Sunday, December 30, 2012

Ales and Lagers - An Introduction to Beer


I think you'd benefit from a quick run down of the ingredients of beer and what each does and how it affects the taste and character of beer. First is water, obviously, which should be clean and more or less balanced in terms of pH; water can be the simplest thing or very involved when we get into mash temps., residual pH, relative mineral concentrations and other chemical considerations and so on. For now lets leave it as being simple and not pay it any more attention.
The next ingredient, really at the other end of the dial, is the yeast. This is a galaxy on its own and really, like the intricacies of water chemistry, best left alone for now. Just keep in mind that much of the flavor of beer comes from the yeast, which ferment the sugars into alcohol and CO2 and there are two major classes of beer depending on the yeast, lagers and ales.
The other two ingredients, barley and hops, are where we should really concentrate for someone like you. What are they and what do they do? Barley is a grain, like wheat or rice or corn or oats, and it's the traditional grain for making beer although others can be used like those just mentioned. Barley grains are subjected to a few processes to get them to a stage where they can turn all the starch or endosperm into sugar for the yeast to eventually eat and ferment into alcohol. There are two major types of barley, 2-row and 6-row, quite similar to one another, each of which can be subjected to additional processes to develop flavor characteristics. This is where I think you might benefit from learning something about the process as it relates to your ability to select a beer you will be likely to enjoy.
First, after barley is malted, that is germinated and then kilned just enough to halt further germination and sprouting, it can be roasted to varying degrees. Think of a piece of bread; if you eat it straight out of the oven a bit undercooked it will be a bit bland and will taste more like the wheat itself than if you take a slice and then toast it a while. Once it's toasted it will have that wheat taste but it will also have other tastes, those we associate with toasting, nuttiness, caramel, a little burned and so on. What if we really toasted the bread to where it was nearly blackened? That would be quite a different taste, bitter and less like wheat. We can do the same with barley for beer; roast it, like coffee beans, to varying degrees to bring out those different flavors. The more we do this the darker the grain and the darker the resulting beer. We can also mix grains of varying degrees of roast together for one beer, a bit of light and bit or dark and so on, to further complicate things.
Once we have our grain, whether not roasted at all and just plain, or roasted to the point of being black, we then have to basically soak the grain in water for some period of time, this is before we actually brew the beer, at some temperature to get the enzymes within each kernel to convert the starches into small sugars the yeast can metabolize. The different temperatures at which we do this give us different sugar and carbohydrate profiles; the overall temp. window is about 145F to 165F in terms of extremes, the best ranges are about 148F-152F for one type of conversion and about 156F-160F for another type of conversion. The first type breaks down the starch molecules in such a way so as to give us a very dry beer, in other words it gives us a lot of simple sugars which the yeast can totally convert into ethanol leaving little else behind, while the other type breaks down enough to still give us alcohol but leaves a lot of longer chain sugars which the yeast can't eat but our tongue can still detect slightly as a sugar. This means that if we do this, mash the barley, at a lower temperature we get a dryer beer and the higher we do it the more sweet and malty a beer we get.
Now, it's important to note that we don't usually do one or the other, we can try to reach a compromise so we get something in between, we might for instance mash somewhere in the middle, say 154F, or we might start low for a while then raise the temperature half way through. Basically, the point I'm trying to make, is that there are two major barley characteristics, dry and alcoholic and often a bit thin, or sweet, thicker and full of body. Light beers are often dry and dark beers a bit sweet.
A quick note here returning to yeast; there are two major types of beer which I mentioned before and with which I am sure you're already familiar, lagers and ales. These are basically the same type of yeast but different strains, although there are some different species altogether in some cases, and these different strains ferment best at different temperatures. The Bud and Coors and Miller and Michelob you reference are examples of lagers; there's a whole story behind why American macrobeers were and are lagers and where that came from and why ales were the default face of microbrews thereafter, but that's a different story which could take up a lot more room than I'm already doing here, but, basically, these beers are lagers and lagers are beers that ferment at low temperatures and give light, clean flavors. Ales are more versatile and ferment higher and can be light but can also be dark, like the Guinness you like. The point here is that there are two major branches of beer depending on the yeast, lager and ale, and a good ale is a dime a dozen, they're easier to make, and a good lager is a bit more difficult, plenty of cheap bad ones out there. An example of a quality lager is the Sam Adams you mentioned.
Now, on to bitterness, the last ingredient, hops. Hops are the oil and resin laden glandular buds of Humulus lupulus, a plant not too distantly related to the Cannabis genus and similarly containing many pungent alkaloids. These compounds give beer its bitter taste and if treated properly its spicyand often citrus nose and bouquet. These compounds are called collectively alpha acids and part of the reason beer needs to be brewed, boiled, is to cause a reaction with these acids wherein they change shape slightly and they thereafter gain shelf life and bitter the beer. Depending on when hops are added to the boil, this well after the barley has been mashed and sugars converted, they give varying degrees of bitterness. Just as when cooking where you can add your herbs at the beginning and by the end they're all cooked down and not vibrant or add them at the end right before you're done so they stay green and pungent so too do hops retain their flavor the less they're cooked. So there are two factors where, boiling longer and getting them to bitter the beer or adding them later so they keep the higher notes and aromas, and so we add hops in stages, a bit early on and then a bit later to get the full range of their flavors and aromas.

1 comment:

  1. Awesome description! I am a beer fanatic and this was very informative. Thank you

    ReplyDelete