I’m curious to see if anyone is interested in sharing what they have found is the best use for the fan.
On a recent trip to a coffee farm I was introduced to an experienced roaster, grader and producer. I made the most of the opportunity and asked all of the questions I could recall that have been tumbling around my head for the last couple of months. One of the main ones being what is the fan for and how/when should it be used?
In the name of honesty I am still grappling with his answer, and have yet to fully digest it, but this is what he said… more or less.
He explained that the fan removes pressure from the roast, and that depending on the situation, it is necesary to release pressure from the roasting chamber. This explanation was tied into a larger conversation about a specific farm that produces particularly small and dense beans that take a lot of heat upfront but then seem to develp too quickly after yellowing.
He continued on saying that you want enough pressure to break down the outside cellular structure of the bean, allowing the heat to penetrate deeper but you don’t want to let the heat over cook the outside leaving the inside under developed. Somehow the fan plays into this, it allows the inside to continued developing as you release the burden from the outside.
On another note he mentioned that you likely don’t want to blast your fan all at once, but rather ease into higher fan speeds. He mad an analogy about holding onto a rope while leaning back, how there is pressure on the rope and if it is released slowly you will have time to adjust your weight to stay balanced, however if the ropes tension is released all at once you will be jerked back and fall, meaning your roast will crash.
It’s incredible the amount of knowledge some people have amassed, and I feel particularly lucky to be able to meet such incredible people that are so willing to pass on what they know. I will be talking more on my experience in the future but for now I am curious to hear about what people on here think about the subject of using your fan during the roast.
Best Regards to all