Been roasting all my coffee since >10 years. My 3rd roaster is the Quest m3s. Always generating lots of chaff of course. Regardless of supplier or type of beans. Had to change supplier of the beans recently. I find the taste is not as good from this new supplier. Anyway, I noticed something new roasting these beans from my first roast a few weeks ago , no chaff was produced using beans from this supplier. Regardless of the origin or type of beans I use, all beans from this supplier behaves in the same way... No chaff, or very little at least. The outgoing filter on the outlet is usually filled after my session of 4 roasts. Now it's completely empty.

What could be the reason there is no chaff produced? I guess they have been stored in wrong conditions or they are very old. Anyone know about possible reasons?

There is of course a very small probability that something happened inside my roaster exactly at the same time as I switched bean supplier. Difficult to proof at this time.

Would be nice to know if there's a known reason for this to happen.

I wonder if the greens are old. What color is the green coffee? Really fresh green coffee has a bluish hue, which fades to green which is what you normally see, but even this will fade even further to more of a pale tan. This may be related to moisture as well.

that what Yakster said, I am unable to roast more than like 2 batches without cleaning chaff from the exhaust filter.

If you want to check we can roast the same bean at litle extra cost since we're both EU based, and compare notes...

OP hasn't been back since the post, but I'd suspect a wet hulled coffee was roasted. Very little chaff with that process in my experience.

Interesting thread. I've been roasting Sumatran Mandheling lately, almost no chaff. I know Sumatran coffees can be wet hulled. This one is supposedly naturally processed.

Indonesian mills tradtionally polish the chaff off beans as the final step; so that the roasts are chaff-less regardless of processing or age. Some greenies did the same thing with all beans they sold for a while, but it never took off. Maybe it just doesn't feel like roasting unless there's chaff flying around.

Thank you all for the feedback. I was expecting to get E-mail notices when someone replied, need to check my settings...

It's time to order more beans, so I did check if there were any replies in my thread.

Just checked my beans. In one bag the beans were more towards yellow, but the other more green. I have very small quantities left from the previous supplier, they look very much to have the same greenish color. So nothing special found just by looking at the beans.

I just sent a question to the supplier if he has some theory. If not, I guess to look for yet another source of green beans. There are very few here in Sweden. Many that sells green beans only sell small bags for "fun" at crazy prices.

Historically there has been perhaps one or two type of beans that haven't produced any chaff during all my years of roasting. But now i have the same behaviour for alla beans from one supplier, regardless of country of origin.

Thanks again for all feedback. I'll update this thread if I get some result in the future.