I think a lot of us have been encouraged by the fantastic experience of the first roast. There's nothing quite like freshly roasted beans, even if they're not perfect.

Then reality catches up. It's easy to roast something better than cheap supermarket beans, simply by starting out with more premium greens. But to match the best roasters is something else completely. Doing so consistently is a whole lot more difficult than pulling espresso in my opinion - but the journey makes it worthwhile

Thanks for that! I can totally see going from adequate to good will be a journey. Good thing I don't get discouraged easily! All the initial bad roasts and current mediocre roasts are data points. I got the beans sampler from SM, so I have at least another 6+ lbs of learning to do.

On the grassy tastes, is my logic right? I've read that grassy taste can happen by roasting too fast, where there's a big gradient between the outside of the bean (brown) to the inside (green). I think my cause is the opposite, developing at too low a temp so that the interior of the bean never gets to a proper temp while the exterior browns. I'm basing this on the fact that my development times are about where SM says they should be or a bit longer, maybe 2 min for city (and these have been tasting very light) and 2:30 for a city+.

I also consistently get smoky flavors both in cupping and on pourovers. Can this be caused by bad roasting techniques? Or am I putting the beans in my sample jars too early? I'll usually let them cool in the Popper, rest on a baking sheet for maybe two hours, and then put them in silicone sealed gas jars. I'm thinking I need to air them out overnight.

mikelipino wrote:I also consistently get smoky flavors both in cupping and on pourovers. Can this be caused by bad roasting techniques? Or am I putting the beans in my sample jars too early? I'll usually let them cool in the Popper, rest on a baking sheet for maybe two hours, and then put them in silicone sealed gas jars. I'm thinking I need to air them out overnight.

You probably need to cool them faster than they do in the popper. Dump them in a collander and hold them to a ventilating fan. Try to get them cool enough so you can hold them in your hand in two minutes tops. As to letting them sit (aka oxidize), don't. Put them in a valve bag or sealed jar immediately. If you are cupping early, within 24 hours, let the ground coffee sit in their cups for up to an hour (if cupping straight out of the roaster) to degas (you'll know they have degassed and are ready to cup by the dry aroma being there strongly).

Thanks for the tip Jim! Looks like I'm doing another cupping after the next roast, Popper cooled vs externally cooled.

Yes, you should look into changing what happens before first crack. Hopefully someone experienced with air poppers can try to answer how and why, but perhaps you can glean some inspiration from Kaffelogic's profiles.

One thing though - if you're roasting light and experience grassy tastes, let the beans rest for a long time. It could take a whole month, but if you're lucky most or all of it can disappear. If you put SSP brew burrs in your DF64 that might also help you extract good flavor out of those kind of underdeveloped* roasts.

*development is really happening during the whole roast, not only during "development time".

In a similar popper machine the cooling is fast enough, 50 C in 90 seconds, measured on TC4 sensor, but also passing ASTM C1055 skin pain test (140F/60C for 5 seconds in hand)
Actually, is the fastest cooling of all three roasters I own, other cooling methods, using classic tray/fan solutions needs 3 minutes for such performance.

mikelipino wrote: I'm basing this on the fact that my development times are about where SM says they should be or a bit longer, maybe 2 min for city (and these have been tasting very light) and 2:30 for a city+.

I also consistently get smoky flavors both in cupping and on pourovers. Can this be caused by bad roasting techniques? Or am I putting the beans in my sample jars too early? I'll usually let them cool in the Popper, rest on a baking sheet for maybe two hours, and then put them in silicone sealed gas jars. I'm thinking I need to air them out overnight.

Some of the guys I split sacks with use popper styled roasters for sampling and EVERY SINGLE TIME give me bleck that is over-roasted. I had a couple Popper roasts that were "roasty" but now I'm using a long spoon as a trier and pulling the roast when the beans have moved to mostly smooth surface say 90-95% than 50/50 wrinkled. I can't say the timing offhand but I'm thinking 1:30 ish-1:45.

When I get those notes on my gas drum its some combination of too long from 1C to drop, or too high of a drop temp. Usually its too high a drop temp.

What is the weight loss of the roast, i.e. the ratio in/out ?
Usually this is a hint of the "doneness" degree, 14% for medium/omni, less than 12% for "rare" (brew), more than 16% for well done (espresso)

Development time is not a measure by itself alone, have to be correlated with the temperature rate of change.

Hi all, 1st time here. I bought a popper from SM and just finished roasting my pound of Antigua. I'll be pulling shots for flat whites exclusively. While I'm not new to coffee, I am brand new to roasting. What's a reasonable time to wait before using a roast ?

A few days will often be enough. But it depends on the roast.