First crack seems to last a very long time on my roasts — starting sometimes as soon as 7:00 minutes in and lasting 2-3 minutes or longer.
I’m wondering if adding a drying step will make first crack duration shorter? On my Gene Cafe roaster, I used to have a drying step. Set the temperature to 300F/~150C. This was low enough that the beans would not really get past the yellowing stage until I cranked the temperature up.
I think what you refer to as “drying” and by the way you describe it, seems similar to what some of us here do that is called “heat soak”. “heat soak” on the Bullet is to start at a high PH temp (e.g. 572 or 581 F for a 1kg batch) but the initial P setting is something in the P2 to P6 range, with a low F (so the hot air doesn’t get sucked out).
If that idea sounds similar to how you do drying on the Gene, then search these forums for “heat soak”.
Depending on your batch size, FC starting at 7 min is rather early. My 1kg batches FC starts around 9 mins (~395 to 402 F) lasting about 1.5 mins. But I think how “fresh” your beans are and the moisture content it is possible it could be longer.
I’ve noticed that some coffees have a longer first crack than others. If you’re seeing it on all your roasts and want to speed it up then you’ll need to approach first crack with more energy. The higher the energy that you enter first crack the lower the time until you reach second crack.
@blacklabs. Yeah, I think my unscientific idea of “drying” is probably the same as a heat soak. The way I think about it, you want to have the beans at a lower temperature for a while so they all reach the same temperature. Then you start cranking up the heat. In that way, I would expect to get a more uniform roast, with all of the beans in sync and hitting first crack at the same time.
I’m going to add an extra step to my recipe to keep the power lower when the beans are first charged. Then crank the power to 9 like I see in some of your recipes…
Well this latest recipe from aillio labs of the Mexico coffee is using a heat soak / extended dry phase, would be interesting to see what you find out after trying it.
link, just in case you don’t see this for a while and it is no longer in the recent posts:
Thanks @jimmybulletroaster. I’m looking over that recipe now. He does his preheat at P4. That’s interesting. It must take forever to preheat. And he’s going for 13.4% weight loss. Whenever I try a roast with weight loss that low, my flavors are always dull and flat. I seem to get better tasting coffee at around 15%.
I tried a few roasts today with heat soaks at P3 and P2. For me, I’ve been using a 260C preheat temp and a 600 g batch size. P3 heats too fast, and P2 is a little slow. My goal is to park it in the neighborhood of 150 for a while (maybe 5 minutes?), and then go to high power to get to first crack quickly. I think my next effort will be: drop to P2 after charge, then go to P3 around 158-160. Then at 162, I jump to P9.
I think I like this initial heat soak stage. But regrettably, first crack still goes on forever.
Only I might say about the weight loss, is that you cannot directly apply what happens on your roasts to how someone else’s goes. Heat has momentum, and how it is used throughout the roast can vary the supposed rules.
Are you trying to heat soak for that long? If I’m reading that correctly I’m not sure that’s going to benefit and you might lose momentum of your roast.
@blacklabs, thanks for that link to other thread. Maybe 5 minutes is too much. I’m going to look at @babs roasts. He says he does a heat soak for about a minute.
Just a sidenote. You cannot compare temperatures on the Gene and the Bullet. The Gene has only one probe, and that’s the one measuring the exhaust air. The bullet has a bean probe and the IBTS. Both measuring the temperature in the beans themselves. The bullet doesn’t have an exhaust air temperature probe. So, just forget about everything you’ve done on the Gene, and follow the good advice you’ve gotten from people here in this thread.