Wednesday, June 20, 2012

The Mr Beer Years

The starter kit came with the ingredients for the West Coast Pale Ale, which is kind of a classic American middle-of-the-road beer. Light in color and body, not too much hop bitterness. The recipe uses one can of a hopped malt extract. Basically, the jobs of extracting the sugars from the malt, and boiling the hops to add bitterness have already been done. Dilute the hopped malt extract to the full volume and you have the wort (the name for unfermented beer). To add a little more body and alcohol, the recipe includes Booster which is basically simple corn sugar. Once all this is mixed together, the yeast is added and fermentation takes place over a period of one or two weeks. I just let mine go two weeks to make sure fermentation went to completion despite the cold temperatures in my house. I put the fermenter in the cloakroom, which tends to be the warmest area of the house in winter.

When the beer is put into bottles, a little extra sugar is added and the beer is left to carbonate. The sugar is fermented as usual and the carbon dioxide produced cannot escape thru the sealed cap so the beer becomes carbonated. This takes another one or two weeks at room temperature, then the beer can be chilled, and drunk.

The West Coast Pale Ale was a success in as much as the beer was drinkable! My next beer was the American Devil IPA which used two cans of hopped malt extract, and skipped the Booster resulting in a slightly stronger brew. That turned out well, but not as hoppy as the name would suggest. I brewed a Vienna Lager which was very popular but wasn't a true lager as it used the same Mr Beer ale yeast as the other brews. I tried an Oatmeal Stout which was good during the cold weather, and a Doppelbock/Brown Ale that came out like a porter and was one of my favorites. From that point I tried to introduce a different element to my brewing with each beer.

I brewed a recipe called KT's Caramel Apple Cider that was half beer, half cider and used a champagne yeast to give the beverage a dry finish. It took a looong time to ferment and condition but ultimately came out really well. I brewed the First Pitch Pilsner which was my first time boiling some hops in the wort to add more hop flavor, and used an actual lager yeast (although I probably didn't ferment at a low enough temperature). The result was again very pleasant but not quite the right style.

My sister-in-law had given us some preserved strawberries so I made a slightly amateurish attempt at a lambic. I had read that lambics are traditionally a brown ale base, but wanted the beer to have some sourness so combined the brown with a red ale, then threw in a couple jars of strawberries. Getting the beer in the bottles without clogging the spigot was a challenge, but I was very pleased with how it turned out. A little sourness and not too much fruitiness, but you could taste the strawberries.

Next I brewed a beer starting only with the unhopped malt extract. I boiled the wort for a full hour with progressive hop additions to create a truer pale ale. I was also able to start with more that the final volume of liquid in the kettle. Some would evaporate during the boil, resulting on the correct volume. My maximizing the volume of liquid, the utilization of bittering compounds in the hops is also maximized, allowing me to really amp up the bitterness. I was really pleased with how that beer came out, although I think I ended up giving a lot away!

I returned to the Vienna Lager but this time used a real lager yeast and kept it at the right temperature (around 50F) but I;m not sure I can honestly say that it came out much better than the first attempt. I also tried to brew a wheat beer (hefewiezen) which came out more like a light ale. I could tell that I was starting to reach the limits of what could be achieved with the Mr Beer setup so began to transition to 5 gallon brews using some slightly more advanced techniques. However, I think the eleven beers I brewed with Mr Beer gave me a solid foundation for my future brewing endeavors.

Sunday, June 17, 2012

How I Started Brewing

Getting into brewing is a daunting prospect.  I had been thinking about brewing for a while and kept mentioning it to my wife, but there were three barriers that held me back.  First is the cost.  I am stingy, and so while the beginners equipment if not very expensive, I had a problem with the fact that a primary fermenter costs about $16, but its just a paint bucket with a few minor alterations.  Surely I would just buy a $5 paint bucket and put a rubber grommet in the lid...but of course I never got around to it.  Second is the possibility of failure.  It takes several weeks to get to a drinkable product, and the process seems full of potential pitfalls.  Was I capable of putting it all together?  And finally was the issue of temperature control.  Like I said, I'm stingy, so my house is cold in the winter and hot in the summer.  Would I only be able to brew in the spring or fall?

Eventually my wife got tired of hearing me talk about it and bought me a Mr Beer kit for my birthday.  Mr Beer have created an entry level brewing system that I'm sure lots of brewers look on with scorn, but I'm going to stand up for them because I think their system is actually quite clever.

The whole concept is based on hitting the correct pitching temperature every time.  Making beer inevitable involves hot water, but at the point the yeast is added the temperature cannot be more than about 80F, preferably lower, or the yeast will instantly die.  What Mr Beer have you do is heat up a set amount of water to boiling, add hopped malt extract, then make up the mixture to the 2 gallon mark with room temperature water.   The resultant volume is always going to be about the right temperature for pitching ale yeast.

