Science History – The Big Room (and the little things in it)

“Improvements in the Fermentation and Maturation of Beers”

Judging by my webserver’s logs, almost nobody actually bothers to click through the blog-carnival host’s site to read my Giant’s Shoulders” posts. This could be due to a secret conspiracy involving famous bloggers and several shadowy government agencies. I suppose, though, that there’s a chance that simply nobody but me is that interested in non-medical microbiology. Well…today’s post is an attempt to disprove that concept, for what aspect of non-medical microbiology could be more universally appealing than beer?

Unfortunately, in the middle of trying to assemble this posting, I see the February host has decided to put the carnival up a day early, undercutting my experiment. See, I told you it was a conspiracy! I suspect the Secret Cabal of Popular Bloggers was getting pressure from the Trilateral Comission, the NSA, and Pepsico® to silence me, so they had to do it. At least being forced to miss one, I am now free from the “I’ve been posting to these since the beginning, I can’t miss one now!” treadmill.

That means, loyal readers, that you get to see this post a month before everyone else! Hooray! Stick it to The Man™! Comically paranoid rantings aside, it also means I can split this up into more than one post, which may be more readable considering how much ground the article in question actually covers. Today’s Classic Scientific Paper is:

Nathan, L:”Improvements in the fermentation and maturation of beers.”; 1930; J. Inst. Brewing; 36; pp538-550

I ran across this reference recently while working my way through an industrial microbiology text[1] that I checked out of the campus library. According to the author of this text, “The use of cylindro-conical vessels in the brewing of lager was first proposed by Nathan (1930)[…]”, referring to the now-ubiquitous style of metal fermenter seen in small brewpubs and “MegaBladderwashCo” large-scale industrial breweries alike. Based on this I had expected the reference to be a digression on the design, construction, and testing of the fermenter. When inter-library loan managed to get me a copy of the paper, I found something much more involved.

The paper is a presentation made by Dr. Leopold Nathan in 1930 to the Scottish section of the Institute of Brewing. The topic was not simply a fermenter design but the entire “Nathan System” of brewing which appears to be the basis of modern large-scale brewing, especially for Lager-type beers. At this point, Dr. Nathan had apparently already been developing this system for about thirty years (apparently starting with a German patent in 1908, which I’ve yet to find a copy of), so as you might guess it was not just a single invention but a whole collection of them. Compared to the more rustic techniques frequently in use at the time, the “Nathan System” of brewing promised to provide faster production, more consistent results, and a better final product. It does this mainly by improving the removal of “trub” (the cloudy bits of protein and such that settle out of the malt-water – the “wort” – after you boil it), preventing infection of the beer with undesirable organisms during the cooling, hops-infusion, and aeration, and by eliminating the need to “age” the brew to make it palatable. The most important improvement in the “Nathan Process” seems to be how he treats the wort between boiling and “pitching”.

—
For anyone unfamiliar with the brewing process, here’s a Grossly Oversimplified review of the steps:

Boil some malt-sugar dissolved in water to sterilize it and to help coagulate the “trub” proteins so they’ll settle out of the liquid.
Cool the malt solution and aerate it so that the yeast will grow in it.
“Pitch” your yeast into the now-cooled-and-aerated malt-water, in a container that will keep air out while letting out the carbon dioxide bubbles that the yeast will give of during the fermentation
Wait until the yeast get done fermenting, then put the resulting liquid into bottles/kegs/casks/whatever.

—

Diagram showing the containment vessel, cooling system, and sterile-air generator for the 'Nathan method' of brewing
I’ve added a couple of labels to that image from the paper, which I’m guessing was itself copied from a contemporary patent of Dr. Nathan’s. There are two purposes to this part of the Nathan Process – To cool and aerate the wort quickly without exposing it to risk of contamination, and to move trub and volatile sulfur compounds that would otherwise make the brew taste and smell funny. The hot boiled wort is pumped directly into an insulated vat (labelled “A” in the diagram) from the boiling kettle. At this stage the wort is hot enough to prevent anything from landing in it and growing. Then, the hot wort is pumped from the top of this vat into a clean-room containing a cooling device that the wort is poured on, cooling and aerating it as it flows through. Infection is prevented here by the fact that the room has a continuous stream of “sterilized” (or at least well-filtered) air, which is exhausted through the vent in the ceiling. The cooled, aerated wort is then pumped back out of the room and into the bottom of the insulated container below the still-hot wort.

