I like the taste of cold brew coffee but I prefer to drink it hot. A certain proportion in which I dilute the concentrate with boiling water gives me the best taste, but the temperature of drink gets too low (even when the concentrate is at room temperature, I imagine it will be even lower if the concentrate is refrigerated).
My concentrate is brewed in proportion 1:4 (coffee to water by mass). That's the highest concentration most recipes suggest. I also tried using finer grinds and increasing the extraction time (up to 30 hours).
One way to solve the problem would be to try proportions 1:3 and 1:2, but would I be wasting too much coffee this way?
Another way would be to heat the drink, but that's inconvenient in office.
I could try boiling down the concentrate, but I'm afraid this will affect the flavor.
Does anyone have other suggestions?