Malted barley, of course.
Right.
Right, there are taxes, tariffs, etc. that depend on alcohol content, so they have to alter the recipe.
Indeed.
I have been trying to track down the source of the cardboard taste of foreign beers produced for consumption in the US. I am now speculating that the source may actually be something called "caustic acid," which is extensively used in US mass-production to clean the equipment and keep bacteria out. This stuff is absolutely wonderful for destroying bacteria, or any other living things for that matter, but what about the residual taste it leaves? This might be a complicated effect, and have to do with long-term interaction of caustic acid with the metal surfaces in a way that is not well-understood. What do people use besides caustic acid? Well, at micro-breweries bleach is often used as an alternative. Certainly, bleach can taste awful too (I've experienced this at some brewcos), but perhaps it is more readily rinsed off, and has no detrimental long-term effect on the metal surfaces?
Hard to say...I'm interested in what other's might have to say on this issue. My thoughts are only speculative...but I would like to find the source of the cardboard aftertaste. For a great example of this, try Asahi dry brewed under constract at the Anheuser-Busch brewery in LA.
Cheers! John