Australians love their coffee. We consume more than six billion cups of coffee annually! But can you describe what it tastes like?
Southern Cross University, in conjunction with AgriFutures Australia, has unveiled a world-first coffee character sensory wheel. Published in the Journal of Sensory Studies, the research has also pinpointed the specific taste of Australian-grown coffee.
The Coffee Character Wheel is a colour-coded visual glossary of terms to describe coffee, organised by acidity, aftertaste and mouthfeel. It establishes a common language between coffee drinkers and producers.
The Coffee Character Wheel has a secondary purpose. It’s designed to help build demand for Australian-grown coffee beans. The coffee bean market in Australia is worth $1billion, yet the majority of beans are sourced internationally.
“The aim of the Coffee Character Wheel is to suggest and unify the vocabulary used for describing the acidity, mouthfeel, aftertaste, and overall characteristics of coffee that are not specifically flavour,” said Southern Cross University’s project researcher Dr Simon Williams.
And what does Australian-grown coffee taste like?
“Using the Coffee Character Wheel, Australian-grown coffee has been described as having a low-medium intensity acidity with citric acid and malic acid characters similar to apple and berry, a smooth texture and light medium body mouthfeel, a medium-long aftertaste and flavours described as fruity and nutty,” Dr Williams said.
“It is this sort of information that will allow us to inform consumers that Australia is a sophisticated and established coffee producer with enormous potential based on the unique characteristics of the region where that coffee is grown and produced.”
Terroir (translated as ‘taste of place’) refers to the environmental, varietal and agricultural factors that inform sensory experience. While the term is normally associated with wine and provides competitive advantages for high-quality wine producers, this research shows terroir equally applies to the coffee industry.
AgriFutures Australia and Southern Cross University produced the Defining terroir of Australian coffee to increase demand and investment report that summarises an investigation into coffee terroir, especially the terroir of Australian-grown coffee.
More than 100 Australian-grown single-origin green beans from 28 farms were analysed, along with an additional 50 international single-origin green beans. The green beans were roasted using a fixed roast profile to ensure equal treatment and then tasted by 15 coffee panels across Australia. The panellists included coffee growers, green bean buyers, importers, roasters, baristas, trainers and coffee judges. These coffees were also analysed chemically to provide a unique fingerprint.
“The coffees were de-identified and given to 138 panellists to taste at our coffee-tasting panels. We confirmed that Australian-grown coffee is sweeter, nuttier and fruitier in flavour. This pleasant terroir is probably due to the cooler temperature in our coffee-producing areas,” said Dr Ben Liu of Southern Cross University, the project’s principal investigator.
The researchers collected thousands of coffee descriptions from the cupping panels as well as coffee literature. A total of 679 unique sensory terms identified for acidity, mouthfeel, and aftertaste were distilled into a total of 95 for acidity, mouthfeel, aftertaste, and an overall grouping for shared terms. The reduced terms were arranged onto a coffee character wheel organised from broad to specific. The created character wheel provides a concise list of terms for coffee cuppers to assess acidity, mouthfeel, and aftertaste.
The University’s Coffee Character Wheel is unique. It expands on the original Coffee Taster's Flavor Wheel by including previously missing elements: acidity, mouthfeel and aftertaste.
“For coffee aroma and flavour, we standardise to the well-known Coffee Taster's Flavor Wheel. However, we also identified many coffee descriptions for Australian-grown coffee beans related to coffee acidity, mouthfeel and aftertaste. These descriptions have not been widely discussed in the literature,” Dr Liu said.
“We believe coffee is more than flavour. The acidity, mouthfeel, and aftertaste are also essential characteristics of coffee. We summarised these descriptions and created the world-first Coffee Character Wheel.”
Learn more: read the Getting to know your morning coffee a whole lot more fact sheet.
Just about one percent of the coffee that's drunk in Australia is actually locally grown. Australians love to drink coffee and especially fond of high quality coffee. Even though Australia is a huge continent there's only very few pockets that are suitable to grow. Coffee is very finicky, it doesn't like frost at all, it likes rich soils so a lot of areas are not suitable for coffee or they're competing with other crops so the few pockets where we do grow coffee is here in Northern New South Wales and up in the Atherton tablelands in Northern Queensland.
The variety they're using at the moment is very tall and very leggy when they decided on it about 20 years back it was the most productive and high quality variety but unfortunately it just never stopped growing so what the industry is looking for is a new variety that will say at a state a semi-dwarf state of around two metres which allows continuous machine harvesting without having to prune regularly.
What we're trying to achieve is to find a variety that's better suited than what's typically grown in this region. We're getting funded from Agrifutures from the Emerging Industries portfolio so their goal would be to have coffee 10 million gross value every year in five years, that can only be achieved if we do find a new variety that can replace the old variety.
We're trying to produce a good coffee cherry with the good beans in there.
From the coffee cherry to a cup of coffee there are still lots of processing that needs to be done and for example there's different post-harvest processing and maybe it requires different drying, different fermentation process. We also want to find the scientific evidence behind a good cup of coffee. There may be a different variety of coffee can be grown in Australia and each variety could actually have a different flavour characteristic. For example some coffee is very sour, some coffee may be very fruity. What we are doing here is trying to standardise the terminology to describe a cup of coffee. So we can find 50,000 different chemical markers in a cup of coffee and what we're trying to do is trying to link this sensory data that comes from coffee tasting panels to these 50,000 chemical markers and so later we can actually reproduce the same cup of coffee with the same flavour. As we can produce a good glass of wine in Australia I believe we can also produce a good cup of coffee.
The Australian coffee growing industry is long established. Today it consists of about 50 growers split between North Queensland, south-eastern Queensland and northern NSW, who have successfully created a distinct and high-quality product that services small domestic, tourist and specialist export markets.
“Producing clear flavour profiles, depending on where and how Australian coffee beans are grown, will assist coffee producers in defining and communicating the unique characteristics and flavours of their coffee,” said AgriFutures Australia, Senior Manager Emerging Industries, Dr Olivia Reynolds.
“Importantly, consumers can start to identify their preferences depending on where that coffee is produced, much in the same way as wine.
“We believe this is a really important step forward globally. But in particular for an emerging coffee industry in Australia that will reduce our reliance on imports and give consumers an opportunity to support home grown Aussie produce and its unique terroir, and what better way than through a locally produced flat white.”