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  • QA 233
    Question:
    Would air-conditioning improve green coffee storage in hot climates?
    Background:
    What changes would green coffee undergo if stored in an air-conditioned warehouse in a hot country like Dubai?
    Asked by:
    Exporter - India
    Answer:

    It would, depending on the type of coffee and its condition when entering storage.

    As green coffee ages it undergoes chemical changes that affect the taste or quality, mostly negatively so. 'Mostly' because, for example, the well-known monsooning or deliberate ageing process that Indian Malabar coffees undergo creates a taste sensation that has its own enthusiasts and market!  But for conventional coffees, prolonged storage or storage in very hot conditions - particularly if coupled with humidity, results in loss of quality and especially so for washed arabica. *

    So, whereas storing green coffee in hot climates usually causes deterioration the impact varies first of all with the type of coffee because robusta fares better than arabica. The impact also varies depending on the original processing method in that natural or sun dried coffees fare better than washed coffees. Air-conditioning will slow the deterioration process but it will not eliminate it because air-conditioning does not create an inert atmosphere. It is only when the beans become totally inert that no chemical change will take place.

    If your intention is to store green coffee over prolonged periods (perhaps to sell it out slowly, bag by bag over time?) then we would first of all recommend to be extremely careful in terms of i) the moisture content at the time of shipment; ii) the shipping route (transhipment can cause delay and container heating/condensation); iii) the handling at discharge and transit to storage at destination (if on discharge containers are allowed to stand for days, container heating and condensation may result). In other words, the coffee may already have started deteriorating before entry into warehouse.

    Maintaining the quality of high quality or expensive coffee over time pre-occupies many and air-conditioning, to create dry and cool conditions, would help.

    However, depending on circumstances and the quantities to be stored it may be that vacuum packing (yes, of green coffee also!) and/or storage in gastight cocoons are also worth considering. The well-known Cup of Excellence project** has commenced exporting vacuum packed green coffee from participating countries to ensure the freshness and winning tastes are maintained. Leading producers in Brazil have been doing so for some time as well - see for example the Penta System used by Daterra Plantations by visiting http://www.daterracoffee.com.br/#/ids-home.

    We also suggest visiting http://www.mesoamerican.org/solutions_storage_systems.htm and  www.grainpro.com for information on experiences with gastight cocoons and other potential packaging options you might consider for larger quantities.

    *  Monsooning is the process of ageing Malabar coffee, first loose and then in bags, during the Southwest monsoon season when conditions are very humid. This causes the beans to turn golden yellow and results in a very different taste.
    ** www.cupofexcellence.org - Home of the international cupping competitions and Internet auctions for top quality coffees that were originated by the Gourmet Project for which the International Trade Centre (operators of www.thecoffeeguide.org) were the Project Agency.

    Posted 23 NOvember 2009

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