Roasting Above 800g

I’ve been reading a lot of different material about roasting lately, and Scott Rao mentions in his book The Roaster’s Companion that the optimal batch size is 60-80% of a machine’s capacity. For those of you who have roasted more than 800g in a single roast, have you noticed a significant difference?

I’ve done several roasts above 800g with good results.

I’m not an expert though. I’ve just been drinking coffee for 45 plus years and have plenty of experience with bad coffee. The main caveat is to make sure you’ve increased the preheat/charge temp for the batch size. If you don’t, it will draw out the roast time significantly, especially if you are doing a dark roast.

That said, even the longer roasts were very good. Part of that is the nature of the darker roasts I suspect.

It is good to read many sources to get perspective. Again, not an expert or professional but my big picture view is that coffee has been roasted for centuries. The history is quite fascinating. There are a multitude of ways for roasting and preparing it. In this “third wave” of coffee, you get some very pointed and opinionated advice. Some of it is based on empiric science, some is not. Some is very helpful. Some is marginal. There are many excellent sources online. If you source beans from Sweet Maria’s you’ve probably seen their educational section.

The Bullet is very capable and responsive. Best advice is to try it for yourself. Experiment, have fun and see what you like. “Defects” for some are desirable traits for others.

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First off…not everything Rao states is fact. Second, he has probably never used a roaster using induction as a heat source.

I have roasted up to 984g using the Bullet, completing the roast in ~12 min. I have roasted 800+g numerous times completing the roast in 9-10 min.

There are Bullet owners who have roasted 1200g with no problem.

Maybe they should call the Bullet a 1200 or 1300 g roaster…just so people can apply Rao’s BS rule on roaster capacity to the Bullet.

My take on Rao’s book is a problem of scale- it’s hard to scale a 25 kg roast down to 0.8 kg with drum dimensional differences, heat retention differences from wall thickness, and thermal-source capacities that are worlds apart. His consulting interests aren’t directed toward the micro-scale roaster like a Bullet. We all manage to turn out some pretty good tasting coffee even though (in my case) the RoR curve looks like the GPS track of a 5 year old backing up my old F-350 truck while Rao’s sample curves are drawn by an illustrator using a French curve.

That said, my second time through Rao’s book was more helpful than the first since I stopped looking for specific instructions. I enjoyed the book and felt like I have some appreciation for what the big kids are doing. My best take-away had to do with humidity control of stored green beans (cutesy burlap sacks for greens without a moisture barrier are not welcome at my place).