"Steel-cut" coffee, that is, a medium-ground coffee with the chaff blown out, does not compare in cup test with coffee that has been more scientifically ground and not given the chaff removal treatment that is largely associated in the public mind with the idea of the steel-cut process.
Machine for Automatically Packing Coffee in Cartons
Five distinct operations are performed by the units comprising this Pneumatic installation, viz., carton-feeding, bottom-sealing, lining, weighing and top-sealing
According to the results of the trade canvass previously referred to, it would appear that the terms most suited to convey the right idea of the different grades of grinding, and likely to be acceptable to the greatest number, would be "coarse" (for boiling, and including all the coarser grades); "medium" (for coffee made in the ordinary pot, including the so-called "steel-cut"); "fine" (like granulated sugar, and used for percolators); "very fine" (like cornmeal, and used for drip or filtration methods); "powdered" (like flour, and used for Turkish coffee).
Coffee begins to lose its strength immediately after roasting, the rate of loss increasing rapidly after grinding. In a test carried out by a Michigan coffee packer,[333] it was discovered that a mixture of a very fine with a coarse grind gives the best results in the cup. It was also determined that coarse ground coffee loses its strength more rapidly than the medium ground; while the latter deteriorates more quickly than a fine ground; and so on, down the scale. His conclusions were that the most satisfactory grind for putting into packages that are likely to stand for some time before being consumed is a mixture consisting of about ninety percent finely ground coffee and ten percent coarse. His theory is that the fine grind supplies sufficiently high body extraction; the coarse, the needful flavor and aroma. On this irregular grind a United States patent (No. 14,520) has been granted, in which the inventor claims that the ninety percent of fine eliminates the interstices—that allow too free ventilation in a coarse ground coffee—and consequently prevents the loss of the highly volatile constituents of the ten percent of coarse-ground particles, and at the same time gives a full-body extraction.
Making and Filling Containers
As stated before, a large proportion of the coffee sold in the United States is put up into packages, ready for brewing. Such containers are grouped under the name of the material of which they are made; such as tin, fiber, cardboard, paper, wood, and combinations of these materials, such as a fiber can with tin top and bottom. Generally, coffee containers are lined with chemically treated paper or foil to keep in the aroma and flavor, and to keep out moisture and contaminating odors.
As the package business grew in the United States, the machinery manufacturers kept pace; until now there are machines that, in one continuous operation, open up a "flat" paper carton, seal the bottom fold, line the carton with a protecting paper, weigh the coffee as it comes down from an overhead hopper into the carton, fold the top and seal it, and then wrap the whole package in a waxed or paraffined paper, delivering the package ready for shipment without having been touched by a human hand from the first operation to the last. Such a machine can put out fifteen to eighteen thousand packages a day.