How to make cold brew concentrate? I enjoy the smooth taste produced by my Mizodashi cold brew jug, but prefer hot coffee.  Although I can dilute the cold brew with hot water, it gives me a pretty weak coffee (although great tasting).

So, the basic question is how can I create a concentrate with the smooth taste of cold brew that I can take into work and make my own coffee?
Like @Shiri said in comments above (and hopes that I'm not answer-sniping), most recipes for cold-brew are concentrates. Within reason, try brewing with a smaller amount of water! Compare guides like Kicking Horse, Stumptown, Blue Bottle.

In my experience (except for the problems that I've had with filtering) brewing a lower volume of water generates very similar results when diluted. Said the other way, brewing with a higher ratio of coffee :: water, then diluting, is my preferred way of brewing, storing, and consuming.

That said, do store in a neutral vessel that is easy to clean (my preference is a wide-mouth glass jar). Stored in the fridge, it will last several days (maybe a week) and still taste okay. In a plastic jug (or so) it might 1- start to obtain bad tastes from the container, and 2- infect the jug with stale coffee taste over time. Coffee oils (etc.) can be hard to remove especially when cold.

Some additional information is in related questions are about ratios and concentration and a concentration table in this answer.