How to pick a loser: coffee bean defects

#1: Post by **keno** » January 7th, 2007, 9:47 pm

Hey everyone,

Anybody have any good advice or better still know of a website that shows some pictures of what to look for in finding bad beans? What are the different types of bad beans? Also, do you pick out bad beans before or after roasting?

I sometimes find really small beans that are way underroasted (they almost appear yellowish, though the rest of the roast is full city). I usually pick these out, thinking that they will detract from the roast. Good idea or no?

Thanks,
Ken

#2: Post by **another_jim** » January 7th, 2007, 10:29 pm

I couldn't find a pictorial on the common bean defects; but here are two pages that give verbal decriptions:
http://www.teaandcoffee.net/0206/coffee.htm
http://www.coffeeresearch.org/coffee/brazilclass.htm

That being said, specialty grade coffee, as sold over the internet by the reputable vendors, should not contain any major defects, e.g. stinkers or blacks. However a few can get through. Very light or dark beans at the end of the roast should be culled; these are a result of defects not visible in the green bean, typicallly beans from unripe or overripe cherries. The one exception is dry processed beans from Yemen or Ethiopia. These are from heirloom arabicas with enough genetic variation that perfectly good beans roast at different rates. In these beans, the color gradations, if not too extreme, are desirable.

January 8th, 2007, 11:00 am

Thanks Jim!

The underripe beans I've noticed are after roasting Ethiopian dry-processed Sidamo. So that's very helpful to know. I've noticed that some of the African varieties (particularly the dry processed) seem to have a lot more variation among the green beans than the wet processed coffees.

The links are also very helpful - just what I was looking for (minus the pictures).

Cheers,
Ken

#4: Post by **yakster** » April 13th, 2009, 2:21 am

Apologies for reviving a dead thread, but I was looking for the same thing (pictures of defects) since I seem to be finding a fair share of beans with dark spots and insect damage in my Yemen and Tanzanian PBs since I've been sorting before my roasts. Seems like a lot, but it works out to be about 0.3 oz out of 16 oz of greens.

Besides Google leading me here, I did find some pictures on the same Coffee Research Institute site Jim references here and some more pictures at Sweet Marias and a page on coffee defects with pictures at coffeeterms.com:

http://www.coffeeresearch.org/coffee/defects.htm

http://www.sweetmarias.com/defects_seed ... cture.html

http://www.coffeeterms.com/coffee-bean-defects.htm

-Chris (sorting Tanz)

#5: Post by HB » April 13th, 2009, 7:34 am

Thanks for taking the time to help pull the references together.

April 13th, 2009, 6:52 pm

though not a bean defect (but a sorting/packing defect), i got a small pebble in a recent bag of greens from SM (thank god it didn't go through my grinder!). just a head's up to be on the look out for foreign objects as well as defective beans or it might cost you a new set of burrs.

#7: Post by **IronBarista** » April 13th, 2009, 9:24 pm

I found a little rock in my coffee recently. It was after I roasted so I had to check the rest of the bag. that would have been a little pricey for new burrs.