More often than not, it has to do with the preparation more than the beans.
There’s more than one way to make iced coffee
As J.
Park Brannen of Counter Culture Coffee toldFood and Wine, there are actually three methods of making iced coffee.

Cold brew is the go-to for boutique breweries and is hugely popular at the moment.
The concentrated coffee is then diluted with cold water based on strength preference, resulting in a smoother taste.
It’s suggested this method brings out the flavors more than the others.

Ideally, you should be using four tablespoons of ground coffee for every six ounces of water.
you could use a pour-over cup or a French press to do so.
And always use fresh, filtered water.
