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Airlocks
by Jeff Irvine

When I first found myself placed in front of a computer terminal that was hooked to "the net", the first thing I did was to look up what other people were doing in brewing beer.

After some fumbling around I stumbled on to RCB (I could tell you that that is short for rec.crafts.brewing, but if you found your way to this page, you probably already know that).

I lurked around awhile to see what people were doing, and mostly thought it was pretty weird. A lot of modern industrial techniques being taught to people, and not just like they were interesting or fun stuff to try, but as though they were NECESSARY for making good beer. This was pretty different from my experiences in making beer, and likewise what I've learned from chasing my greedy snout into traditional breweries to find out how they could make such wonderful stuff.

While I thumbed through this material and felt pretty much outside of what was going on, there was a hotly debated issue on "airlocks". It seems that some people, when they racked to the secondary, just put some plastic wrap over the tops of their carboys, locked it in place with a rubber band, and skipped all that stopper and water filled "bubbler" stuff.

Now this suggestion did not go unanswered...... There was tons of repliants who could quite easily explain that because of plain ol' "sandwich plastic's" permeability for oxygen, that this just wouldn't work.

Well the response from the plastic wrap user's side was not quite as adamant, and had not quite the rich fill of persuasive arguments for why it WOULD work, but it turns out if you really looked at the responses, it added up to several decades of brewing experience, where the brewers hadn't noticed any particular problems that turned up with their plastic and rubber band technique.

I guess it was a really lucky thing that they didn't know that they were performing the impossible, or they never would have succeeded with it.

As soon as I could walk on my foot again (the foot that was damaged by repeatedly kicking myself in the backside, for not having thought this up by myself), I thought this would be something worth checking on.

This was of particular interest since I HATE those little airlocks. I've bumped into three different kinds.... (1) beautiful old swan-necked things in glass, that I can break by sneezing within 3 blocks of them, and I can't seem to find anymore (2) Plastic things that look similar to the previous, but are so crappily made, that there are still "moulding marks" left on the stems, so they aren't really even air tight if you don't run them around on a belt sander first, and (3) some plastic round things that I actually quite like, and which I can also quite easily break, but I can never seem to find anymore (because everybody seems to stock (#2) "The Twisted Dildos", for some reason).

One thing all airlocks have in common... they are a royal pain up the backside to clean (I mean, a sanitation bucket just for that crap at racking time..... do I really have time or patience for that?)

This made the possibility of eliminating those particular little headaches extremely enticing.

I began quite humbly.... My nervous fingers stretching the unsanitised plastic over the top of a carboy, which was parked right next to a similarly filled carboy, capped with the "bothersome bubbler". I can tell you I felt great pangs of guilt, and held my breath through the entire procedure the first time I did this (I was, after all, putting my "child's" health at risk!).

Ya' know? I could never tell the difference between the two of them, fermented side by side, in the finished product. I've done the same many times since, and have never noticed a difference.

Thinking that either contamination (maybe) or oxidation (probably) were the most likely culprits that were being held at bay by the solemn ritual of the "foaming fountain", I thought it might be a nice idea to try a more extended "experiment".

Since I was planning to leave my lagering cellar unattended for 5 or 6 months, I thought this might be a good opportunity to put it to the test.

Racking from the primary, I filled two 25 litre demi-johns (big carboys) up with beer, the rest went into a 60 litre keg to which some wort was added. No CO2 flushing, or other attempts to maintain strict anaerobe conditions were done.

Of the two demi-johns, one was capped with an airlock, to which some 70% ethanol was added to the water, and the other got the plastic and rubber band treatment.

Now this is where the experiment gets a little cruddy... I would have liked to have had a good temperature control, but..... HEY! I WASN'T HOME! The temp was most likely between 0°C-8°C, the warmer temp towards the end of the half year they were unattended. This is both good and bad. Not having control over variables is never good, but on the other hand, a rising temp in the secondary is one of the best ways to invite "old barrel" flavours I know, and this is one of the things I wanted to look at.

Now the other crappy variable, is that airlocks should be refilled from time to time, because they tend to evaporate dry, but..... HEY! I WASN'T HOME! On return, I could just see the level had slipped below the slits in the airlock, so strictly speaking it wasn't doing it's job on the home stretch.

Despite these obvious deficiencies, let's see what we got.... I racked off a portion from both, and artificially carbonated in individual kegs. They both were "oxidised tasting" to me, and there was a SLIGHT difference between them, but I couldn't say that one was in better shape than the other. In fact, surprisingly, the primed and kegged version was NOTICEABLY more oxidised than the other two.

I thought it would be nice to pull in a bit of objectivity on this, so I hauled these kegs to a local gathering of brewers and let them blind taste them. I tried to use the criteria that I have previously applied.

Well, I think I was just a wee bit late into those particular festivities to gather any practical information from this Bergslagen crew. I thought I would keep things simple by letting people simply check "better", "worse", or "the same", beside each of the two beers on a judging sheet. When people start marking that one beer was "better", and the other was "the same", you really have to wonder how discerning the opinions I was gathering actually were.

What resulted from that ill-conceived haphazard evaluation, was that most people thought it was a pretty respectable drop (note; not my opinion), but there was certainly no concourse of opinion in favour of one or the other.

What I think is probably significant here, is that in this "worse case" of tempting your beer to spoil by oxidation, there seems to be no obvious advantage of the traditional "tooting tower" over the plastic wrap and rubber band method.......Hmmmm. Seems I've once again wasted a lot of time following unfounded truths.

Just as an afterthought, I thought I'd try the ol' Krauzen on the remainder of the beer. These were racked off to separate kegs with a 10% Krauzen. My experience has always been that the voracious appetite of primary fermenting yeast for oxygen, and it's incredible reductive power, provides a veritable fountain of youth when kegging (I have easily stored kegs of similar lengths of time with impunity with that technique).

I wondered if the omnipotence of the Krauzen could even provide a reductive power so mighty that it could reduce the previous oxidative effects to a former state.

What I achieved after a few weeks, was something that had the aroma of yeast stress (<- read "farty") with the pungency of a distinct lactic acid taste, laid over a well lagered pilsner.

I suppose I could have poured a Dr. Pepper in it and passed it off as a "Kriek", but I don't think I would have been any more pleased with it.

Fortunately my neighbour "Dave" called. He is less of a beer "connoisseur" and more of a beer "kind-of-sewer".

After 15 choruses of "The Tennessee Waltz", that particular disposal problem was solved.


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