I'm using a Baratza Virtuoso grinder.

For a while now, I've been using the Toddy system. I follow the instructions in the manual, using a coarse grind (36 on the Virtuoso), and the recommended water ratio. However, I've never been that happy with the resulting flavor of the concentrate. The beans I typically use are either Stumptown (typically, Hair Bender) or Middle Fork Roasters http://www.middleforkroasters.com/ (typically, Troubador).

[As an aside, essentially, I'm trying to replicate at home the cold brew that Stumptown used to serve. I was told it by a barista their that the beans were Hair Bender; the flavor of that brew is better than any other I've tasted. I don't particularly like their current cold brew in the stubby.]

Cooks Illustrated recently posted another technique: http://www.americastestkitchenfeed.com/do-it-yourself/2011/08/how-to-make-cold-brew-coffee/. I tried this approach twice now, using a fine grind on the Virtuoso (1 and 10); I can't bring myself to use a 1:1 ground:water ratio as that just seems so uneconomical. With a 1:2 ratio of ground:water, I've been somewhat satisifed with the results - a bit better flavor than the Toddy, but not near the ideal of the Stumptown cold brew - but, again, it's an approach that seems to waste a lot of beans and is much more time intensive, because there's less resultant concentrate, so I have to do it daily. (I'm not necessarily opposed to doing it on a daily basis, if the flavors excellent, but the results so far haven't justified this approach.)

As a starting point, my goal is to maximize flavor from the resultant cold brew. Secondary goal would be to scale the resulting cold brew such that I can make enough concentrate to last more than a day while maintaining flavor.

So, any suggestions on how I can improve? Other methods? Different ratios?

Thanks!

I've tried a couple of different cold brewsteeping methods, including the toddy. It's just not the same. Whatever the science is behind it, I find that iced coffee that's made from hot brewed methods has a fuller, punchier flavor profile that I prefer.

Counter Culture recommends the Japanese pourover method (double strength brew, ice in the coffee pot, brewed coffee drips directly onto the ice), but I'm not consistent enough in my pourover technique to make it work all the time. A much more idiotproof setup, IMHO, is to brew double strength in a siphon and pour over ice-filled cup. Granted, it's more cleanup, but it's my go-to method for iced coffee.

You might want to try grinding a bit finer. I thought my cold brewed coffee was better when I tried grinding it just a bit finer than the quite course grind I tried at first. Might be worth a try anyway.