A coffee cherry sample test should answer more than “can the machine sort it?” It should show which visible defects can be separated, how borderline cherries behave and what the result means for the processor’s actual quality standard.
Why a defect list is the starting point
Coffee processors do not all define a defective cherry in the same way. One plant may want to remove only clearly green cherries. Another may also separate overripe fruit, dark fruit or cherries with visible surface damage. If the sorting target is not agreed before testing, the result may look impressive but still be difficult to use in production.
WESORT begins by turning the customer’s quality concern into visible categories. This helps the processor understand what an AI coffee cherry sorter can evaluate and which issues require another inspection method.
Visible coffee cherry defects that may be evaluated
Depending on the variety, harvest condition and sample quality, a WESORT test may evaluate the following groups:
- Clearly green cherries: fruit that is visibly below the customer’s accepted ripeness range.
- Ripe cherries: cherries that should remain in the accepted product stream.
- Overripe cherries: fruit with a visibly different color or surface appearance.
- Dark or shriveled cherries: pieces whose external appearance differs clearly from the accepted standard.
- Visibly damaged cherries: cherries with obvious external damage that can be seen by the optical system.
- Borderline cherries: fruit between two categories, often requiring a separate review rule.
The test categories are not fixed for every coffee plant. They should be adjusted to the customer’s variety, commercial grade and downstream process.
What optical sorting can and cannot confirm
Optical sorting is based on visible surface information. It can evaluate color, shape, texture and obvious external appearance. It cannot automatically confirm internal fermentation, internal moisture, flavor or a defect hidden beneath the skin unless another inspection method is added.
This distinction protects the buyer from choosing a machine for the wrong reason. A sorter may remove a cherry with a visibly abnormal surface, but that does not mean the machine has measured every internal quality attribute.
How to prepare a useful coffee cherry sample
A small group of clean, easy examples is not enough for a serious machine decision. Prepare a mixed sample that reflects daily production and includes:
- Good cherries from the normal accepted stream.
- Clearly green cherries.
- Partially ripe or yellow-green cherries.
- Overripe or visibly abnormal cherries.
- Difficult cherries with dirt, shadows, surface marks or unusual shape.
If possible, label separate examples before mixing them. This allows the processor and WESORT engineers to review the test results against a known reference rather than relying only on visual impressions after the run.
How should the test result be judged?
The strongest result is not necessarily the one that rejects the largest amount of material. The processor should review both streams: how much target defect remains in the accepted cherries and how much good product enters the reject stream.
It is also useful to test a second pass. Some plants prefer a balanced first pass followed by re-sorting, while others need one-pass operation. The right choice depends on the value of the product, the available line space and the customer’s commercial standard.
Why WESORT recommends testing real cherries
Color differences can change with origin, variety, harvest date, lighting, surface moisture and storage condition. A result from another coffee producer should not be treated as a guarantee for a new sample.
WESORT uses the customer’s material to evaluate practical separability and discuss the appropriate coffee cherry sorting configuration. This gives the buyer a clearer basis for machine selection, program adjustment and line planning.
Conclusion
WESORT can evaluate visibly green, ripe, overripe, dark, shriveled, damaged and borderline coffee cherries in a sample test when the differences are visible and the sample represents real production. The test should always define the target defect, accepted standard, good-product loss and reject carry-over before the machine is judged.
Prepare representative samples and contact WESORT for a sample test and application review.
https://www.wesortcolorsorter.com/
Shenzhen Wesort Optoelectronics Co., Ltd.
