GB691845A - Improvements in or relating to a process for the manufacture of coffee extracts in the form of soluble powder - Google Patents

Abstract

In the preparation of a water soluble powdered extract of coffee, freshly roasted and ground coffee is first mixed with water (or ice and water) at a temperature below 15 DEG C., then successively percolated with further cold water to produce a solution containing 18 to 20 per cent of solid matters. This first extract is preserved at a temperature between 6 and 10 DEG C. The part-extracted coffee is then subjected to an extraction with hot water under pressure and at a temperature of 130 to 140 DEG C. This second extract is concentrated in vacuo at a temperature below 40 DEG C. to produce a solution containing about 45 per cent of solid matters, which is then mixed with the first solution, the mixture being pulverised in an atomiser so as to be reduced to a powder. As an alternative, the second extract may be reduced to a powder which is dissolved in the first extract, the resultant being reduced to powder. An anti-oxidant, e.g. glucose or formaldehyde, may be added to the concentrated solution, and in addition about 1/2 per cent of citric or tartaric acid or the potassium or sodium salt thereof may be added to either one of the solutions before forming into powder. The powder may also be mixed with a predetermined quantity of a soluble carbo-hydrate or poly-alcohol to increase its bulk and facilitate the measuring of the small quantities required for use.