Good Morning!
I’m not sure what’s going on as far as recommended resting times these days. My view is that two weeks is always enough, based on many thousands of brews and developing roast profiles for many hundreds of lots - there is maybe one caveat though, which I’ll mention later.
Around four, maybe five years ago, we extended our testing period from one week to two weeks for each new profile. That’s because we were finding that in a minority of test profiles - there were still signs of ‘freshness’ in the coffee at one week. This tends to take two forms. Firstly, erratic extraction behaviour. Secondly, a couple of sensory things - a ‘flatness’ - as though the different flavours in the coffee are compressed together somehow and difficult to differentiate and/or a note in the finish that tastes very similar to roastiness.
In the first week, we almost always see one or the other (i.e. the sensory aspects, or the erratic brewing results).
If the profile is good, we’ll see the ‘roasty’ note disappear around day 5-10 in I’d say 85% of cases - and by day 14, in the rest. I don’t recall a single instance of ‘freshness’ taking longer than 14 days to resolve. There maybe very slight changes after 14 days, but we’re talking close to imperceptible to most people - and well within the range of what we could expect from normal variability in brewing results.
As the pseudo-roasty note disappears the coffee also ‘opens up’ and the roast becomes easier to evaluate, brewing behaviour becomes more consistent and sensory notes get easier to discern.
So, we have this two week testing cycle. If the roasty note and ‘compressed’ flavour profile are present beyond day 14, then the coffee almost always ends up being over-developed and we start the profiling cycle again.
The caveat I mentioned at the beginning? - most of what I know is based on using a traditional Probat drum roaster.
Having said that, we are in the process of getting a new machine, so this is something that I have looked into and I haven’t heard or seen anything that makes me think that a different style of roaster would be any different.