For some reason I haven't yet solved I had two consecutive roasts that were under-roasted. I took the beans from the first one pound roast and ran them through again at settings for half a pound. They definitely improved and now I wonder if there is a rule of thumb for re-roasting to salvage otherwise lost beans. Any guidance will be appreciated.

I searched for previous posts but found nothing on the subject so if there are posts regarding the matter I may be using the incorrect search terms.

The "rule of thumb" is if you botch a roast, there's no salvaging it. But I can't back that claim with science, and if a re-roasted batch tastes fine to you, then by all means drink it up.

If you want a definitive answer, next time you botch a batch, try re-roasting it. Then roast the same coffee again without error, and blind cup the two side by side.

"Double roasting" is a technique that was once used in Switzerland to create very low acid roasts. The beans are roasted to the first crack, left to cool, then reroasted until you get a color you like (no more cracks). I've never tried doing this, but I had the coffee when I was a kid (sort of like toddy brewed coffee). It creates a gorgeous translucent bean, so if you want to display roasted beans, this is the way to get them really pretty.

People on alt.coffee reported trying it, and it works. It might even work if the roast went further than first crack. However, the only reference I can find now is in Coffeesnobs

I reroasted some bolivian years ago when I first got involved with roasting. First time around they just went to 1st crack (barely). 2nd time I brought them to 2d. The beans came out very shiny, very oily. Not bad tasting, of what I can recall

Len

I used some in bread, some in chocolate icing and drank the rest - it was light but flavourful. I wouldn't do it intentionally. That's interesting about the Swiss technique. Thanks for the replies.

a few weeks ago i had a batch of nicaraguan limoncillo that was dumped by my hottop before 1C - don't ask...
following some encourageing advice from others over at tmc, i tried to roast them again - i had nothing to loose as i was ready to chuck them anyway. the result wasn't stellar but certainly drinkable. if you're reluctant to throw them, it's worth giving it a try i believe. if you don't like them you can still bin them after another round in the roaster...

How interesting, I was just coming here to write a post along these lines. I was roasting 1 lb in my Behmor (El Salvador Molino, I think) at p1 on 18:30, when the power gave out at 6 mins. I was super unhappy. About three hours I cam back to them, set it up for the same 18:30 thinking I'd only get 12 minutes or so before I had to turn it off. I went the full time, only 1 crack, but it was the best beans I've roasted - SUPER heavy mouth feel. My question since then has been: why? I've roasted probably 10 pounds of this bean, it's my favourite for the gloppy espressos I get out of it, but nothing compared to this day.

-phillip

I have also done this with the Behmor a couple of times. I've found you must end the second roast earlier than you normally would because the roast level will be greater due to the increased overall roast time.

phillip canuck wrote:How interesting, I was just coming here to write a post along these lines. I was roasting 1 lb in my Behmor (El Salvador Molino, I think) at p1 on 18:30, when the power gave out at 6 mins. I was super unhappy. About three hours I cam back to them, set it up for the same 18:30 thinking I'd only get 12 minutes or so before I had to turn it off. I went the full time, only 1 crack, but it was the best beans I've roasted - SUPER heavy mouth feel. My question since then has been: why? I've roasted probably 10 pounds of this bean, it's my favourite for the gloppy espressos I get out of it, but nothing compared to this day.

-phillip

My best guess is that you caramelized the heck out of the sugars. I don't get great body without roasting slow (10F/min) from 340-first. This give me faith, as I've got 5lbs of espresso base that the fuel ran out just before first. Maybe salvageable?

After three excellent years of roasting using a Behmor 1600 I needed a little support for this problem. Their support was exemplary and complemented the product perfectly. Things were back to great within hours of sending the first email. I recommend them without reservation.