Hi
I was reading a fascinating article in the New York Times on Beer in Vietnam. Sounds like they have a real lively micro brewing industry not to mention beers that are peculair to regions.
The one aspect that fascinated me was the story of the beer that lasts only for one day in Hanoi. Very popular apparently. Here's an extract:

No beer tour to Vietnam would be complete without heading to Hanoi to sample the ultimate people’s beer, bia hoi. Consumed in frightening quantities by everyone from Vietnam’s newly rich to its hard-working street vendors, bia hoi, sometimes called fresh beer but literally meaning gas beer, is an unpasteurized, unpreserved brew made before the sun rises, and often imbibed before the sun sets. All throughout the day, motorcycle deliverymen can be seen carting the grog around in everything from 100-liter drums to smaller plastic jugs. Much of it comes from three huge breweries, but scores of smaller mom-and-pop operations flourish as well.
Walking around Hanoi’s narrow, warrenlike streets, one sees bia hoi joints on just about every corner — with locals quaffing the low-alcohol brew (2 to 4 percent) as early as 8 a.m., after which time, some locals say, the peak flavors are already in decline. The décor at these places is a remarkably consistent mash-up of the children’s section of Ikea and the ultimate in street-life voyeurism: stands of shin-high plastic tables crammed right up to the curb and matched with semicircles of knee-high plastic chairs, all facing the road. Food venders are always nearby hawking the perfect complement to a tipsy evening: grilled meats, dried squid, pork buns, noodles.
The best bia hoi places in Hanoi serve a crisp, cold beer with a clean taste suggesting rice and an almost subliminal whisper of something like hops. Daytime visits to these chatty, casual settings are a great way to strike up a conversation with a local resident. But at night, patrons at many of the locals-oriented spots may be too consumed with their conversations to notice a wandering tourist.