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  • QA 196
    Question:
    Do small green coffee particles affect cup taste?
    Background:
    What is the impact of using small green coffee particles on cup taste?
    Asked by:
    Intern - India
    Answer:

    Broken beans etc. are suggestive of unfavourable field conditions and/or incorrectly set milling equipment. In taste terms this means a lack of body, flavour and acidity, resulting in what is usually called a 'common' cup. *

    However, this is not to say there is no use or no market for what we shall hereafter call 'broken beans'.  The main objection to broken beans is that they should not be found in whole bean coffee. They roast more quickly than do whole beans (causing problems for the roasting process) and they depress the final quality of the roasted coffee. This is the reason coffee mills use both density and pneumatic separators to remove most if not all broken beans, shells and other pieces from whole bean grade coffees. For more on this see Chapter 11 of the Guide - Coffee Quality, particularly topics 11.05.06 through 09.

    Broken beans are caused by unfavourable field conditions, particularly drought and stress which tends to result in shrivelled and light beans that easily break up during the milling process. Picking of immature cherry and insect damage are other potential causes, as is over-drying during processing.  Improperly set milling equipment, particularly the hulling section, can cause otherwise whole beans to crack and break.

    However, there are also genetic aberrations that cause improper development and, therefore, broken beans. For example, three beans in a single cherry will result in three small wedge shaped beans that usually also end up in the broken beans section. Other examples include elephant beans: these are abnormally shaped beans and mostly break up during milling.

    Nevertheless, apart from very small bits, 'broken beans' do have a market but their use is restricted. They are difficult to roast, the weight loss is higher and the cup quality of the end product usually is mediocre. The decision whether to use them or not therefore depends on the end result that is required. For some users this obviously includes price...

    From a technical perspective then clean cupping broken beans, free from serious defects and/or impurities, have their uses. However, one should understand the challenges such coffees represent, and appreciate what they can and cannot be used for.

    One should also note that the global tendency is to reduce the amount of lower quality coffee entering the market. This suggests that the export market for broken beans must be shrinking and over time other uses will have to be found. For more on this please see topic 12.02 of the Guide that deals with the International Coffee Organization's Minimum Export Standards - also at www.ico.org.

    * We assume here you are not referring to the very small and light 'bits' that are a by-product of coffee milling and that, usually, are considered waste.

    Posted 14 July 2008

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