While some like to experiment and explore beyond the tried and true, the Germans prefer to keep it pure.  Thus, in 1516 in the city of Ingolstadt, Duke Wilhelm IV of Bavaria enacted the Reinheitsgebot, or the German Beer Purity Law, to protect the purity of German beer through government regulation.   The Law dictated the ingredients for beer as well as its prices, and those who brewed impure beer were subject to uncompensated confiscation of their product.

The original Law stated that the only ingredients that could be used in beer were water, barley and hops.  At the time, Germans knew that the barley provided the color and some sugars while the hops balanced the brew with bitterness and served as a natural preservative.  Blind to the world of microorganisms, they did not yet know about yeast and its role to the fermentation process.  Before Louis Pasteur’s work with microorganisms in the 1800s, brewers typically transferred sediment from a previous fermentation to the next without understanding that the process provided the microorganisms necessary to perform fermentation.  In addition to the original three natural ingredients, the 1993 revision of the Purity Law specifies that yeast may be incorporated into bottom-fermented beer (lagers), and that different kinds of sugar and malt may be used for top-fermented beer (ales).

Throughout history, there have been various reasons for enacting and maintaining this Law:

• Brewers had a tendency to use cheap grain substitutes in beer, which resulted in an inconsistent and lower quality product.  The Law ushered in a new era of pride and enthusiasm for German beer.
• Bakers complained about competition with brewers for basic ingredients like wheat and rye, and consumers wanted to ensure that they they could buy affordable bread.  The wheat beers brewed today (hefeweizen) are not compliant with the original Reinheitsgebot, but are allowed under the 1993 revision.
• In 1871, Bavaria asserted the Reinheitsgebot as a precondition to German unification, to prevent competition from other regional brewers who used a broader selection of ingredients.  This protectionism led to the extinction of many German brewing traditions, including the North German spiced beers and cherry beers.  The broad reach of German beer protectionism ended in 1987, courtesy of a ruling by the European Court of Justice stating that beer imported into Germany does not have to abide by the Purity Law.

Modern German regulations allow for a broader range of ingredients (at least in ales), but those with a penchant for experimentation have searched for ways to escape their remaining purity shackles.  One team of scientists at the Technical University of Munich has focused on yeast as a “loophole” to even the Reinheinsgebot of 1516 (although I am sure that genetically modified ingredients also would have been verboten, had regulators known about them).  Their team created a process wherein they insert different genes into various strains of yeast to create substances like caffeine (stimulant) and limonene (lime flavor) during fermentation.  So far, their experiments have shown that their genetically modified yeast can grow in the relevant environment of hops, malts and water in sufficient amounts necessary for their experiments.  Further, they discovered that they may need to take steps to preserve the genome integrity of the yeast strains in their “SynBio Beer”: first brewing attempts revealed no difference in limonene content between the beer with genetically modified yeast and the control beer, perhaps due to loss of the plasmid that encodes limonene synthase.  Regardless of their experimental results, the scientists’ main goal is to “involve, interest and inspire people to reconsider preconceived ideas and encourage them to openly engage in a broad discussion weighing pros and cons of genetic engineering in foodstuff.”

In summary, some like it pure, some like to mix it up, and some like to circumvent the issue by applying scientific principles.  Like Venture Café, the world of beer caters to a diverse range of tastes and perspectives.