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Coffee Seed Structure and Coffee Bean Defects

Images from Academic Texts and research of coffee development and defective coffee beans.

These images are from several sources as I recall, from the Illy Espresso book first edition and the compilation of technical papers by Jean Wintgens. I don’t have the original material in front of me so I am a bit unsure.

Yet these are valuable illustrations of the coffee plant, flower and fruit in growth stages. and some very cool micron electroscopy below of healthy versus unhealthy green coffee beans! The coffee seed structure at that level of magnification is fascinating! -T

Coffea Arabica - coffee plant root structure and early leaf formation
Coffea Arabica – coffee plant root structure and early leaf formation
Layers of the coffee fruit: endosperm (the green seed/bean), endocarp, mesocarp, exocarp.
Layers of the coffee fruit: endosperm (the green seed/bean), endocarp, mesocarp, exocarp.
The formation of the coffee flower and then the fruit
The formation of the coffee flower and then the fruit
Coffee cherry development. Stages of coffee fruit growth. The illustration at Stage F is pretty silly - anyone who farms coffee knows it never has that thickness of skin and pulp / mucilage surrounding the coffee cherry
Coffee cherry development. Stages of coffee fruit growth. The illustration at Stage F is pretty silly – anyone who farms coffee knows it never has that thickness of skin and pulp / mucilage surrounding the coffee cherry
Black beans and partial black beans. These occur due to fungal attack, and create a highly defective taste in the cup. In coffee grading the full black bean is the basis for scoring all other defects.
Black beans and partial black beans. These occur due to fungal attack, and create a highly defective taste in the cup. In coffee grading the full black bean is the basis for scoring all other defects.
Vinegar / Sour. Another example of overfermented coffee.
Vinegar / Sour. Another example of overfermented coffee.
Moldy-blotchy coffee that has undergone a secondary microbial attack. This can happen when drying is repeatedly interrupted by wet weather and the coffee isn't safeguarded.
Moldy-blotchy coffee that has undergone a secondary microbial attack. This can happen when drying is repeatedly interrupted by wet weather and the coffee isn’t safeguarded.
Sours, over-fermented coffee, left in fermentation too long. Sometimes they are caught in the pulper machinery, and get into the coffee batch due to poor cleaning and maintenance.
Sours, over-fermented coffee, left in fermentation too long. Sometimes they are caught in the pulper machinery, and get into the coffee batch due to poor cleaning and maintenance.
Floaters, formerly called sailors. Coffee without bean density that float in water.
Floaters, formerly called sailors. Coffee without bean density that float in water.
Moldy coffee beans, usually a storage damage issue.
Moldy coffee beans, usually a storage damage issue.
Transverse cut of a healthy, fully developed coffee seed/ green bean
Transverse cut of a healthy, fully developed coffee seed/ green bean
Cellular "compartment" structure of a healthy green coffee bean with "full" content of proteins, lipids, etc.
Cellular “compartment” structure of a healthy green coffee bean with “full” content of proteins, lipids, etc.
Closer view of cellular "compartment" structure of a healthy green coffee bean with "full" content of proteins, lipids, etc.
Closer view of cellular “compartment” structure of a healthy green coffee bean with “full” content of proteins, lipids, etc.
Underdeveloped, immature coffee bean, with insufficient cellular content
Underdeveloped, immature coffee bean, with insufficient cellular content
Closer view of the the black bean defect (microbial attack of the coffee bean) with destroyed cell content
Closer view of the the black bean defect (microbial attack of the coffee bean) with destroyed cell content
Black bean defect (microbial attack of the coffee bean) with destroyed cell content, under micron electroscopy
Black bean defect (microbial attack of the coffee bean) with destroyed cell content, under micron electroscopy

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    • 2 Responses

    1. I live in San Diego, and some of the coffe berries have no seed. Do you know what causes this? Thanks in advance

      Reply

      1. If you mean you have a plant with empty cherries, then I think that is failed fertilization when it has flowered, but not sure. Coffee self-pollinates but it can still fail and then the seed doesnt develop. I have seen it more in plants with physical issues, and more toward the ends of branches than near trunk – nutrition delivery?

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