Interesting concept but I suspect there is a reason that sachets of beer concentrate didn't catch on during the 1970s, when the tooth rotting Soda Streams were on the go.
http://www.youtube.com/watch?v=oFeV0CbvHG8I think I will stick with a good Scottish Malt or perhaps some lightweight Tactical Nuclear Penguin if it wasn't so expensive. (The Scottish Government weren't to happy with Tactical Nuclear Penguin and tried to get it banned!)
www.youtube.com/watch?v=n4Tf3WCnMXQ