Because of the large open cooling room with its constant stream of clean air, the cooling and aeration step also allows the volatile sulfurous compounds of “jungbukett” (The “Bouquet of Youth”; the unpleasant smells and tastes of immature beer, described in this paper as ‘onion-like’) to evaporate off and be carried away. Since waiting for these compounds to break down was apparently a primary reason for having to “age” lager before selling it, this not only improves the quality but eliminates the need to store the beer for months after fermentation.

The now-chilled wort then rests back in vat “A” and the trub settles out onto horizontal plates inside the vat, where it stays behind when the clarified wort is pumped out to the fermenters.

I did some poking around, and this appears to be what is described in US Patent# 1,581,194 (application filed in August of 1921), in case you are bored and want to look that up. If not, or if you don’t want to deal with the frustrating hassle of trying to view TIFF files in your browser, I intend to provide a followup post with some more details of the process and some interesting bits I found in it, and I’ll include a pdf of the patents, assuming anyone wants them.

Oh, one last thing – I’ve had no luck getting any biographical information about Dr. Leopold Nathan. Unfortunately when you search for “Leopold Nathan”, the results are clogged with references to a murdering smartass named “Nathan Leopold” instead. Doesn’t Google™ realize that brewmeisters are far more important than obscure murderers? No pictures of him, either, so I can’t even say whether his hairstyle is cooler than Eduard Buchner’s or not.

[1] Stanbury PF, Whitaker A, Hall SJ:”Principles of Fermentation Technology (2nd edition)”; 1995; Elsevier Science, Ltd; Tarrytown NY

I have a shocking confession to make.

I think I may be a nerd.

No, no, don’t try to deny it. I think it pretty much has to be true for someone who reads a 10-page scientific paper (hover or click here to see the reference) in order to learn that bacteria-snot is slimy. Yes, I am a nerd. And for that I am deeply, deeply….

Oh, who am I kidding? I like being a nerd.

For one thing, being a nerd allows me to fully enjoy one of the perks that my job gives me – namely access to a lot of scientific papers that I otherwise wouldn’t be able to afford to obtain access to from the greedy [insert your favority profanity here] who insist on charging $30 for permission to look at a decades-old articles for a day. I should add that this perk includes Inter-Library Loan for articles that I can’t get online, and the service on campus is great so far. Same day delivery of a classic article from 1930 in what I’m guessing most people would probably consider an obscure journal.

It doesn’t have quite the same thing in it that I expected from the source that pointed me to it, but I think it can still be considered “classic”. I need to re-read it more carefully to make a final decision on this, but I think I have my next “The Giant’s Shoulders” article in time for this month’s upcoming issue. And, yes, the picture attached to this post is a hint (and, no, it’s not directly related to the bacteria-snot article mentioned above in any way…)

The rightful place of science, and “The definition of an intoxicating beverage”

Just a brief point first: President Obama in his inaugural address promised to “restore science to its rightful place.” In traditional fashion, this prompted all manner of verbosity on blogs around the web concerning just what science’s rightful place actually is. Let me just take a moment to settle this question:

Science’s rightful place is kneeling at my feet in supplication and doing my bidding! AH, HA HA HA HA HA!!!!!

But that’s not what I came here to post about. Instead, I wanted to mention a paper I finally got my hands on. You may recall that some time back there were a few stories that popped up about what was said to be a “you can’t get drunk on beer” paper published back in the 1950’s. As usual, the people doing the reporting couldn’t be bothered to actually cite the paper in question, but I figured out which one it was. The paper is this one:
Greenberg LA:”The Definition of an Intoxicating Beverage”; Q J Stud Alcohol. 1955 Jun;16(2):316-25.

