At the 1916 meeting, Dr. Floyd W. Robison of the Detroit Testing Laboratories, read a notable paper entitled "What do we know about coffee?," which hailed coffee as a food product, warned the roasters to beware of half-facts, and urged the importance of a research laboratory. It was published and given distribution by the association.
The educational exhibit box showing samples of coffee from plantation to cup, including five different grinds, was issued in 1917, and sold for one dollar.
The Better Coffee Making Committee also published in this year a booklet entitled Coffee Grinding and Brewing in which it summarized its work to date, and presented its special plea for cotton-cloth filters as the ideal coffee-making device.
This booklet aroused considerable discussion, particularly between those who favored the paper filter and those who, with Mr. Aborn, believed cotton cloth, such as muslin, to be the most efficient strainer. "Cotton", argued Mr. Aborn, "is an ideal sanitary strainer because it contains no chemical or questionable manufacturing element."
It was pointed out by Dr. Floyd W. Robison that while cotton cloth, such as muslin, does give a fairly clear coffee, it is not so clear as by the methods where a filter paper is used. He said:
Both methods have serious objectionable features. The muslin bag, particularly, is decidedly unsanitary, especially when used in restaurants and hotels. It is rarely kept clean, and one who has frequented restaurants and many hotel kitchens knows that it lends itself to very unclean and unsightly methods of handling. The food inspector has to check this up perhaps as often as any one feature about a restaurant.
The objection to the filter paper is not at all on the ground of sanitation. It is ideal in this respect. The claim is made, and at least, in part, substantiated, that it does hold back valuable features of the brew.
There are many points about the filter that have not been considered at all. Mr. Calkin believes that the very best type of filter is a bed of coffee itself, and I must say this has the sanction of good laboratory experience.
I.D. Richheimer[380], attacking the cotton cloth filter, said:
It is a known fact that the fats in coffee are very dense and represent twelve to fifteen percent of the coffee weight. These fats—due to the simplest chemical action of contact with air, moisture and continued heat—begin a fermentation in the completed beverage. In the cloth-filtering process—due to the rapid passage of water through grounds almost as quickly as poured—the largest percentage of fats is carried into the beverage. Fat being lighter than water rises to the top of water if given a certain amount of time during the brewing process. Were there no fats (which ferment) in coffee there would be no need for placing cloth-filtering material under water, as suggested, to keep them from becoming sour.