Spot the green coffee defects!

[Dieter01]

In Ken's thread Fullsack posted this picture of bad quality beans:




Especially that one bean in the lower right quartile with a circular, brown dimple in it. I've seen that several times. What is it?

Also, do you discard every bean that has been chipped or otherwise isn't whole? What about brown spots or "wrinkles"? Discard everything out of the ordinary?


What does one look for?

[cannonfodder]

I believe that is an insect bite. That is what you would call triage coffee, bits and pieces. If that came from a 5 pound bag, it is not too bad, if it came from a quarter pound it is not to good. It also depends on the coffee; Yemen comes from heirloom trees and produces some funky looking beans. However a bag full of pieces is not good, ugly is not necessarily bad.

[barry]

that's way better than triage.

you could roast those up and have something drinkable.

[Fullsack]

The SCAA sells a Green Coffee Defects Handbook that makes claims such as: Insect damage effect cup quality with a dirty, sour, moldy flavor. Broken, chipped or cut green coffee beans cause an earthy, dirty, sour, fermented flavor, etc.

http://www.scaa.org/shop/products_catalog.asp

[SL28ave]

That circular brown dimple looks like "Coffee Berry Disease" also known as Colletotrichum Coffeanum, a form of Anthracnose. Or Cercospora, a common leaf fungus that can penetrate coffee beans.

I'm not sure, though.

[Abdon]

My experience with Harrars is that culling the uglies (how's that for a technical term? ) cleans up the cup substantially. I even use a screen to filter out the tinys, which would roast darker than the rest.

How about the odd bean that refuse to roast? With some coffees, a few beans simply do not get with the program and end up significant lighter than the rest.

[Fullsack]

The above picture represents 12 grams of defects picked from a 225 gram batch, too many defects for my level of tolerance. If your home roast source is giving you this kind of junk, it may be time to find another supplier. Professional roasters, as a group, are probably better informed about what constitutes acceptable green coffee bean quality, so home roast only suppliers, may not be the best source. Shop around.