There are the purists who believe beer should be simple.
The Bavarian Purity of Law of 1516, the famous Reinheitsgebot, stated that beer could only be made with water, malt (malted barley or malted wheat) and hops. Louis Pasteur wouldn’t discover yeast for a few hundred years.
Some suggest the Reinheitsgebot was just designed to ensure nobles, who owned the barley fields, had a dedicated market for their crops. The less jaded believe the law actually was decreed to keep questionable-but-readily-available ingredients like roots, berries and animal products out of beer.
German brewers still generally abide by the law for domestic lagers, though less so for exports. But you can still see the phrase “brewed according to the Bavarian Purity Law” on some beers exported to North America.
Germany had a tightly controlled domestic market until 1987 when a court ruling decreed such control a trade barrier. This allowed non-Reinheitsgebot foreign beers into the country. Even today, there is passionate discourse arguing both for and against the Reinheitsgebot.
Many Canadian and American craft breweries have embraced the spirit of the Reinheitsgebot to honour brewing tradition and distinguish themselves from big brewing companies.
The macro-brewers have figured out how to make really cheap beer through extensive use of corn and rice. The problem with these adjuncts is that you lose all the beeriness of beer — which includes a nice foamy head, a beery mouth feel and colour, and the taste of malt.
So these macro-brewers use chemicals in their beer to approximate these attributes. They also severely reduce the hops and filter all the yeast out. Both hops and the presence of yeast in beer lead to a longer shelf life, forcing these macro-brewers to add preservatives.
The alcohol industry is a powerful lobbying force. In Canada, they have managed to avoid food labelling. According to the Canadian Food Inspection Agency, alcoholic beverages with more than 0.5 percent alcohol-by-volume are exempt from showing a Nutrition Facts table, unless they make nutritional claims or contain artificial sweeteners.
This can be a nightmare for someone with an allergy to figure out that, say, it’s the propylene glycol alginate anti-foaming agent in beer that is causing their recurring rash.
Even some traditional beers contain questionable additives. Newcastle Brown from England uses caramel colouring in their beer to give it that lovely burnt orange-brown hue. The word caramel is deceiving because it refers to the colour, not the flavour. In this case the caramel colour is created by reacting sugars with ammonia or sulphites under high pressure and temperatures.
This is one of the reasons I drink craft beers.
Many craftbrewers willingly list all the ingredients in their beers so I know that the most toxic ingredient in the beer is likely the alcohol itself.