The Mr Beer system also compresses the amount of time required to brew, which I think makes it easy to set aside a slot of time and really concentrate on your technique.  One of the most important aspects of brewing is good sanitation, as any contamination from bacteria can ruin a batch.  Good sanitation needs to continue right thru until the beer is drunk, but on brew day it is especially important because you are in the business of preparing a nutrient rich liquid for your yeast to digest.  If anything else gets in at the start it has a chance to compete with the yeast.  After fermentation is in full swing there is less chance of a contaminant being able to gain a foothold.

The Mr Beer kits come with a no-rinse sanitiser which works well because it doesn't create a lot of foam, which can be intimidating for a novice.  While there are many limitations to the Mr Beer setup, they definitely come through on the promise of allowing a complete new-comer to brew a decent beer on the first attempt.

Sunday, June 10, 2012

Water

What can really be said about water?  It's just the vehicle for all the other wonderful components of beer, right?

In fact, water has again a rich story in the history of brewing.  Certain styles of beer developed in the regions that they did because they were a good match for the characteristics of the local water.  Famously, the pure water of Pilsen used for brewing crisp, clear pilsners, and the chalky water of Burton, where many classic British ales are brewed.

For the homebrewer, the biggest challenge is removing chlorine from municipal water supplies.  Chlorine can combine with organic compounds from the malt and produce medicinal off-flavors.  But some brewers take things a step further in adding specific minerals to their water to replicate water profiles from around the world.  In any case, some minerals and ions are vital to ensuring healthy yeast growth.

These post barely scape the surface of what there is to be know about even these four simple components of brewing.  I plan to revisit these posts and update them as I have the time.  For now I hope they will be useful in allowing non-brewers to follow along with my descriptions of my brewing adventures.

Hops

Sugar from malt has already been converted to alcohol by yeast.  So why do we need hops?  The hops play two key roles.  Firstly, the residual sweetness of any unfermented sugar is pleasantly balanced by the bitterness provided by hops.  Secondly, the hops have anti-microbial properties that help prevent the beer from spoiling.  Several other plants have been used to the same effect, for example different types of roots in root beer, but for various historical and geographical reasons, hops won out.  Modern-day Germany is the epicenter for hop production as the climate there is suited to their cultivation.  It is not co-incidence that the Germans are then famous for their beer, while their Southern neighbors made wine from the grape vines thriving in the mediterranean regions (and those further north made vodka from whatever they could get to ferment).

The bitter compounds in hops are a class of chemicals called the alpha acids.  These acids are present in the hop cones, which are the female flower clusters of the hop plant.  Interestingly the alpha acids have to go through an isomerization process to become bitter.  Isomers are two different arrangements of the sample atoms.  The isomerization occurs during boiling, so a key process in brewing is the boiling of the hops in water also containing the sugars extracted from the malt.  Isomerization is mostly complete after 1 hour of boiling, so hops boiled for one hour contribute maximum bitterness.  Later hop additions provide other aromatic compounds that contribute to flavor and aroma.

Malt

I want to start with malt because the malt provides the raw materials for all the wonderful biochemical processes that occur during brewing and that result in alcohol, of course, but also all the other flavors that form the body of the beer.  But to get to malt we first have to go back to grain.

Grain seed contains the genetic information to grow another plant.  But to have any hope of achieving that aim, it also has to have a large store of energy to get the whole process started.  Until the first leaves emerge, and the plant can start capturing the energy from the sun, it has to completely rely on what it brought with it.  The energy is packaged as starch.  Starch is comprised of long, branched chains of sugar molecules, so it is a space-efficient way to stow the cargo, but the chains have to be broken before that energy can be accessed.  To bust open the chains, the grain also has a supply of enzymes, that can snip apart the starch into its constituent sugars molecules.  When the grain is malted, those enzymes are harnessed to do that exact job: convert the starch into sugars than can be fermented by the yeast into alcohol.

Malting, therefore, is basically playing a trick on the grain.  By warming it up in a moist environment, the grain is fooled into starting the germination process.  The enzymes are activated in those favorable conditions, and they begin to transform the store of starch into useable sugars.  Then, before the grain can get as far as sprouting, the process is abruptly halted by drying, and we are left with malt.

As you will discover with all aspects of brewing, the theory is relatively simple, then you walk in to a homebrew store and see a wall of shelves filled with a massive variety of malts and you realize the many layers of complexity built on top of the basic concept.  So lets think about some of the factors that can alter the properties of the malt.

First of all, consider the type of starting grain.  Barley is the most popular malting grain for making beer and whiskey (the two drinks are closely related).  The reason is that the starches in barley are readily converted to sugar.  In other words, they are relatively easy to malt.  But other grains are used, either on their own on in conjunction with barley to add different characteristics to the beer.  Common examples are wheat, corn, rice and oats.

A second way the malt can be altered is by roasting it.  This is a delicate process since we do not want to completely denature the enzymes that we will later rely on to perform additional conversions.  But different roasting temperatures and times can provide different colors and tastes.  As the malt darkens, nutty, chocolatey, earthy or even smoky flavors begin to be produced.

