After experimenting with these five brewing methods, there was one clear takeaway: if you don't want your cold coffee to taste like a used Goodyear, you need to do more than just pour coffee over ice or throw it in the fridge. The two low-rent methods had terrible results, which is frightening considering the high quality of the beans involved. Lower-quality, pre-ground beans wouldn't stand a chance.
Of the three more-nuanced methods, each had their pros and cons. If you value a stronger cup, either of the overnight cold-brew methods is a better move than the flash-brewed Japanese style. We found that the traditional cold-brew method has subtler, more drinkable results, but hot bloom is the way to go if you're into more intense flavors.
Although both cold-brew methods made great coffee, the flash-brewed Japanese style resulted in a cup that most accurately emulated the characteristics that make hot coffee enjoyable. Since it's less batchable and has a shorter shelf life, this style takes a little more effort, but trust us, you're worth it.