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Who is the report targeted at?
This research project was developed in conjunction with the Australian Coffee Growers Association from a need identified in their strategic plan. The findings are targeted at these growers.

Background
The Australian Coffee Industry has been expanding slowly over the last 10-15 years and more rapidly over the last 5 years. During the early industry development research concentrated on agronomic and production issues such as variety, irrigation and fertiliser requirements and weed control. As the industry has matured and many of the production issues have been resolved, the emphasis for research has changed focus to post harvest and processing issues.

As Australian production has increased and the “uniqueness” and “novelty” value in local markets has declined, growers are increasingly having to look for new markets. Very high quality coffee will be required to compete domestically with good quality imported coffees and on the highly competitive international market.

Understandably therefore growers are looking to further improve the quality of their coffee by fine tuning their processing systems. Improving the quality will not only make the coffee more competitive but will also lead to higher prices, which in turn will ensure industry viability and continued expansion.

Aims/Objectives
The project aims to determine the influence of various processing techniques on the green bean appearance and liquoring quality of Australian coffee and determine the best techniques to maximise quality. Through this project the Australian coffee growers have developed an understanding of how different processing equipment and techniques currently used on farms influences the liquoring quality. With this information growers may be able to modify their processing factories to raise the quality of their product and/or tailor their coffee for specific markets.

This research will directly benefit the Australian Coffee Growers. Their success will in turn benefit the rural communities in which they are located with employment opportunities and financial contributions. As well consumers are likely to benefit from improved quality of Australian Coffee.

Methods Used
An audit of current practices/techniques used by the Australian Industry to process coffee was conducted and some alternative processing techniques developed. Coffee samples were then collected from growers spread across the Australian production area and processed using several different techniques. Samples were then dried, hulled, polished, size graded, colour sorted and assessed for green bean appearance and then sent to a number of professional coffee tasters for evaluation of the liquor quality.

Results and Key Findings
The audit revealed that although all coffee in Australia is processed using the wet method there is quite a lot of variation in the way this is being achieved across the industry. Growers are using different pieces of equipment set up in different ways in their factories giving different processing techniques. From this audit seven different processing techniques were identified. To avoid the confounding effects of climate, variety and production techniques with the method of processing on the quality of the coffee, coffee from each individual farm was processed in several different ways and comparisons of quality only made within farms and not between the farms.

The results indicate that the method of processing does have a large impact on both the appearance of the green bean and the liquoring quality of the coffee. Green bean colour was best (green-blue, no silver skin and clean white centre cut) where the mucilage had been removed by fermentation in water. This was closely followed by samples in which the mucilage was removed mechanically. The poorest appearance was in the beans that were dried in the fruit (i.e. unpulped). These beans were pale yellow-straw colour with a lot of dark brown silver skin attached to the bean and centre cut. It is concluded that removing the pulp and mucilage and soaking, contribute to good bean colour and prevents the silver skin discolouring or adhering to the bean.

The liquoring quality evaluations indicate that samples pulped but not fermented (i.e. the mucilage is left on the parchment and dried) produced the best quality coffee with good acidity and body, sweet fruity flavours and smooth balanced pleasant cup. The partially fermented sample also scored well. The fully fermented coffee also scored well as long as the coffee was not over-fermented. The coffee with the poorest quality was from the beans that were dried in the fruit (i.e. with no pulping). This was attributed to the extended period of fermentation in the skin. These coffees were described as being defective, astringent, bitter, sour, over-fermented, rough, medicinal and winey. It is concluded that the presence or absence of the mucilage around the parchment and the amount of fermentation that takes place are the biggest contributors to coffee quality.

Implications for Relevant Stakeholders
Industry. With the information developed in this project growers are likely to modify their processing factories (where they can) to incorporate some of the findings. This is expected to lead to an overall improvement in the quality of Australian Coffee leading to higher prices and industry expansion. Consumers will also benefit from the improved quality.

Communities. Industry expansion in turn will help support rural communities in which coffee is grown by providing financial input and employment opportunities.
Policy Makers. Industry expansion will also contribute to the Australian economy with valuable export income and import substitution. Although this industry is small it does contribute to the economic diversity of the horticulture industry and regional employment opportunities.

Recommendations
The recommendations from this research are targeted at the Australian Coffee Growers who can use the findings to help them improve their quality.

Growers should trial processing some of their coffee as pulped naturals where the fruit is pulped but the mucilage is allowed to dry on the parchment. This processing technique consistently produced the best quality coffee. The fully fermented coffees also produced high quality coffees. This would require coffee to be treated in batches in the factory (with fermentation taking 12-24 hrs) but the improvement in quality suggests it is warranted Where fermentation is not used to remove the mucilage aquapulpers produced the next best quality coffee. The very poor quality achieved from red fruit dried down suggests that overmature samples (floating coffee from the factories) that contain even small amounts of red fruit will produce very poor quality if dry processed. A technique suggested (and practiced to some extent already) is to soak the over-mature/floating sample for long enough that it softens enabling it to pass through pulpers. This will pulp any red fruit in the sample allowing it to dry without fermenting greatly improving its quality.

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