I have that paper. And I am quite disappointed in it in much the same way I was with Linus Pauling’s paper proposing a triple-helix structure for DNA. I did, though, learn some interesting things from Greenberg’s paper.

It turns out that the paper actually concerns the legal definition of “intoxication” and whether or not, based on this definition, beer should be classified as an “intoxicating beverage”. Greenberg actually raises some good points…but first, some amusement:

“The average alcohol content of American beers is 3.7 per cent[…]The strongest ale is 4.2 per cent” (page 320, paragraph 4)

Unfortunately, this isn’t quite as funny as it sounds, because the part I clipped out of that quote is where he says “by weight”. It’s still kinda funny though, since that would mean, in mass-market-bladderwash terms, that “The Strongest Ale” is Heineken.

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This Alcohol-by-Weight-vs-Volume issue may actually be part of why American beers have a reputation for having watery, feeble beers. It evidently used to be that places like Canada were using alcohol-by-volume, while the US was using alcohol-by-weight on their labels. An otherwise-identical beer bottled in Canada would have a higher “percent alcohol” on the label than the US-bottled version, making it seem as though the American version was weaker. So, evidently it’s not really true…things like “Coors Lite” notwithstanding. (See this recent page at Fermentarium.com for more details.)
—

But back to the point of the paper…evidently as Greenberg was writing this paper half a century ago, there wasn’t a clear, quantitative scientific or legal definition for “intoxication”. He points out that you can’t just define it in terms of alcohol merely having noticeable effects on the drinker, since the magnitude of the unpleasant effects at low to moderate drinking levels aren’t really much different than that for (for undesirable effects) lack of sleep, distraction [remember all those studies saying talking on the cell-phone while driving is as bad as being drunk?], hunger and so forth. For that matter, I think we can all see the problem of trying to arrest anyone who is being relaxed and amiable for “public intoxication”.

Greenberg solves this problem by looking at the average blood-alcohol concentration of people arrested for “intoxication” (0.21% back in the 1950’s, evidently), and a couple of previous studies from the 1920’s and 1930’s, and he finally settles on 0.15% Blood Alcohol Concentration as a level he’ll use as the line for “definitely intoxicated”. He then proceeds to go through the common classes of alcohol-containing beverages to determine how easy it is for someone to consume enough to reach this BAC.

In summary – For hard liquor, and average person would have to consume 8 ounces plus one ounce per hour of drinking (for example, 9 ounces consumed over the course of one hour). That’s not a difficult quantity to fit into a typical stomach, so hard liquor is obviously an “intoxicating beverage”. Fortified wines (like Port, Madiera…or Thunderbird): about 18 ounces plus 2 ounces per hour – say, a pint and a half in about 4 hours. Still pretty easy to do. An ordinary wine (like, say, a Gewürtztraminer): 36 ounces plus 4 ounces/hour – or a 7-11 “Super Big Gulp®”-sized portion in two or three hours. Getting to be a fairly substantial amount of liquid, but still plausible.

And then there’s beer. Greenberg comes up with a figure of 80 ounces + 10 ounces/hour. That’s roughly three quarts within one hour, which is quite a bit more than the approximately 2 quarts that a human stomach can hold. He goes on to describe several controlled experiments on beer consumption and the resulting blood-alcohol concentration. By pushing one group to consume a gallon and a half of beer over a period of 8 hours, they were able to get up to an average of just under “intoxicated” (by Greenberg’s definition) at 0.13%. The rate of beer ingestion required to pass the “intoxication” threshhold was more than most test subjects could even manage. Therefore (Greenberg concludes) beer should probably not actually be classified as an “intoxicating beverage”

Now for the party-poopery: Greenberg explicitly points out that this is certainly not the same as saying that beer cannot impair a drinker’s performance or judgement, so just because you haven’t consumed anything stronger than beer it doesn’t mean you should be allowed behind the wheel of a steamroller. Nor does it mean that it’d be okay for an alcoholic to drink beer (since an alcoholic is very unlikely to stop with just beer). Furthermore, these days “intoxicated” is legally about half of the level that Greenberg is using – 0.08% in most places in the US as far as I can tell. By Greenberg’s measure, you can easily get that amount of alcohol out of a pitcher of beer consumed over an hour.

