Coffee extraction process

摘要

A process for forming a coffee extract particularly suitable for preparing a soluble decaffeinated coffee is disclosed. Roast and ground coffee is charged to a series of extraction columns. Certain columns are pressurized with steam (50 to 250 psig) for about 5 to about 45 minutes to increase the acidity of the coffee. The remaining roast and ground coffee is not steamed. Each of the coffees is separately extracted, preferably in a countercurrent fashion. The extract from the steamed columns is kept separate from the extract from the unsteamed columns. The extract from the steamed column has a pH of below 4.6, while the extract from the unsteamed columns has a pH of about 5.0. The extract from the unsteamed coffee is stripped with steam to form a flavor volatile condensate. Both coffee extracts are then combined, decaffeinated, and concentrated. Concentration of the combined extracts removes off-flavor volatiles which are present in the steamed extract. The flavor volatile condensate collected from the unsteamed coffee extract is added back to the concentrated combined extract. The concentrated extract can then be dried in a conventional manner to produce a soluble coffee product.