I prefer the natural sweet smoothness of a cold brew coffee made with coarsely ground beans. However, if it is inconvenient for you, or you only have fine preground coffee beans, go ahead. Try it. I'm all about experimenting and testing things out. You might even enjoy some of the bitter compounds in your iced coffee that generally comes with your hot cup of Joe. Here are a few suggestions: --> Go initially for a shorter, like 8-12 hours brew time, as it might result in a stronger flavor profile. --> A fine grind may produce more bitter flavors, so start with less coffee (¾ cup). You can always work your way up—or if already too strong, then add more water or milk of your choice. --> Maybe go for a lighter roast. --> Also, don't forget that with a finer grind, you'll need to use a fine filter like a paper coffee filter over a sieve or a French press maker that can strain preground coffee. --> Find more tips for using fine-ground coffee to make your own cold brew concentrate.