So, Greenberg isn’t crazy, and beer can still make you drunk, just as we all would expect. How disappointing. Still, it’s an interesting paper and I’m glad I dug it up.

On a related note, if I can get my hands on an old paper from the Journal of the Institute of Brewing, I may have found my selection for February’s Giant’s Shoulders blog carnival. Stay tuned, more to come…

“Untersuchungen über Bacterien”

Once again I’m down to the last minute, trying to juggle too many things and almost missing this month’s “Giant’s Shoulders” blog carnival. Almost.

Today we go once again all the way back to the Victorian era, to see that if you thought bacterial taxonomy was difficult now, imagine what it was like over 130 years ago:
Cohn F:”Untersuchungen über Bacterien”; Beiträge zur Biologie der Pflanzen; 1875, vol 1; pp 127-222
(Or “Researches regarding Bacteria”, in “Contributions towards the Biology of Plants”)

This paper is an overview of the problem of categorizing bacteria among the types of living things, and makes some early suggestions. I don’t think it’ll spoil too much of the punchline to point out that not only is the journal about the biology of plants, but the paper also starts out with Cohn describing how he came to work at the “plant physiological institute”. Cohn’s assertion that bacteria are definitely a form of plant actually stuck for at least another three-quarters of a century or so – I have a copy of a 1945 book on bacteriology that actually has a short discussion on why bacteria are categorized as plants rather than animals (or “animalcules”, even). That’s only part of what’s interesting about this paper, though.

Cohn discusses a number of problems with the nature of bacteria in his time. For one thing, he says there had been little real effort to even come up with a coherent scheme for classifying bacteria at that point. He does mention one previous attempt to come up with a system, but on the whole it seems everyone is just coming up with terminology on the fly – even taking Pasteur himself to task for throwing around a variety of terms related to microbes without distinguishing what the terms actually refer to. The reason for this, really, is just that figuring out pretty much anything in detail about bacteria was a seriously difficult problem at the time. Cohn explains why; how it is really impossible to make out more than general shape and size from microscopic examination, and how the lack of any detectable sexual reproduction makes it impossible to do positively identify members of the same species. In fact, even very obvious differences in appearance might not be definitive. It was suspected (and later demonstrated) that some of what appeared to be completely different fungi were actually just different life-stages of the same fungus. (Hopefully you can see the picture at upper right, with the bacteria/yeast-like growth on one tube and the obvious and very different fuzzy mold-type growth on the other. Both are actually the fungus Blastomyces dermitiditis.) Just as some of Cohn’s contemporaries considered that perhaps all molds and yeasts were really just different stages of life of the same organism, perhaps the same might also be true of bacteria?

Cohn does, after all, promote the notion of bacteria as a type of fungus. You may even remember an old word for bacteria: Schizomycetes, that is “fission-fungi” (that is, fungi that reproduce by splitting in half rather than producing spores). This makes sense if you consider that bacteria are more like plants and algae than animals, and fungi were considered to be plants that lacked chlorophyll. Although lamenting that it was not feasible to really separate out individual bacteria to determine whether they ever changed form – this was still three years before Joseph Lister actually did so – Cohn unwaveringly felt that bacteria were in fact made up of several different genera and species, and set out an early attempt at classification.

Once again, Our Friend the American Society for Microbiology hosts a translation of this paper, complete with a couple of paragraphs of more modern editorial commentary at the end. It’s well worth a look.

Unfortunately, I don’t think Ferdinand Cohn’s hairstyle is nearly as spiffy as Eduard Buchner’s cool “Colonel Sanders Guest Stars on Miami Vice” look. I think he looks kind of like a slightly-better-fed Sigmund Freud with a bad comb-over. But that’s just me.

