Hello Everyone
I’d like to ask you about recipes. For example, if Rob Hoos’ recipe is for 150g, if I want to roast 300, 500, or 1kg of coffee beans, what variables should I adjust?
Depends what you’re trying to achieve but I would start with a higher charge temp and power.
I roast 200g often but have been experimenting with 350g and 500g recently. I noticed I have to implement fan towards the end of the roast for +350g batches.
The best way to figure out is through trial, I think. Start by matching end color of the beans, development percentage, and lastly first crack timing. Make a roast profile plan, execute, evaluate, and make single adjustments to variables.
Check the screenshot attached. It’s from the Aillio BulletR1V2 official manual:
Hope that helps.
Scaling a roast recipe usually is not as simple as doubling every setting. When you increase the batch size, the beans absorb more heat, airflow behaves differently, and milestones such as yellowing and first crack may occur later. You will often need to adjust preheat, starting power, the timing of power reductions, and fan changes rather than simply multiplying the original recipe.
A good approach is to treat the 150 g recipe as the intended shape of the roast—its milestone timing, declining RoR, and development—then make controlled adjustments for each larger batch size.
I developed a tool called RoastRecipeAdvisor that may help with this. It analyzes your Bullet roast history, batch size, bean, recipe, and results, then suggests adjustments for the next roast. It is especially useful when adapting a recipe to a different charge weight because it bases the guidance on how your own roaster actually responded rather than assuming that recipes scale linearly.
You could import the original recipe, roast a larger batch, and then use the completed roast to refine the next attempt.
Try it here: RoastRecipeAdvisor