Maybe I should have said it’s easier to get a consistent dark roast rather than a consistent lighter roast. When you’re roasting almost 5 million pounds of coffee a week out of 5-6 plants I’m sure getting a uniformly even roast is difficult. One thing I can say for Starbucks, their coffee has been the same over roasted crap regardless of where I am.No, they could get a good consistent medium roasting profile easily, with the equipment they have. They probably do. It is very capable and consistent high-volume equipment. But they are using cheap beans, and you definitely do not get to taste that coffee during the three week window after roasting, when it would actually taste good.
No, it's all roasted in Roasting Central, on huge fluid bed roasters, sealed up in vacuum bags, and when you buy a coffee or a bag, it's probably at least a half-year later. I have tried sealing the coffee I roast in vacuum bags, but it does not help much to increase longevity.
Even their “artisanal” roasts are roasted in Probat 120s that can roast 260lbs of beans at a time.