Back on the Roaster...
The first roast struggles.
How do you efficiently warm up a coffee roaster?
We installed Cropster roasting software around 6 months after we initially got started with the roasting business, and according to today’s roast schedule, we have completed 21,805 individual batches to date. I have roasted a large majority of these batches and reading that figure, you would think I would know how to warm up the machine in an efficient manner, well it’s not as straightforward as you would think.
The trend for the first two batches has always seen the coffee coming in too hot. Almost 10-15 degrees higher in the turning point than the logged profile. This leaves me wondering if I have overdone the warm-up? I am not 100% sure of this as the inlet temperature probe reads way under temperature from when that coffee was originally profiled. Things do tend to settle around the third or fourth batch which leads me to believe that the environment in the drum has stabilised and is pretty much replicating similar environmental conditions.
Could the drum be the culprit?
We have no readings of actual drum temperature and all that the probes are really doing is measuring hot air. I have started thinking that maybe the drum is over-energised and a large amount of the stored energy from the long warm up is being released into the first batches. I could be way off here though. The interesting thing is that the inlet temperature never really strays from the profile once the third batch is dropped in and peaks out at around 290° on almost every subsequent roast. This would suggest that some sort of environment equalisation is taking place.
A few tests we are currently undertaking are:
Less time spent under warm-up conditions.
Lower warm-up temperature.
Only roasting the same coffee for the first two roasts.
Re-profiling the coffees and logging them as the first batch of the day. To be cupped and determined if this is the way to go.
Accept that you will never be able to understand what is going on.
Tryin not to roast decaf.
I often wonder if anyone else experiences this trend?
Happy Brewing
Burts X