So now we know that malt is modified grain that provides the sugar for fermentation and contributes to the flavor and color of the beer.

Yeast

It would make sense to talk about yeast next.  The yeast is going to convert the sugar from the malt into alcohol by fermentation.  Fermentation is an anaerobic process, which means it occurs in the absence of oxygen.  Yeasts are single cell organisms from the kingdom Fungi.  There are two main species of yeasts  used in brewing.  Ale yeasts are usually strains of the species Saccharomyces cerevisiae, while lager yeasts are Saccharomyces pastorianus.

Ale yeasts are 'top-fermenting' yeasts, and prefer warmer temperatures, while lager yeasts are 'bottom-fermenting' yeasts and prefer cooler temperatures.  There are many different strains of yeast, each of which is typically used to brew a particular style of beer.  The strain of yeast used contributes a lot to the overall flavor of the final product.  There are several large commercial yeast labs that produce their version of all the major strains of yeast and label them with the style of beer they are traditionally used for.

How does the yeast contribute so much to the flavor profile?  Well, the yeast is a living organism, so as well as doing the heavy lifting of converting sugar to alcohol there are a variety of other reactions occurring that add to the flavor and mouth feel of the beverage.  There are also other, simpler reasons.  For example we need to consider the attenuation of the yeast.  That is a measure of how completely the yeast uses up the available sugar.  No yeast converts 100% of the available sugar and the remaining sweetness is a big part of the style of the beer (in the same way that wines are classified by being sweet or dry).

One big class of chemical compounds produced by yeasts is the esters.  Esters are notorious as flavoring chemicals, as they have characteristically fruity odors.  Most chemistry students will at some point be introduces to isoamyl acetate, the chemical used to flavor pear drops.  In the brewing world, perhaps the most famous esters are those that give banana flavors to many belgian styles, but there are many beers that benefit from different fruity notes.  The same belgian style yeasts that produce banana flavors also tend to produce phenols, which can be perceived as a clove-like flavor.  Another common by-product is diacetyl, which tastes like butterscotch.  Generally this is considered a bad flavor in beer, but can be a part of certain styles.

Understanding all these side reactions is a big part to understanding the brewing process.  At first it is easy to wonder why the beer isn't finished after a week.  The fermentation is usually complete by then, but it can take several more weeks under particular conditions for some of the other characteristics of the beer to develop.

Saturday, June 02, 2012

Crabtree Falls

Crabtree Falls is billed as the tallest waterfall in Virginia, but not in the sense of a single sheer drop.  Instead it cascades in a series of sections.  Still, I was looking for a relatively short hike and this was nearby, and it turned out to be worth visiting.  The falls are within the George Washington National Forest and so the trails has been heavily modified with steps, stairs and hand rails.  The path travels 1.7 miles alongside the falls with several decks built for viewing the more spectacular parts.  Despite the steep climb the walking was never too strenuous and it was nice to take a break regularly and enjoy to cool breeze coming off the falling water.  When you get to the top, the view of the valley is pleasant but the falls themselves are hidden over the ledge.

On the way back down I couldn't help wondering, where does all the water come from?  When you're at the top of the falls you can't be very far from the top of the ridge.  So there isn't much land area to catch rainwater to feed the falls and there also wouldn't seem to be anywhere for a large store of water to build up so that the flow would remain steady for a while after a rain.  There certainly seemed to be a lot of water coming down.  But then it occurred to me that the flow rate must be the same from top to bottom, and at certain points there was just a small stream of water running between a few rocks.  At first it didn't seem possible that the small stream could be carrying the same volume of water in the same time as these large cascades of white foamy water.  But the answer is in the foam.  When the water splashes over the rocks and gets foamed up with air it makes it look like a much larger volume than it really is.  There's also the fact that the width of falls at any point is inversely proportional to the depth of the water there.  When the depth of the water is very shallow (such as when it runs down a steep rock face) it can be spread out over a surprisingly large width.  Finally, I think the water stretches out more when it flows faster, like cars on a highway.  Even though the distance between cars (or water molecules) is large, the overall rate of flow is still high because the cars a moving very quickly.

The upshot of all this is that there probably wasn't as much water flowing down the falls as it initially appeared.  I thought about trying to estimate some depths, widths and speeds.  There was one spot where 'V's of light foam pulsed down the water as it flowed across a large flat rock.  I figured the speed that the 'V's were travelling was probably about equal to the speed of the water.  Speed x cross-sectional area would have given me a rate, and I could have thought about what volume of water would need to be stored at the top of the falls to maintain that kind of flow.  When I got to the parking area again I did look at the map and saw two streams feeding the falls, so maybe the land plateaus a bit and there is more catchment area than I think.

Anyway, I ultimately decided to let go of the maths and just enjoy the beauty of Crabtree Falls