# US 4,397,873 A · Dark-colored freeze dried coffee

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- Number: US 4,397,873 A
- Document ID: US4397873A
- Status: Granted
- Kind: A
- Application number: 06/353,280
- Filed: 1982-03-01
- Granted: 1983-08-09
- Earliest claimed: 1982-03-01
- Assignees: General Foods Corporation
- Inventors: Stephen F. Hudak
- Web page: https://patentgrep.com/patent/US4397873A

## CPC

- A23F 5/32: by lyophilisation
- A23F: COFFEE; TEA; THEIR SUBSTITUTES; MANUFACTURE, PREPARATION, OR INFUSION THEREOF

## Abstract

A dark-colored freeze dried coffee is produced by using a multi-step process to freeze the coffee extract. The coffee extract is chilled to a temperature at which an ice slush forms. The slushed extract is heated in order to melt some of the slush and subsequently re-chilled. This procedure may be repeated one or more times prior to chilling the extract below its eutectic point and freeze drying the frozen extract.

## Claims

### Claim 1

A process for producing a dark-colored freeze dried coffee which comprises:
(a) rapidly chilling an aqueous coffee extract to a temperature between -2.degree. C. and -5.degree. C. whereby a slush forms;
(b) heating said slushed extract to a temperature slightly below 0.degree. C. whereby some of the slush begins to melt;
(c) re-chilling the heated extract of step (b) to a temperature from -2.degree. C. to -5.degree. C. and repeating the heating and re-chilling steps one or more times;
(d) further rapidly chilling said extract to a temperature below its eutectic point whereby the coffee extract is frozen solid; and
(e) freeze drying the frozen extract.

### Claim 2 (depends on 1)

The process of claim 1 which further comprises stirring the coffee extract while re-chilling it to a temperature from -2.degree. C. to -5.degree. C.

### Claim 3 (depends on 1)

The process of claim 1 wherein the rapid chilling of step (a) of claim 1 is carried out in a scraped surface heat exchanger maintained at approximately -10.degree. C.

### Claim 4 (depends on 1)

The process of claim 1 wherein the chilling of the extract below its eutectic point of step (c) of claim 1 is carried out on a continuous, chilled moving metal belt.