Wednesday, 28 March 2012

My First Solo Brew at The Bull

So Dan at The Bull recently gave me the opportunity to brew, on my own, a beer of my choosing. This has been the chance I have been waiting for. I have been a homebrewer for years, but I have up until now never been able to brew a beer that is served in a bar. Naturally I was nervous, as I didn't know the brew kit terribly well, and I felt as if my entire reputation as a brewer rested on this one brew. Obviously, was being a bit dramatic, but I take my beer very seriously.

The beer recipe that I settled on was a Scottish ale with a target alcohol content somewhere between 4.0% to 4.5% alcohol. Usually, I would be able to be a bit more precise in my predictions but not knowing what brewhouse efficiency I would have, I decided it was better to make a recipe that could handle some variability. I decided to make the color relatively dark and the bitterness levels very low, similar to what a historical Scottish ale would be. The reason why Scottish ales traditionally have low amounts of hops is that, first of all, the English were very late to adopt hops relative to the rest of Europe. In addition, once the English discovered how wonderful hops were, they were reluctant to export them to the Scots because, apparently, English and Scottish people don't get on very well. As a result, Scottish ales had very low levels of hops and often even used other ingredients such as heather as bittering or flavoring agents for their beers. Therefore, in order to stay historically accurate, my hop schedule would be to use a very modest amount of English Whitbread Golding hops for bittering and an equal amount of the same hops after the end of the boil for aroma. Historical Scottish ales probably would not have had much aroma hops, so I went back and forth on deciding if I should add them at all. In the end, I decided it would be a more balanced beer with them included.

Overall, I think the brew day went smoothly. Nothing disasterous happened (even though I had recently been having bad dreams about everything that could go wrong with this beer). The worst thing that happened was a small overflow on the hot liquor tank, but a little mopping fixed that. One thing that did go very much according to plan was the color of the beer. It is a deep red mahogony color that I think will be very beautiful once the beer is done. The gravity was also in the range I wanted, and if the fermentation goes as I expect the beer will be about 4.3%. Now all I have to do is wait. After all, the most important part of the beer making process is happening right now as I write.

As a final thought, just the fact that Dan has enough confidence in me to let me use his system to make a beer that he will actually serve to customers is something I am very proud of. If this beer turns out well, the day I try the first pint will certainly be one of the best days of my life.

Sunday, 18 March 2012

Mashing Enzymes Part 1: Starches

The entire brewing process involves enzymes. From before barley becomes malt, until after the beer is put into packaging, enzymes are constantly changing the chemical composition of beer. Even yeast, from a purely functional perspective can be thought of simply as bags of enzymes. What I want to focus on in this series are the main mashing enzymes of interest to brewers: alpha amylase and beta amylase. Why I believe this is so important is that many brewers (homebrewers and professional brewers alike) don't really understand how they work and why this gives them the blend of fermentable sugars and unfermentable dextrins that we call wort. The concept most brewers understand is the general rule that lower mashing temperatures lead to more fermentable wort, while higher tempuratures lead to a more dextrinous (less fermentable) wort. In a broad sense this is true, but it doesn't give brewers much of a base to trouble shoot what has gone right or wrong with their mash. There are, of course, other enzymes that play a roll in mash composition (proteases, beta-glucanase, limit dextrinase, etc.), but they are much less important. I will circle back on those later.

There will be four short segments in this series, starting with starches. By the end, I hope that anyone with interest will understand more about why mashing enzymes work as beautifully as they do. After all, without them beer would not be possible.  


In order to begin understanding how alpha and beta amylases work, it is imperative to first understand the substrates they work on. Just like there are two main mashing enzymes, there are also two starches in barley: amylose and amylopectin. These represent the energy reserves of the barley grain, and it is this energy that brewers ultimately need to harness to make beer. In a very basic sense, both amylose and amylopectin are just big bunches of glucose molecules linked together. Brewers want to pry apart those links of glucose molecules using enzymes, making them small enough for yeast to digest.

The simpler of the two main starches is amylose. Amylose is just a straight chain of glucose residues linked together and makes up 20-25% of the starch mass native to barley. Given enough beta amylase action (more on this later), amylose can almost completely be reduced to maltose, the main fermentable sugar in beer wort (also more on this later).

