acid and caffein; the French drip process the lowest. The investigation disclosed also a more palatable brew at 195° to 200° F. than at the boiling point.

Another notable contribution to the science of coffee brewing was made by the Home Economics Laboratories of the University of Kansas in 1916. The experiments extended over one year. They showed that strength and color in coffee brews are independent of blend and price and are most fully obtained by pulverized granulation, which was found to be the most efficient; that the consumer pays for flavor and that filtration yielded the best brew. The French drip, or true percolator, did not figure in these experiments.

At the 1915 convention of the National Coffee Roasters Association, Mr. Aborn reported that 4,000 copies of the committee's findings on grinding and brewing had been given away: and the facts were further circulated in 2,000,000 booklets issued during two years. He told of tests which showed that while there might be reasons of commercial expediency for packing ground coffee, it could not be defended as a quality principle; also that plate-grinders produced a more efficient drawing granulation than roller grinders, and that the idea that the steel-cut process eliminates dirt was an absurdity, as "the finest ground coffee is not dirt but coffee in its most efficient drawing condition." He added, "I have paid no attention to chaff removal in these tests as the uselessness of such removal has been repeatedly shown up." The reference here was to his 1914 and 1913 reports, in which it was stated that "removing the chaff in the steel-cut process does not remove any of the tannin, and for this purpose the steel-cut process is wholely futile, and a wasteful and unnecessary tax upon cost", and that "the removal of the chaff appreciably affects the flavor and depreciates the cup value."

This report repeated previous findings against the pumping percolator as producing an inefficient brew and being a very faulty utensil. Mr. Aborn concluded his report by saying:

The old time boiling method has fewer and fewer defenders and holds its own only as a superstition. I therefore pass it over as a discarded issue.... It is but repetition of former reports for me to say that pulverized granulation is the most efficient granulation; that it assures the highest quality of brew and the lowest proportion of coffee to a given strength; that it is the most saving and most satisfying grinding for all to use; that it (the coffee) must be fresh ground; that the filtration method is the most correct in fundamental principles and that used with a muslin bag it assures the consumer coffee of the purest, finest flavored quality, highest health value and sure economy.

The campaign of education was continued during 1916, producing encouraging results among schools, colleges, the medical fraternity, newspapers, with the trade and the consumer. It marked the first big constructive work combining the practical and scientific phases of grinding and brewing methods. In his report at the 1916 convention of the National Coffee Roasters Association, Mr. Aborn reviewed the four years work, and pointed out what had been accomplished. He told of a new booklet, to be called the True Book on Coffee Grinding and Brewing, and an educational exhibit box for schools about to be issued. Due to opposition which developed from trade interests that were putting out steel-cut and other grinds of coffee not favored by the committee, and also because many members thought the association should not exploit any particular method of grinding or brewing, it was decided to make no further publication of the coffee grinding and brewing conclusions of the committee until they had been confirmed by laboratory research.

Boiling and filtration tests in the mountains of the Yellowstone Park by W.H. Aborn in 1916 showed that the limit of coffee brewing was reached at an altitude of nine thousand feet.