We get the same searches on the blog day after day regarding roast profiles and charge temperature.
There is no easy answer – but it all starts with density.
We measure the density of every coffee when it comes in so we have that information when it is time to sample roast for profile development.
Once you have a repeatable accurate system for measuring the density of the greens – you need to develop a chart that shows density relative to charge temperature from successful sample roasts.
From repeated sample roasts, logging and the cupping of the results and cross referencing with the density chart – your data will begin to make sense in relation to how you add or subtract heat etc.
This is why reliable and well thought out systems (density measurement, building the density chart, detailed and accurate roast logging, and cupping methodology) need to be in place before you start the process of profile development.
I cannot stress enough how using a complete and detailed roast log and stopwatch are key to definable and repeatable results. I have logged every roast that we have ever done and charted most of the sample roasting results.
Most of the time roasting is not as exciting as you might imagine.