In this diagram of amylose, each of the circles represents a glucose molecule. In reality, amylose is a much longer chain of bonded glucose molecules, but this is sufficient to understand the general structure. Also, don't worry all that much about what the reducing end means just now, but take note that it is there. Later on it will become important in determining which direction enzyme action takes place.  
The much more complex and larger of the two native starches is amylopectin. This is a similar molecule to amylose making up about 75-80% of native starch. What makes amylopectin different from amylose is that it has many branches of glucose-linked chains. Amylopectin is, therefore, much larger and heavier than amylose. More or less, you can think of amylopectin as a big tree of amylose molecules. All of the glucose bonds on the branches are the same as amylose. Yet, because of the more complex structure of amylopectin near the branch points, it is the main contributor of dextrins (unfermentable sugars) in wort. It also relies more on the combined action of alpha and beta amylases to break it down into fermentable sugars than does amylose.

As with my representation of amylose, this one of amylopectin is very simplified and actual amylopectin molecules in barley are massive. 

Friday, 2 March 2012

Why Germany Brews Lager

It has always fascinated me why different parts of the world have developed their own unique brews. The UK has Real Ale, Belgium has Trappist beers, Latin America has Chicha, and Germany has lagers. I recently came across some information in an article written by Horst Dornbusch in The Oxford Companion to Beer that shed some light on why Germany in particular has such a tradition of lager brewing. Today, lager (mostly of the light pilsner type unfortunately) dominates the world market, and it was with German influence that this lager trend took root. Before I begin, I would like to say that if you talk to me personally, you would get the impression that I am not a big fan of lagers. This is for the most part true, only because the vast majority of lagers produced today are mass market, watery, flavorless rubbish. Some lagers produced in Germany, however, are amongst the best beers in the world, displaying other ingredients (malt and to a lesser extent with most German beers, hops) instead of a yeasty ester profile. Give Paulaner's Salvator Doppelbock a try and you will understand what I mean.

Surprisingly, the tradition of lager brewing grew out of a long period of bad beer in Bavaria, particularly in the summer months. Warmer temperatures promoted the growth of a host of different spoilage organisms that were largely dormant in the brews of the colder months of the year. Summer beers were often so bad that brewers would resort to using a number of products to mask the flavor including oxen bile, chicken blood, soot, tree bark, or even poisonous mushrooms (it really is a testament to how bad the beer was that oxen bile was preferable to the unadulterated beer). Of course, this was long before the discovery by Louis Pasture in the late 1800's that living organisms caused beer spoilage, so the powers that were did what they could to try and mitigate the issue. 

Over the course of a few centuries, there were multiple attempts to regulate the quality of beer. In 1156, the city of Augsburg issued the first decree on spoiled beer insisting that all the city's bad beer "shall be destroyed or distributed amongst the poor at no charge." This held citizens off for another two hundred years when in 1363 twelve members of the Munich city counsel were appointed to inspect the quality of the city's beer. Further, in 1420 Munich decreed that beer had to be aged for a minimum of eight days. In 1447, the precursor to the famous Reinheitsgebot was laid out saying that Bavarian beer would only consist of barley, water and hops (remember, the existence of yeast in beer was not yet discovered). And finally, in 1516 the Bavarian Duke Wilhelm IV extended the 1447 decree to cover his entire kingdom.

Those attempts at quality were all well and good, but they didn't have the intended effect, and summer beer often continued to be putrid. Although far less famous than the Reinheitsgebot, the legislation laid out by the Bavarian Duke Albrecht V in 1553 had far more significant ramifications for the beer world. Duke Albrecht V simply forbade the production of beer altogether between the Feast of Saint George (April 23) and Michaelmas (September 29). This did succeed in stemming the production of bad beer but, more importantly, it unintentionally led to the development of lager brewing. As production was halted in the warmer months of the year, ale yeasts were phased out and only the yeasts capable of fermenting at colder temperatures survived, eventually hybridizing to create a new species of yeast. Stronger beers brewed towards the end of the brewing months became known as March beers or Märzenbiers in German and were stored in cellars or caves for consumption until brewing could recommence. The actual term "lager" is derived from this practice and comes from the German lagern, which means, "to lay" or "to store". 

Duke Albrecht's prohibition on brewing during the summer was finally rescinded in 1850. By that time lager brewing had taken over in Germany and was beginning to spread to other parts of the globe, most notably Bohemia with the birth of Pilsner by Josef Groll in 1842. Of course, lagers are not the only type of traditional beers brewed in Germany. Weissbier and hefeweizen are brewed using top fermented yeast at warm temperatures and their history is quite interesting (although I will save that for a later time so this doesn't turn preposterously long).