Hi Gary, Thanks for sharing your 1kg results. The largest size I have done on my KKTO is 800g. That ended up being a 19 minute roast, but did not reach second crack. I was roasting for plunger. No fire blanket used. My usual roast size is 650 to 700g, and the times are first crack at around 13.5 to 14 minutes, and second crack at around 18 to 18.5 minutes. I am roasting blends, and have not tried larger amounts yet, as the yield fits perfectly into two bags. I have experimented with burping, but find there is no need, as the roast progresses nicely. I am currently using up all of my beans, so each blend differs in some way. More experiments will be conducted when I get some new beans. I believe my KKTO can handle 1kg roasts with ease. My intention is to use the same blend, and roast 700g, 800g, 900g and 1kg. The times will be noted, and the roast stopped on second crack, or just a few seconds into it. For these weights, burping would probably stall the roast, so my intention is to just observe and record. The main difference will be the ramp time to first crack. The larger the weight, the longer the time to first crack. The time between first and second should be in the four or five minute vicinity. Only by letting the roasts settle and extensive tasting, can an analysis be made of which roast profile results in the best result in the cup. From past experience, I believe the longer roasts will be smooth and mellow with lots of chocolate. I don't mind this result, but enjoy some fruitiness with caramel and toffee sweetness. I think my sweet spot will be in the 700-900g range. If the beans you are using are from CS, then the results for your SO are similar in the cup to what I have found in the past. Smooth and mellow, good for a base, but requires the addition of other origins to achieve balance in the cup. As a SO espresso, rather bland, given the current choice of beans available elsewhere, albeit at a higher price. The KKTO is great for pre roast blending, and the practice of a five minute pre roast "drying stage" at the lowest temp setting, helps ensure a nice even roast. I still have a lot of testing to do with SO's on the KKTO. I find the Baby roaster produced better results for Yemen, with more fruit and berry flavours dominant, but as stated, I am still experimenting. I have had great results with Indonesian beans, but am still searching for the one that will yield body and sweetness without too much earthiness and spice. In the baby roaster these "notes" were too dominant for my liking. Overall, an excellent roasting platform. My goal is to learn all the quirks of the roaster (ideal batch size, ramp times etc), and then fine tune my blend. I think the Turbo Ovens are a perfect heat source for convection roasting, and a sweet, clean cup is achievable. I would be interested in the results in the cup from a heat gun source, and how much difference there is from the TO.
