That's the beauty of the SC/TO; things happen in a relatively slow and even progression, and there's not much that can go wrong. You'll notice that with the larger bean mass it takes more to get it moving, but you'll also notice that once they do get going they like to keep going. With that in mind, try to anticipate 1st crack and avoid pouring too much heat into the beans. While you don't want to stall the roast, it'll be easier to detect the end of 1st and control what happens after.
OK, I think understood what you said but I'm not sure;
IT TAKES MORE TO GET IT MOVING? Physically moving or roasting?
Well, both. But I meant roasting. It's like there's some 'inertia' and the larger bean mass takes more energy to get the temps to rise.
ANTICIPATE 1ST CRACK? Anticipate silence or time it takes to get to 1st crack?
I watch temps, but the smell and the early-bird snaps signal the onset of 1st crack too.
POUR TOO MUCH HEAT INTO THE BEANS? Set the dial too high to start with or scorching the beans?
As you know, with the TO, the heat is either on or off. After letting the roast coast around 350F for a few minutes (a tip from BW, for caramelization of sugars and sweetness) I turn the heat on to head for 1st. But I like to modulate the heat as it nears and enters 1st, turning it off, then on, at least once to let some of the latent heat that built up in the beans on the way to 1st work its way out, so that the event of 1st crack is more controlled. As Glacier taught me years back, this is especially important with decafs.
STALL THE ROAST? Too low a temp to keep the roast going past 1st crack?
Too low a temp to keep 1st occuring. While the beans are being exothermic and giving off heat during 1st, they need to be fed enough heat to keep the process going, so that the crucial chemical changes in the bean continue.
DETECT THE END OF 1ST CRACK? Complete silence or the gradual slowing of 1st crack?
That is the unanswerable question. Beans vary so much; sometimes 1st ends very clearly and there's silence; and other times there's a minute or two of outliers. But I'd call 1st over when the majority of snaps is done, calling the time of the outliers part of the City+ segment.
Either way, the whole reason I try to keep from flying into 1st crack is so that 1st is a controlled event, and whatever the temp is when 1st is winding down can be maintained and slowly increased for a couple minutes. I feel there's some good flavor and body development happening in the 3 minutes after 1st if the temps are only slightly increased (maybe 4-7 degrees) without letting the roast characteristics of a FC or FC+ start encroaching on the origin characteristics of the beans.
