• QA 155
    Is the cup quality of large beans (like Maragogype or Kenya AA) always better?
    Is it really true that large coffee beans taste better? Like people say about Kenya AA or Maragogype for example?
    Asked by:
    Retail sector - Mexico

    Larger beans normally show better 'quality' but not necessarily always…

    To note first of all though that Maragogype is a variety of coffee whereas AA denotes a size grade of coffee.

    Maragogype is a botanical variety of arabica (a mutation of Typica) that naturally produces very large beans. It was first observed in Bahia, Brazil. The trees are very vigorous and produce exceptionally large beans but only in small amounts. It is found in a number of countries, including Mexico, Nicaragua, Honduras and Guatemala. Despite the quality premium often paid for this coffee (when full bodied in the cup) the small yield limits commercial production. Depending on local preferences the appreciation for the 'quality' of Maragogype can vary considerably from market to market.

    AA is simply a size grade. It is a large size bean that is separated from the total production by means of screening: the beans pass through screen 21 and are retained over screen 18 = 7.1 mm round hole*. AA size beans can be obtained from a number of arabica varieties and is commercially exported from East Africa, particularly Kenya and Tanzania. Of course top quality Kenya AA is known worldwide but the 'quality' does depend on the cup classification that can range from 'fine' down to even 'poor to fair'. Thus, there is excellent AA, there is good AA and then there is not so good AA…

    Quality depends on a number of factors. The most important are the inherent characteristics of the variety of the coffee itself and the production environment: climate, altitude and soils. These are factors beyond human control. However, standards of tree care, harvesting and post-harvest processing also impact (positively or negatively) on quality. If the human intervention here is inadequate, an inherently excellent coffee can turn out to be of mediocre or even poor quality in the cup… **

    With correct harvesting and processing the larger beans off a coffee tree normally produce better quality than the small ones. But, there is an important limitation here. A large but soft bean produces less 'quality' than does a large and solid bean. This not only applies to the cup quality but also to the roast - many large but soft beans tend to open up during roasting - some even fall apart.  Such beans contribute little to 'quality' and are best removed from the major grade by screening them out by adding a larger screen as in the example above: pass through 21. ***

    *     See topic 11.05.08 for more on screening and screen sizes, and topic 11.05.09 on bean density.

    **   Chapter 11 presents a wide review of coffee quality and processing. Chapter 12 deals with quality  control.

    *** We would also mention that very small beans, i.e. at the other end of the scale = below screen 14 or 5.6 mm for arabica and below screen 13 or 5.0 mm for robusta, can cause quality problems in that more defective and immature beans are likely to be present that can affect cup quality.

    Posted 12 June 2007

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