Serious Eats - seriouseats.com

Good call on making the baker's dozen! I love Touriga Nacional, it has a very unique spiciness. St Amant and Barreto come to mind as two CA wineries that make Touriga.

Also, since many of these varieties are Iberian in origin, you can find a bunch of US wineries that produce them on the TAPAS web site: http://www.tapasociety.org/

I'd have to agree with the previous commenters, as much as I really love the notion (and by the way, I think it may be legal for producers in CA to do this - for example, some micro-breweries have refillable "growlers". But I suspect this is at the producer location only, not the retailer.)

A barrel weighs several hundred pounds full, so you would need a large enough truck to make that delivery safely, and a forklift at each end to move it - you either have to take the 'lift with you or there has to be one available. Kind of leaves the smaller retailers out of the picture...