GB658806A - Improvements in or relating to concentrated coffee extracts - Google Patents

Abstract

658,806. Coffee. AMERICAN HOME FOODS, Inc. Jan. 25, 1949, No. 2008. [Class 129] Aqueous extract of coffee is prepared by passing hot water through a number of percolators containing ground roasted coffee in a series of progressively less exhausted stages of extraction in the direction of travel of the water, the initial stages being at a temperature of 125‹-150‹C and the final stages being at about 15y-20‹C. Cold water delivered by a variable-delivery pump 8 is heated in a heat-exchanger 9a to between 125‹ and 150‹C and passed through a percolator 1a containing ground roasted coffee retained between screens 2a, 2b. The process is repeated in percolators 1b, 1c, the temperature being maintained by heat-exchangers 9b, 9c. In an intermediate section comprising percolators 1p, 1q, 1r, the temperature is allowed to fall gradually to below 50‹C, say about 40‹C. but not lower than 25‹C. In the final section, comprising percolators 1y, 1z, the temperature is maintained at below room temperature by heat-exchangers 17. The process is worked in counter-current fashion, each percolator coming into operation at the end of the series and progressively changing its station until it reaches the beginning, after which it is disconnected for recharging. Each percolator is associated with a percolator (not shown in the intermediate section) provided with both hot and cold water supplies so that the appropriate temperature can be maintained. Each percolator is charged through a manhole 5 from a hopper 4 which may be movable so that it can be brought over any desired percolator. After the air in a freshly-charged percolator has been expelled by the rising liquid, a valve in an air vent 21 is closed. There may be 12-16 percolators, with 4-7 in the hot section, 5-8 in the intermediate section, and 2-4 in the cold section. The extract may be dried to a powder, as by spray drying.