Is it necessary to sort beans after roasting?

Question

After roasting, the beans colour is usually uneven. Most of the beans have the desired roast, but some are burnt, and some have visibly lighter colours.

Some people sort every single bean after every roast. It is impressive work and result, but also tedious. I believe that is necessary for the look of the beans in a retail shop. Some other people sort just a little to remove really bad beans (i.e. burnt).

What are criteria / conditions to sort beans?

I wonder about taste: A tiny number of beans with different roast should not impact it, but I lack experience to know.

Answer 1

It will affect the flavor. Whether that's particularly noticeable depends on the bean, the roast you're going for, and how much variance there is in the roast. Whether it matters to you is a personal decision.

In my experience, over-roasted beans are worth removing from a light roast (I tend to prefer city roast at darkest), even if they're not actually burnt - the flavor of even a few dark beans will tend to overwhelm the more delicate flavors of a lighter roast.

That said, I use a popcorn popper; there tends to be a lot of variation in the results. If you have a better roasting setup, you can probably avoid a lot of the hassle.

Answer 2

Sorting done during the processing phase of coffee production (prior to roasting) is done in many places and can produce lots of coffee that look very different, but taste almost exactly the same. Peaberry beans may be sorted out (mostly by sight from what I understand) and sold as separate lots. Additionally size may be used and beans can be sorted with screens (slightly more automated) to produce lots that appear more consistent in size. While these things may affect appearance, they are not thought to affect taste (by most) and so all of these will likely be sold. However, during these same processes, any truly "bad" beans (moldy, unformed, etc) will probably be removed and discarded. If buyers see significant amounts of bad beans in a lot, it will be assumed that care was not taken in the processing of the coffee.

I roast at home and the only time I have ever "sorted" is if a bean or two from a previous batch was hidden in my drum and gets BBB'd (burnt beyond belief) in a second roasting process. Depending on roasting process, there is always a range of time that the beans get to certain points, they don't all hit first crack or second crack at the same time. If the beans are of sufficient quality and properly sorted after processing (at the source/origin) those ranges will be fairly narrow with not a lot of overlap. The machine I have now does a fairly good job or mixing the beans during roasting and the roasts I get from it are quite consistent. If I roast at a lower temperature longer, usually even more so.

To answer your question, the higher the quality of green beans and the better the roast technique, the less the need for sorting (if any). I can hardly see any reason for sorting beans for size/shape after the roasting process. Roasted coffee should be stored in opaque packaging, and any efforts to unify appearance would be nullified by proper storage. If there is so much variation in the roast that it needs sorting for flavor, I would suggest that time might be better spent refining the roasting process for consistency.