HBK #4, Day One, Part Three: Hops, Sterility, and a Tiny Bit About Yeast

When last we left our Char-Cole Porter, it was sitting in a boiling kettle, 147 °F, and giving off a delicious aroma into the brewing space (i.e. Tim's kitchen).  But that, obviously, is not the end-game of our beerly pursuits:  the beer was still in its wort form, essentially just a flavorful sugar water.  If we were to pour it into bottles and let it sit in Tim's basement for a few months, we would still just have sugar water (note:  not beer) when we opened it in the Spring...except most of the sugar would probably have been converted to toxic and generally unpleasant things by the copious bacteria to which it had been exposed. This is why our next step is to take the wort in the boiling kettle and - wait for it - boil it.

Tim's awesome propane burner can boil this amount of liquid (probably between seven and ten gallons) inside of ten minutes, but it's very important that the wort be monitored carefully.  That's right:  in blatant defiance of the "watched pot" proverb, Tim stood and waited for the wort to boil.  If a wort is allowed to boil out of control, the result is more detrimental than if the water from a pasta pot were to overflow.  The bubbles that form when a wort boils are formed from the surface tension of the water enclosing pockets of air, and these bubbles are especially hearty because they have a high sugar content.  Consequently, if the bubbles exit the kettle, the wort loses sugar disproportionately...and lost sugar means lost potential for alcohol content in the finished beer.  (And while high alcohol content isn't the sole reason we make beer, it certainly doesn't hurt, right?)

So, skipping ahead, the wort has reached a boil (it's not lost on me that both warts and boils are gross skin conditions...but try to pretend this sentence doesn't sound so revolting), and the burner has been adjusted so the boil is under control.  We want the wort to boil for an hour, both to establish sterility and to infuse flavor, which is where the hops come in. 

(A brief side note:  I apologize for the lack of images available from this point on.  See, the fun part about making beer - a generally time-consuming and tedious process - is that you get to enjoy beers that have been previously made while doing so.  Around the time of the boil, I had established a buzz well past sufficient to cause me to forget my duties as a photographer.  I'll try to get some pictures of the post-boil process for future entries.  For now, though, I hope that you have a good imagination, and that you can appreciate that I was having a far better time drinking than I was shooting photos.)

Now that we've gotten the disclaimer out of the way...  Hops are wonderful.  If you enjoy a good, bitter, IPA, then you probably agree with me.  If you've ever handled hops in their pre-beer form, then you definitely know what I mean.  Hops are technically flowers, though they look more like green pine cones while still attached to the plant.  They are then dried, packaged, and sold almost exclusively as a beer ingredient, as they haven't found many other uses in the world.  In their dried state, they're light, fluffy, and uniquely aromatic.  You know the flowery scent of a strong IPA?  Imagine that, but more concentrated, and without any undertones of "beer smell." 

Hops are added at several points during the hour-long wort boiling process.  Hops added earlier are used to infuse flavor and bitterness to the beer, and hops added later are the ones that give that hop aroma I just mentioned.  Chemically (alert!  whenever you see the word "chemically," feel free to skip ahead a few sentences to avoid falling asleep), the reason for this is that hops contain both alpha acids and beta acids, which react differently in the heat of the boiling wort:  alpha acids isomerize (memories of high school chemistry class, anyone?), or convert by rearranging their molecular structure, into bitter-tasting molecules; beta acids do not isomerize, and therefore do not contribute to the flavor but instead accentuate the floral scent of the hops' natural oils.  To maximize isomerization, the "bittering" hops (higher in alpha acids) are added early in the boil; to affect non-bitter hop flavor and aroma, "aromatic" hops (lower in alpha acids, higher in beta) are added in the last half of the boil.

So, an hour goes by and various amounts of various hops are added (sorry, I don't have my notes...but do you really need to know the names, times, and alpha-acid contents of the different hops?  What, are you trying to steal our beer?  ARE YOU?!), and the boiling hot, hops-infused wort is taken off of the burner.  By this point, it has boiled down to roughly the exact amount of liquid we had hoped to end up with...I assume this was just due to Tim and Chris's experience with brewing...and it's filled with nasty, soggy chunks of hops.  Oh, and it's still boiling hot.  Not a good temperature for brewing.  Thankfully, Tim is in possession of a badass copper coil which attaches to a garden hose (did I mention the boil took place on the front porch?  Quaint, right?) and runs cold water through the wort without diluting it at all (I know, a picture would really be nice here, wouldn't it?).  The coil is placed in the pot about ten minutes prior to the end of the boil so as to keep the process as sterile as possible.  Then, when the boil ends, water is run through the wort until it's roughly down to room temperature, and the kettle is brought inside.

Now, before we go any farther, let's talk about MICROBIOLOGY!  (Again, I'll try to do it in three sentences or less; skip ahead if your eyelids just got heavier.)  Bacteria are everywhere all the time, and while air is considered to be more or less sterile (though this is technically not entirely true, it's just something that we assume to be "true enough for our purposes"), NOTHING ELSE IS FREE OF MICROSCOPIC LIFE, and so we must sterilize everything.  If we pour beer through a non-sterile funnel, it will rot; if we store beer in a non-sterile fermenter, it will rot; if we so much as fail to sterilize the caps for our bottles, the stupid beer will rot.  In short, since it's going to be stored at roughly room temperature, we need to kill any bacteria before they even have the chance to thrive in this delicously sugary environment we've just created for them.

As a result of these prokaryotic terrorists' incessant attempts to ruin our brewing party, we have spent part of the boiling time prepping in our battle against them:  our funnels, our carboy (the six-gallon jug we'll use as a fermenter), and even our hands have been soaked in an iodine-based (no bleach here, Tim is all-green) disinfectant.  Once everything is sterile, the kettle is emptied (through a sterile collander to catch the soggy hops, and through a collander-sized funnel to catch the, you know, beer) into a carboy, where it will sit for the next several weeks, bacteria-free and fermenting away.

But wait, how is it supposed to ferment if it's still just glorified sugar water?  That's where the yeast comes in...and, really, that's about all I'll say about yeast, since I plan on writing about it in great detail in the near future (with pictures!).  Basically, the yeast is added, an airlock fermenting cap is put on the carboy, and the beer is put away to ferment.  The long process (and the long-winded, sparsely illustrated blog entry) has finally come to a close...for now, anyway.