As 1st crack subsides, the coffee will slowly cease to pop, the smoke will all but completely subside and the only thing you will hear is the swishing of the coffee in the drum. At this point the coffee is still very hard and may be considered if you prefer a light roast. The coffee is still semi-green and may have a stronger grassy flavors. We will keep going a bit for this roast in this guide. Feel free to experiment with these early roast flavors.
Lets monitor our temperature and ride it out. We still should be 10 to 25 degrees below our initial temp depending upon the green load. (see above).
In our 2Lb example in the 4Lb drum, we are looking for 2nd crack to occur at around 14 minutes. As we approach second crack, the coffee will increase in temperature automatically without you raising the heat. Not a lot but it will slowly begin to creep up. Maintain your temperature and start watching for the white smoke again.
This is the final release of moisture and oils. We should start seeing the smoke again, a minute or two before the second crack actually starts.
2nd crack sounds more like rice crispies, having a higher frequency of a pop than 1st. The smoke is also thicker and heavier. In the same fashion we should start seeing smoke by say, 12 or 13 minutes. If we are seeing no smoke by say 13:30, we know that we are not anywhere close to 2nd. Lets push the heat up by 20 degrees just to shove our roast over the top and try to finish on time.
Lets go ahead and get your glove on as we’re about to pull the coffee, also turn on your cooling fan and get your cooling device setup.
The smoke thickens and you will slowly start to begin the higher pitch cracking. This is the physical fracturing of the bean itself. If you look around the edges of the bean, you will see these fine cracks at the end of the roast.
The cracks will begin to increase in frequency and the smoke will grow more intense to the point where the cracks are continuous and non-stop.
This is described as rolling second crack.
Now we need to examine here this very important moment. The minute before the start of 2nd and the minute after the start of 2nd are perhaps the most important moments of the roast and argurably where the roast will be a success or a failure.
Personally I will recommend that for a light roast you stop the roast an estimate 1 minute before 2nd and for a dark roast, 30 secs to 1 minute after the begin of 2nd.
All of the finishing of the coffee exists really in these last 2 minutes and during the cooling process.
In most cases, I will personally stop the roast right as soon as 2nd crack is established. When I am sure that the majority of the beans are starting to crack. This, for me represents the average balanced coffee. I’m sure I’ll get emails about that, like I said before, every roast, and roast master is different and prefers different things. In my opinion, 1 minute before 2nd crack, you will start to lose all of the grassy origin flavors, and even possibly some of the uniqueness of the coffee. At about rolling 2nd crack and forward, the coffee will noticeably begin to take on a darker, heavier, possibly more bitter and increasingly burned flavor (Sort of like Starbucks coffee).
I’ll recommend that you should almost never go past about 1 minute after 2nd crack as it results in a very dark coffee. Approaching 2-3 minutes post 2nd crack it is likely that the internal oils of the coffee will actually ignite and catch fire. Yep, that’s bad. It happens to just about everyone at least once!
So in this example, as soon as you can tell that most of the beans are cracking let’s stop the roast.