Bubble bubble?

In my opinion, one of the best stages in the brewing process is the first few days after a beer is brewed, when the yeast is really kicking into high gear.  As you may have noticed in the video I posted, with the crazy action in the carboy, it can get pretty spectacular.  Since that particular brew was poured onto a “yeast cake” (the stuff at the bottom of a previous batch) the yeast was plentiful and ready for action.

I brewed another beer on Sunday night.  this one is from a recipe I’ve used before.  It’s Charlie Papazian’s “Goat Scrotum Ale” recipe, which is sort of his attempt at an historic porter.  Along with malt extract (which wouldn’t be historic at all, since malt extract is sort of condensed malt, something brewers wouldn’t have used hundreds of years ago), you pour in brown sugar, molasses, corn sugar and then can choose from a list of other ingredients.  In my first attempt at this beer, which was I think my third or fourth beer, ever, I added cocoa and then at the end of the boil, I poured in a large can (3Lb) of cherry puree.

Now, I’m going to step back a bit because some of the jargon and processes may be alien to you.  So I’ll explain a few things

1) To make it extremely basic, when you brew, you boil a bunch of stuff in a pot, making a nice, sweet liquid (called wort) in which brewing yeast will have fun eating the sugars that it can, and pooping out alcohol while farting out carbon dioxide.

2)  The process of boiling is usually called “the boil.”  At the end of the boil you cool the wort, pour it into a “fermenter” and add yeast.

3) Many fermenters are glass carboys, basically they look like glass versions of those blue five gallon bottles that you put in the office water cooler (or a home one).  In fact, I believe many carboys used to be exactly that, except made out of glass.  (You’ve seen pictures of my carboys, and another one is below).

There is a lot more to brewing, but those are the basics.  If you were to watch me on brew day, you’d see me soaking some grain, then boiling the water I soaked the grain in, then add a beige powder (the Dry Malt Extract), and then little green pellets (hop pellets).  The boil usually lasts 60 minutes, during which time I likely will add more hops, at various times (the later in the boil you add hops, the more flavour and aroma you get out of them, the earlier, the more bitterness you get out of them–each type of hops has its own level of bitterness and characteristic flavours).  I would also add stuff like Irish Moss (a clarifying agent) and maybe other things that I feel are necessary.  Then I’d cool it, filter it into the carboy (to get the hops out, and other proteins that have congealed during the boil) add water if I need to “top it up” to reach my desired volume, and then add the yeast.  I’d take a sample to test the original gravity of the beer (this will allow me to calculate alcohol content and determine when the yeast has finished doing its job).

Speaking of sugar I might add other things, non-malt sugars like molasses, corn sugar or brown sugar are known as “adjuncts” because they are sort of supporter sugars that yeast will also eat.  Other sugars, like lactose, are not digestible by yeast.  So if you add lactose (and there are beers with lactose, for example “Milk Stouts”) you are going to get sweeter beer with more “body” because there’s more sugar remaining.  To get a very “dry” beer ( not a lot of sugar) you’d add sugars that yeast can eat.  There’s more, but that’s enough.

Okay, that was a major digression.  Back to my porter.

When I made that porter the first time, remember that I added the cherry puree (not extract, but just pure, pureed cherries) at the end of the boil.  It all went into the carboy, and I added yeast.  Usually it’s good to make sure the stuff you’re adding gets boiled a bit because it will kill bacteria, and bacteria is bad because you’ve just made a pot of stuff bacteria loves to eat.  You want the yeast to eat the sugars, and beat the bacteria to it, so sanitation is fundamental to brewing.

Oh, that was another digression.

Anyway, because the cherries went in the pot right after the brew, but before fermentation started, something unfortunate happened. Yeast, you see, also love cherries. They are adjuncts, of sorts.  Fructose is highly fermentable (hence wine, cider, etc).  So when I added the cherries, I gave the yeast time to really lay into the fructose, while it was having the orgy of eating, pooping, farting and reproducing that it normally has with wort.  Oh, did I mention that the process of fermentation is basically when yeast “eat sweet things and have reproduce”.  As a brewmaster friend of mine once said: just like humans, yeast like to eat sweet things and reproduce.

So, since the yeast could jump headfirst into the cherries, they pretty much devoured the fruit flavour, aroma and colour.  There was very little evidence that I added cherries.  Well, very little discernible cherry-ness.  My sister, who is not a big beer drinker, really enjoyed this beer.  She suggested it may have been because it had wine properties, which might be so, since the fermented cherries would have done that.

So this time I’m trying something different.  Except for a few tweaks, the recipe is the same.  But I’m going to wait on adding the fruit.  In about five days I’ll pour a can of raspberry puree (yep, going for a chocolate raspberry porter this time) rather than doing it right off the bat. If I really wanted to ensure a full up front fruitiness, I’d “rack” the beer into “secondary” (ie: siphon it into a second fermenter) and add the fruit then.  By doing this, I will get the beer off the yeast cake, so less yeast will lay into the fruit (after you rack it, there is still yeast floating around, but most of it is sitting on the bottom of the carboy.  This you either dump out or use for another brew–as I did with both of these beers I brewed this weekend).   However, I don’t want the raspberry to overwhelm the other flavours in this beer, so I’ll try the late in the fermentation cycle approach this time.  If it doesn’t work, there’s always next time.

Now remember how I remarked on the action in the carboy of my other beer, the IPA?  The foam on the top is called “Krausen” (pronounced KROY-sen).   That is caused by a variety of factors, from what I understand related to the proteins or other compounds in the beer.  For this porter, there was a vigorous fermentation (ie” lots of Carbon dioxide produced) but the krausen on this one is significantly subdued.  This is likely due to the effect of cocoa butter or fat from the cocoa powder.

Here is a picture.  Sorry, it’s sitting in a plastic bucket (to keep it off the concrete floor) so it’s not as easy to see.

Porter in front, with the IPA behind. Notice how low the krausen is?

It’s hard to see, but the little krausen that’s there is very creamy and pillow like.  Chocolatey.  Can you see the contrast with the IPA?  It’s more like tight soap bubbles, but very uneven and disjointed.

This is going to be a good autumn.  Especially because my next beer is a pumpkin porter…


About danmalleck

Medical historian and jack-of-all-trades curmudgeon. I tend to ramble about politics, social incivility, and our self-centred culture more interested in buying the next cool ringtone or LED TV than actively engaging in the sorts of discussions and issues that matter. The more opportunity we have to buy more stuff, the less concern there is, it seems, in politics, social justice and let's face it, basic human decency, unless those things actually can save us money or get us more things to show how awesome we are through displaying our material wealth. And I like to brew beer, make cheese, and put food in jars.
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