Coffee Latte

Flavours in Coffee

There are more than 1,000 aromatic compounds in coffee. The ones that make up a cup of coffee require a minimum temperature of 94°C to extract from the coffee beans since the flavours cannot dissolve below 94°C.

Instant Coffee and Coffee Concentrate
Coffee concentrate is made from fresh brewed coffee, and instant coffee is made from spray dried coffee concentrate. However, unlike instant coffee, coffee concentrate is liquid and contains the coffee flavours already dissolved in suspension. Unlike instant coffee, no hot water is required to dissolve the flavours. Coffee concentrate also tastes very close to fresh brewed coffee. Instant coffee loses a lot of the original flavours when spray dried.

1. The coffee tastes `flat', since the volatile aromas evaporate with the heat.


2. It turns sour. This is a complex reaction, involving heat and air, which causes the coffee flavours to change and break down into organic acids. The reaction is driven by heat and air, and the rate of change is approximately 3 times for every 10° C rise in temperature. Hence, a cold cup of coffee at 32°C will last 3 times longer than that at 40°C and 9 times longer than at 52°C.
   

Ice Latte

Manufacture of Coffee Concentrate
During the manufacture of coffee concentrate, the following steps are taken to ensure product quality and a shelf life of at least 6 months, and sour taste is minimized:

1. Coffee brewed in special extractors covered by a shielding gas. The shielding gas is Carbon Dioxide which prevents the hot coffee extract coming into direct contact with air.
2. The hot extract, covered with shielding gas, is immediately cooled to ambient temperature using a heat exchanger.
3. The volatile flavours released by the brewing are condensed back and added into the coffee concentrate.
4. The concentrate is packed into air-tight aluminum bags. The bags have a high barrier to oxygen penetration.
5. Heat treatment of the package follows to kill all micro-organisms.