Coffee aroma condensation process

Abstract From the Canadian patent

Aroma-bearing carbon dioxide gases given off during the processing of coffee, such as the roasting of green coffee, the comminution of freshly roasted coffee beans, or the percolation of roasted coffee and entrained, in a non-condensable gas such as air are cryogenically, condensed to a frost. Condensation may occur in a liquid nitrogen-cooled scraped-wall heat exchanger from which frost is collected. The uncondensed gases are vented through a filter member which collects particles of entrained frost. These particles form a bed of frost that absorbs and/or adsorbs aromas which would normally be lost.