For years, I thought cold brew was just watered-down coffee (like, why bother, right?). But then a friend made me try some homemade stuff, and it was actually super smooth and not bitter at all. What's a coffee belief you used to have that you don't anymore?
My cold brew sat in the fridge for 20 hours once. It turned out alright, but I much prefer the sharp taste of an iced pour-over. That method gives a brighter cup without all the waiting around. Cold brew always ends up tasting a bit flat to me.
Honestly if your cold brew tastes flat, you might be grinding the beans too coarse. A finer grind than you'd think can help pull out more of those brighter notes people miss.