How the Tru-Bru Pot Operates
Muller's "art" (the apparatus is described in [chapter XXXIV]) consisted in so supplying and supporting the ground coffee in an urn that it is never again subjected to the "decoction" after having been exposed to the air and steam following the first application of the water.
In 1920, William G. Goldsworthy, San Francisco, was granted a United States patent on a process for preparing the beans for making the beverage. The process consisted of grinding the raw dried beans; then packing the ground product in non-combustible and non-soluble porous containers, which are securely closed to keep them unimpaired while the contained coffee is being roasted; and, after cooling, sealing them with gelatine. To brew, container and contents are dropped into a cup of hot water.
COFFEE-MAKING DEVICES USED IN THE UNITED STATES
1—Marlon Harland Pot; 2—Universal Percolator; 3—Galt Vacuum Process Coffee Maker; 4—Universal Electric Urn; 5—English Coffee Biggin (Langley Ware); 6—Universal Cafenoira (Glass Filter); 7—Vienna (Bohemian or Carlsbad) Coffee Machine; 8—Tru-Bru Pot; 9—Tricolator; 10—Manning-Bowman Percolator; 11—Blanke's Sanitary Coffee Pot; 12—Phylax Coffee Maker; 13—Private-Estate Coffee Maker; 14—American French Drip Pot; 15—Kin-Hee Pot; 16—Silex Opalescent Glass Filter; 17—French Drip Pot (Langley Ware).
This brief review of the evolution of coffee brews shows that coffee making started with boiling, and next became an infusion. After that, the best practise became divided between simple percolation and filtration, which have continued to the present time. Boiling has also continued to find advocates in every country, even in the United States, where it seems to die hard, no matter how much is done to discredit it. Percolation devices are subdivided into the simple drip pots and the continuous percolation machines, as represented by numerous complicated and high-priced contrivances on the market. Gradually, however, true coffee lovers are realizing that the best results are to be obtained through simple percolation or simple filtration. There are good arguments for both methods.