Given the choice, most people would prefer
the taste of fresh ground coffee rather than instant freeze dried
coffee but nonetheless the freeze dried coffee market is vast both
domestically and commercially.
It's sheer convenience and ease of use is probably its main
advantage and with the improvements of modern production processes
the flavour of the final beverage has improved dramatically. Just
add a spoonful of freeze dried coffee granules to a mug, add hot
water and you can enjoy a decent cup of coffee.
We have all probably drunk freeze dried coffee at some stage, but
what actually is it and how is it made?
Initially fresh brew coffee is made in the usual way using a very
large industrial bulk brewer in which very hot water is passed
though fresh coffee grounds in a filter system to produce the hot
coffee liquor we are all familiar with.
This coffee liquor is then concentrated through a series of
evaporators under vacuum where some of the aroma and flavour
compounds are also removed and stored. This ensures that some of
the flavour and aroma of the coffee that is lost during the freeze
drying process can be 'put-back' into the final product just before
packing.
The concentrated coffee liquor then moves on to the actual
freeze-dry processing equipment. Here the coffee liquor is
initially foamed and then frozen to a temperature of -50 degrees
centigrade. It is then ground to the required particle size. The
ice crystals that formed in the freezing process from the water
content in the beverage are then removed in a process called
sublimation. Here the frozen granules are subjected to a high
vacuum which results in much of the water ice content to be
transformed directly into gas (without a liquid stage it would
normally undergo) before being returned to room temperature.
The resulting freeze dried coffee typically contains just 3 to 5
percent water. The more volatile flavour and aroma compounds
extracted at the initial brewing stage are then returned to the
dried product just before packing.
As you can imagine an industrial factory producing freeze dried
coffee produces vast amounts of used coffee grounds in the
production process, but these are not put to waste. They are
usually sold on as animal feed, compost or organic fuel.
It should be noted that freeze dried coffee is different from spray
dried coffee and is generally accepted as superior in quality. The
spray dried production of coffee will be the subject of another
article.
View the Cafe Bar freeze dried coffee range
here.
Written by Fenton Wayne - (Fenton Wayne is an independent advisor
in the coffee and vending trade where he has over 25 years
experience. This article has been submitted to and distributed
by www.submityourarticle.com)