Week 4 at UC-Davis
If I were to ask you to choose the one ingredient used to make beer that is the least expensive in a commercial setting, which would it be? Water? If breweries were more efficient perhaps, but the reality is that a lot of water is required for heating, cleaning, and the beer itself. The yeast? Well, the yeast takes a fair amount of maintenance with temperature control, lab work, proper disposal, not to mention the man hours involved with some of those processes. The malt? Hopefully you didn’t go there. Being a homebrewer, you know that's the largest part of our total bill at the local homebrew shop for any given batch. So unless your brewery is solely making Quadruple IPA’s year round, the answer is hops. I found this a bit surprising considering it’s substantial contribution to the end product.
This week’s lectures were mostly dedicated to the Humulus lupulus plant and the various roles it plays in the brewing process. Most of you already know that the alpha acids in hops provide bitterness to the wort after conversion to iso-alpha acids in the boil. You also know that the hop oils contain various compounds that give us a variety of flavors and aromas depending on which particular hop variety is used. In addition, you know that hops also have a preservative quality that increases your beers shelf life. Hopefully I’m not alone here, but until now, I’ve never fully understood why. How did those bitter beers that were loaded on to a ship in England make it all the way to India without spoiling? Well my friends, those very same iso-alpha acids many of us love play a significant role when it comes to beer preservation. When they come in contact with beer spoiling bacteria, the iso-alpha acids disrupt the proton gradient within the cell and inhibit their ability to transfer nutrients across the cell membrane. They essentially cause the bacteria to starve to death. Bad for them, good for us brewers. Beers naturally low pH and ethanol content are also contributing factors to a it's longevity.
We also learned about a variety of hop products that are used commercially in brewing. There are pre-isomerized alpha acid extracts that can add bitterness after the boil. One in particular is used by a large American brewery and has been chemically altered in a way to prevent the beer from being “lightstruck” or skunky despite it being packaged in a clear bottle. I can think of a few others that come in green bottles that should start using that very same product. There are also hop oil extracts that you can dump into the beer just before packaging to give additional aroma. One of the drawbacks to using these products is that if you already have a recipe that uses whole cone or pelletized hops, it is very difficult to replicate the taste/aroma of the original beer without anyone noticing. It is rumored that some companies have done so gradually over time to prevent any consumer blowback. Very sneaky.
In a completely unrelated topic, Dr. Bamforth went into great detail about the tragic downfall of cask conditioned ales in Great Britain and Margaret Thatchers role in the whole fiasco. She championed legislation which led to the demise of the brewery owned pubs, which according to Dr. Bamforth, resulted in 3rd party pub owners mishandling casked beer to the point that their quality sank to new lows along with the number of breweries that produced them. He also said that if you are lucky enough to find a well made and properly handled English cask ale that you'd be a fool not to try it. In his humble opinion, it tastes like “an angel weeping on your tongue”. I'm not really sure what angel tears taste like, but it sounds like a good reason to visit the U.K. to me.