1. Cultivation
Coffee beans are grown in some eighty countries spread over four continents around the entire globe between the Tropic of Cancer (to the North) and the Tropic of Capricorn (to the South).
The coffee plant is a small evergreen bush that bears a fruit known as coffee cherries. The flowers of the tree are small and white with resemblance to orange blossom and have a distinct pleasant perfume. The blossoms turn to green berries that gradually ripen through yellow to a deep glistening red. Each berry contains two round or oval shaped seeds, which become the coffee beans after processing.
There is a rich diversity of coffee types and flavours, however the two major species of the coffee plant that are cultivated are Coffea Arabica and Coffea Robusta.
Coffea Arabica varieties, grown primarily in Latin America, India, East Africa and Indonesia, are relatively complex in flavour. They are somewhat expensive to harvest, since individual coffee cherries must be hand picked at their peak of ripeness. Predominantly grown at high altitudes, this bean species consequently takes longer to ripen, creating the renowned complex flavours.
Coffea Robusta varieties are grown mainly in Western and Central Africa, India and South East Asia. They can be grown at lower altitudes and tend to be less susceptible to disease, making them more suitable to growing in areas and environments where Coffea Arabica cannot thrive. Coffea Robusta will commonly have more bitterness and earthy notes, and contain higher levels of caffeine.
In many ways coffee cultivation and processing is like winemaking. Coffee from different regions in a country, and sub-species within each region, may have distinctive characters such as flavour (flavour criteria includes term such as “citrus-like” or “earthy”), caffeine content, body or mouth feel and acidity.
Cupping – Taste-testing Coffee
Different coffee origins, and their combination with roast levels and grind size, create the final coffee taste, which is measured in terms of acidity, body, aroma, flavour, and crema.
Cupping is the process used to verify consistency of taste parameters is achieved over the years and the many crops used. At Robert Timms this involves tasting of every batch by experienced tasters at every stage of processing.
2. Blending
Our green beans from various regions within countries are carefully identified for their unique characteristics to create the end product. Processing techniques of the green coffee bean, either washed or natural, will also impact its final flavour in the roasted product, and this is also a key consideration for selection.
A single bean origin will generally not possess the complexity for a superior blend. Our blends contain between two to five different beans. Our oldest blend, Royal Special, was essentially developed for Queen Elizabeth II who first came to visit Australia in 1954. The blend, with its uniquely subtle qualities, is still available today.
Our experienced team, with their knowledge of each bean, artfully combines them to create the desired blend of taste and quality.
3. Roasting
It takes a lot of skill to maintain consistency when roasting coffee. The roaster must have a good feel and eye to ensure top quality. For a better and consistent roast, the beans have been sorted for size, shape and colour. This ensures that the beans roast evenly, as different sized beans roast to different colours in the same batch. As the coffee beans are gently heated, acids start to break down, and sugars are partially caramelised to provide colour, taste and body.
There are between 200 and 1,000 different flavour and aroma chemicals in a coffee bean, that uniquely combine to make coffee such a desirable product. As the beans are gently heated further, coffee oil starts to release, and acids present in the bean reduce throughout roasting. The coffee beans start cracking open as moisture escapes, and by the end of roasting will have increased substantially in size, as well as being reduced in weight.
Throughout the process carbon dioxide is released from the bean preventing oxygen getting in to it. Over time it is only with clever packing that a barrier prevents oxygen entering the coffee (which results in staling).
Roast levels are used to create different flavours. Lighter roasts tend to create more top notes, or acidic flavours, and darker roasts tend to create more depth and sweetness in the flavour.
4. Grinding
The roasted beans are ground to different grades from coarse to fine. How fine or coarse a grind is will strongly affect the brewing, for this reason you would choose a certain grind to suit your coffee equipment.
A coarser grind works best in traditional percolators, plungers, and our Instant Coffee processing plant. A finer grind suits your espresso machine.
5. Brewing
Brewing may take place using home or commercial coffee equipment.
To produce instant coffee, this entails brewing coffee in highly effective extraction equipment similar in principle to a percolator, but with more concentrated pressure. Hot filtered water is passed through a series of extraction columns containing coarsely ground coffee beans. This removes the coffee extract from the roasted ground coffee.
6. Coffee Liquor
Coffee liquor is extracted at home by use of home-brewing equipment. The home espresso machine produces the strongest commonly found coffee liquor.
For instant coffee, after a filtering step, a distillation process is used to capture the complex coffee aromas and flavours.
7. Drying
Soluble coffee is dried coffee. There are no chemical processes or additives. Instant coffee is pure coffee.
Two basic methods are available for converting the coffee liquor to a dry product ready for packing. The “Spray Dried Method” or “Freeze Dried Method”.
Spray Dried Method
Cooled, clarified liquid concentrate is sprayed through a nozzle at the top of a drying tower. Our tower is a commonly known landmark in Concord, Sydney, and is roughly 17 stories tall.
The tiny spheres of coffee form out of the nozzle, and dry as they fall through the heated air. This is then recirculated through the agglomeration phase to bind the coffee spheres with steam and water to form granulated coffee.
Freeze Dried Method
Coffee liquor is chilled to approximately –400C, and under a vacuum the water turns to gas leaving sheets of freeze dried coffee.