Kaffelogic community

Like others here I'm very new to all this too, so I've been reading as much as I can find about roasting. Scott Rao suggests all the good roasts he has experienced seem to have a 'development' of between 20 to 25%. (Development is the ratio of time from first crack to roast end compared to whole roast time.. (If I remember correctly))

Looking at Craig's log and assuming first crack is underway at 210C (is that a reasonable assumption?); the development is close to 50%.

Would it make sense to go for a steeper gradient to reach the higher profile temperature in a shorter time?

Although, Scott Rao suggests the Rate of Rise should be falling after the first two minutes of roasting - that sort of prevents a steep temperature gradient. I'm unsure how these two conflicting 'requirements' can be met.

Any thoughts from the Gurus amongst us?

Re the achieving ~25% development time; I'd wondered about that so had considered making a profile with a steeper rate of rise.

I've also read that the RoR shouldn't go below zero as that stalls the roast...

These are good questions and you will find a lot more discussion on other forums devoted to coffee roasting.

Robert Hoos has had a quick look at the Kaffelogic and had the following observation about zero RoR. The Kaffelogic temperature probe is close to bean surface temperature, but is nevertheless influenced by air temperature as well. This means that when you get to very low RoR you have to take this into consideration. You should therefore not be afraid to see zero RoR in the Kaffelogic because the bean surface temperature will still be creeping up toward the air temperature. In long, dark roasts this may be necessary.

The Scott Rao principle of max 25% DTR may only apply to the style of roast that he considers ideal. That doesn't mean it has to apply to a roast where you take things well into second rack. It may be an impossibility for that kind of roast, or it may be that it continues to apply. We are all interested in the result of your experiments in this respect - for the time being we don't have any profiles that would achieve 25% DTR and still go into second crack.