I put the blame on Cory Doctorow.
It was through Homeland that I first tried Cold Brewing. - I did it really quick and dirty. Just wanted to try it out and grabbed the coffe grounds we usually use. Lucklily we had some awesome tea filter bags which I (ab)used and the did their job. But let's be honest, looking back now what I created was horrible. - Though it still tasted way better than the coffee you get from your 20 $ coffee maker.
I learned my lesson and got some fresh beans, hand-grinded them and started experimenting with what I call "adding a hot bloom", different time settings, jars and ratios. By now I am quite certain you want to know what I am talking about (unless you already looked it up :p) - and I won't dissapoint you:
Cold Brew is coffee. But unlike your normal every-day coffe it tastes awesome. (No offence here, this was true at least for me and everyone I got to try my cold brew). The main difference is that you do not apply hot, but cold water. Your steep-progress will take a lot longer than usual and you will need better beans (at least I needed them, because we normally get the cheapest coffee you can get without going blind after the first sip).
So here is how you do it: Grab something like a nut milk bag (or handy tea filters) and fill them with a medium grind of good quality dark roast. (I maybe will do some reviews on the beans I tested so far). I usually take about 130-180g per litre - depending on how strong I'd want it and what I am going to add to the mixture later on. Then add water to it, cold water - (guess why it's called cold brewing) and just sit it in the fridge for 12-24 Hours (I got best results with about 16, and you should close the jar air-tight for best results).
That's it, you're done ! For those who really want to go nuts, maybe add cocoa beans or some vanilla (pods preferably) for extra taste. "Hot bloom" is what I call it when you add a little hot water early on (covering about 3 cm at the bottom) and let it generate some flavor. I normally add cold water after a few secs, but a minute will do as well.
With different chemical procedures (less bitter substances, untasty acids and so on) you will get a beautiful coffe-concentrate. You can simply drink it like that, add milk and ice for iced coffee or add warm water to get your hot and steamy morning-grog.
I usually take a small flask with me everywhere and use it as a wake-up-shot to get my daily 20 hours of efficiency :D But be warned - This will dry you up, if you are going to drink it as is : This is concentrate and will dehydrate you almost immediatly - so make sure to drink enough afterwards !
Furthermore you should not overdo it, as enough coffein can easily kill you,- but you really gotta be mad to drink a 2l bottle of this liquid gold.
So long - Enjoy your very own magic bean juice !