This article picks up where the last one left off, so please take a look at the last post to get a bit of orientation concerning the rest of the discussion.  The first post covers the fact that changes in roasting technique played a role in the history of pilsner.  This post attempts to cover what happened when yeast, more specifically, lager yeast was discovered.

Lagering and the Discovery of Yeast

Lagering beer has a long history well before the actual discovery of yeast.  Making lager was a product of, if you wish to call it such, government intervention.  It was found out that brewing in the hotter months was often a precarious practice due to bacterial infection (although no one really knew it at the time).  Beer could not be produced with predictable results during certain warm months, so it was strictly forbidden.  Bad beer was serious business in German, even to the point of physical ramifications.  Therefore, plenty of beer was stored in cold caves (lager is the German word that means “to store”), which aided in it’s preservation…but no one knew why.  Two significant occurrences came about as a result: lager strains and smoother beer.

Meanwhile, purity law (Reinheitsgebot) was instituted to ensure that beer only contained water, hops, and barley (rye and wheat were forbidden to prevent competition with the baking industry).  And later the law was changed to include yeast.

As noted above, the aging period of the beer at cooler temps reduced the amount of harshness in the beer and prevented bacterial issues from occurring.  Even today, lagers are known for their exceptional smoothness.  Once again, historical necessity dictated future practice.  I can only imagine that the shifting from necessity to norm.  Very interesting!

Second, the first beers of the world were ales.  Ales are able to ferment and function at higher temps.  But what happens with the temps are cooler?  Well, biochemical process dictated that the yeasts strains that could survive at colder temps would be the primary yeast that also ferment the beer.  So, the ale yeasts would die at cooler temperatures, while the lager strains would, albeit slowly, flourish. Therefore, when the flocculated (dropped out of suspension) yeast would be used in the next batches of beer, it would be the lager yeast that survived the best.  As a result, the lager strain become more and more predominate and pure.  Now we are talking lager yeasts.  But yeast was still not well understood for a few hundred years.

Pasteur “discovered” yeast in 1857.  It’s notable that his wife continued his work after he suffered stroke.  But he set in motion a discovery of yeast as an organism and that added to the progress/progression that has brought about much of what we enjoy about beer today.  But I’m skipping ahead a bit because yeast was known and somewhat understood, from a functional perspective, previous to Pasteur’s bombshell.  At any rate, the real meaning for yeast in Pilsner was very much later than the existence of the lager strain (circa 1402).

It is purported that the first person to bring bottom fermenting (lager) yeast into the Czech republic itself was a Bavarian monk in 1840.  Aside from Bavarian beer being delicious, it is pretty far South, which made the travel fairly close.  However, using the word “smuggled” to describe the how the monk got the yeast to the Czech Republic is a telling word which points to the true danger associated taking the yeast elsewhere.  Maybe it is not incidental that a fire up North in Hamburg, which left 20,000 or so homeless and destroyed half the city, turned away the concerns of what was occurring in Bavaria.  So, safe passage was there but maintaining the yeast’s life was the new concern.  Fortunately, the yeast strain kept well and the brewers that received the yeast knew what they were doing, and the strain lived on and two years later the first “Pilsner” was born. The result of the yeast mixed with that really light grains was brilliant. But what could showcase the light, brilliant lager beer?

Glassware was needed to show the true brilliance of the beer…the subject of the next article.