The Beer Lao factory is now offering tours to the general public.
They are currently finishing up an expansion project, but will reopen to public tours starting the end of October (that's the current schedule anyway). I was there today and saw a sign that said they will do public tours Monday through Friday from 9:00 am to 5:30 pm.
To schedule a tour, call 021-812-253 (if calling from a landline, you can drop the 021).
I don't know everything that is included in the regular tour, but was told that you get to see the brewhouse and bottling plant, and they probably throw in a free beer or two. I also don't know whether it is free or costs a nominal fee.
But hey, it's a tour of the Beer Lao factory, so it's likely worth the few dollars it may cost to visit.

Is this in Vientiane? Would you happen to have the address? I've toured many a brewery and wouldn't mind seeing this!

Its about 12 miles (km?) towards the friendship bridge. Its free and they give you a free beer , can buy glasses , shirts and all sorts of beer Lao promo gear. Not very exciting but it is the promised land for the beer Lao fan :-)

Yes, it's in Vientiane.
The brewery is about 14 KM from Vientiane on the Tha Deua Road towards the Friendship bridge. So someone could go to Buddha Park in the morning and stop by the brewery for a visit on the way back to Vientiane.
Or just head out and back. The road is currently under construction, but it is in pretty good shape.
I've been to the brewery twice now, first in January and again today. It is a great visit.

I like Beer Lao stickers but what I really want is a "Number 1" hat . where is the Number 1 factory and can you visit ?