Green Coffee Beans - Beans - Coffee Forum

Green coffee beans can have "defects" which can harm the result in the coffee cup.  You can tell a great deal about the processing conditions of a coffee by looking at the appearance of the green coffee, touching it and smelling it.  Although cupping is the definitive way to check for problems, the green coffee appearance is a good prognostic tool.

1.  The green beans should be of nearly equal size, be similarly shaped, and have a similar color.  The more even the coffee the more easy and even the roasting process.  Very uneven coloring hints toward drying problems, whereas uneven shapes may indicate a mixing of different coffees and qualities…

1.  Washed Arabica coffees should be even and bright.  The green coffee beans should not have an uneven or dull color.  If they do, it is likely have been dried or processed incorrectly.  If the green beans look faded, the cup quality will be faded.

2. Improper drying on patios or in mechanical dryers can usually be observed visually.  Rapid drying in mechanical dryers results in dull or brown coffees.  Beans that are mottled (or quakers when roasted) result when the coffee is dried too quickly, spread too thin on the patios, or not rotated as frequently as recommended. If the temperature used on the dryers is over 42°C you can expect a dull or baked cup.

3.  If coffee pulp is present in the tanks during processing it can result in brownish tinges on the green beans.  This is also indicative of harvesting over-ripe cherries.

4.  Natural (dry) processed coffees will often be covered in brown silverskin which has attached itself to the bean.  In Brazil they call this a fox bean and it is not considered a defect.  Novice classifiers might expect this type of bean to be a defect, but if you can remove a portion of the silver-skin by rubbing on the black sorting mat it is not considered a defect.  Green (under ripe) coffee also has a silver-skin attached to it, but this cannot be removed by simple rubbing.  In a washed coffee, fox beans may indicate sour, fruity, or Rio tastes.  This should be confirmed in the cup and not visually.

5.  Do the coffee beans have a little pink skin covering them or inside the crack of the bean?  In some areas this is a serious defect which most people do not consider to be a defect.  Since it is not a part of the green coffee classification, these beans could be passed on to the buyer as specialty grade.  These beans should be separated and cupped to determine if the defect is serious.

6.  If the coffee beans are whitish or faded around the edges then  this is likely a result of insufficient drying or storage in humid conditions.  The cup will be bland and ordinary.  These white marks are also observed in coffee that has not been dried evenly.  The part of the bean that has a whitish tone has higher moisture than the other parts of the bean.  Whitish or discolored beans can also result from oxidation, contact with the earth, or polluted waters.

7. Smell the green coffee beans. Ferment and smoke damage can be easily detected at this point, whereas they might be more subtle when roasted.

8. Pick up the green beans. How do they feel? If they feel glass-like and fragile they have been over dried or dried at too high of a temperature. If they are pliable they have not been dried sufficiently and should be rejected since mold growth at this point is unavoidable.

Green Coffee 800

thanks for giving the information about green beans.. this is very useful as a green beans business.