THE EVOLUTION OF COFFEE APPARATUS Page 13

The subject of quick roasting has greatly agitated German and French coffee men. Otto found that coffee roasted in small quantities (say fifty grams) on a sample-roaster produced a finer flavor and aroma than that roasted in the big machines. He set out to produce a machine that would roast continuous small quantities in the shortest time. He built the first commercial machine under his patent in 1893. It was shown at the International Food Exhibition in Dresden in 1894. The latest type manufactured by Max Thurmer, Dresden, in which firm Otto is a partner, has a spiral five meters long and an hourly production of about 450 pounds. The Thurmer machine, as it is called, has been sold to the trade since 1914.

Quick roasting is gone in for quite extensively in Germany, even in the big trade-roasting plants, where machines to roast in ten to seventeen minutes are common. Natural, slow cooling is most necessary with quick roasting, according to Thurmer. On the other hand, A. Mottant, of Paris, who also manufactures a line of quick gas-roasting machines, called Magic, argues that quick cooling is essential after quick roasting. Three of the Mottant machines are illustrated on pages 642 and 644.

Other quick-roasting machines of German make are the Combinator, Tornado, and Rekord.

In a lecture before the Society of Medical Officers of Health, London, October 24, 1912, William Lawton demonstrated to the satisfaction of his audience that coffee could be roasted in 3 minutes, using a perforated gas-roaster of his own invention.

The first direct-flame gas coffee roaster in America was installed in the plant of the Potter-Parlin Co., New York, by F.T. Holmes, in 1893. This was Tupholme's machine, patented in England in 1887, and in the United States in 1896–97. The Potter-Parlin Co. subsequently placed the Tupholme machines throughout the United States on a daily rental basis, limiting its leases to one firm in a city, having obtained the exclusive American rights from the Waygood, Tupholme Co., now the Grocers Engineering and Whitmee, Ltd.

An English Gas Coffee-Roasting Plant
The machines are the Morewood (Improved Faulder) sliding-burner indirect type

Natural gas was first used in the United States as fuel for roasting coffee in 1896, when it was introduced under coal roasting cylinders in Pennsylvania and Indiana by improvised gas burners.

French Globular Roaster

Edwin Crawley and W.T. Johnston, Newport, Ky., assignors to the Potter-Parlin Co., New York, were granted four United States patents on gas coffee-roasting machines.

In 1897, a special gas burner, not to be confused with the direct-flame machine, was first attached to a regular Burns roaster in the United States, and was made the basis of application for a patent.

In 1897–99, David B. Fraser, of New York, began to market in the United States a central-heated gas-fuel machine with an inner wire-cloth cylinder to keep the coffee from dropping into the flame, developed under United States patents granted to Carl H. Duehring, of Hoboken, in 1897, and to D.B. Fraser in 1899.

M.F. Hamsley, of Brooklyn, was granted a United States patent on an improved direct-flame gas roaster in 1898.