Obscure scientific papers, Mad Science, Travel, and other randomness

First – an amazingly astute observation that I’m ashamed to have not previously noticed myself (click image to go to it’s original site and see it full-size…):

I’m proud to say that I think testing Mad Hypotheses is great, and will continue to try to be a Mad Scientist. And a “Dirty Old Man” someday, but that’s a whole separate issue.

Second – I am really loving the perks of my new job – namely access to the college library system. I had previously mentioned (see last couple of paragraphs) a certain article that I wanted to get my hands on:

Greenberg LA:”The Definition of an Intoxicating Beverage”;Q J Stud Alcohol. 1955 Jun;16(2):316-25

Not only does the medical library have copies of a Czechoslovakian microbiology journal, the main library had a set of this old journal, too. I have my bedtime reading for tonight…

Thirdly – Another Giant’s Shoulders carnival has come and gone. I now believe that Eduard Buchner had hit upon not only a useful truth of living systems, but also a nifty alternative “mad scientist” hairstyle. Now I need to come up with one for next month. It’s been getting me thinking, though. That blog carnival is intended for “Classic” papers. Implied is that the papers are somehow important to the development of some scientific field or other. I’d like to see a variation on the “old papers” theme focussing on random old papers (where “old” might mean a few years or decades, depending on the subject) that people have found useful or interesting. Stuff that isn’t necessarily ground-breaking and has perhaps been forgotten or lost to obscurity but still has useful things to teach us. Naturally, I’m thinking especially Microbiology (and especially Microbiology other than Medicine) and Food Science. The Carnival could be called something like “Second Chance Science” or something of the sort. Just a thought.

Fourth – speaking of “Microbiology Other Than Medicine” and Food Science, apparently The National Academies of Science want to know what scientific topics people most want to read about. As usual, “microbiology” appears to have been relegated in their breakdown to merely a subset of either medicine/diseases, “biology”, and perhaps a small subset of “energy” and “Feeding the World” (no, seriously). The survey includes space to tell them what they’re missing – I heartily encourage anyone who cares to make sure you take the survey, and mention industrial and environmental microbiology and food science as subjects they shouldn’t continue to neglect.

And, finally – next week I need to make a very-long-overdue run back up to Idaho to grab some things from the old house and make sure it’s still standing, the water’s really turned off, nothing unnecessary is running, etc. 1600 miles of driving each way. Ugh. Anybody got any good recommendations for things to listen to on the trip? Other than having a chance to finally grab some things that I am missing, maybe I’ll at least have a chance to visit New Belgium Brewing Company again, since my route goes right past it. So long as I’m not driving by on Christmas day (when I assume they’ll be closed) I may have a chance.

“On the lactic fermentation and its bearings on pathology.”

Lunchtime – time to get this posted…(Let me know if this page is loading way too slowly…)

For this month’s “Giant’s Shoulders” I offer you mouthwash and yogurt.

Indirectly, at least.
Continue reading “On the lactic fermentation and its bearings on pathology.”

“A Proposed Structure for the Nucleic Acids”

Hello again, girls and boys and whatever else may be out there reading. It’s time once again for this blog’s contribution to The Giant’s Shoulders (hosted this time over at “Second Order Approximation“). This month I’m looking at something even smaller than usual. Inspired by my new job in the biochemistry department where they seem to do a substantial amount of X-ray crystallography (which I do not – yet – understand as well as I’d like), I thought I’d drop all the way down to the molecular level and talk about a fundamental discovery that helped make modern molecular microbiology possible: the structure of DNA.

Yes, it was over a half-century ago that an accomplished scientist, working with X-ray images produced from crystallized nucleic acids, published the first proposed structure for for them – the famous Triple Helix.

Continue reading “A Proposed Structure for the Nucleic Acids”

Possible audio show, and “ask me anything!”…

You may be wondering where I’ve been. (If not, in order to spare my fragile little ego, please pretend that you were. Thank you.) Well, mostly I’ve been in my car driving to and from my spiffy new job.

This hasn’t left me with much time to blog lately, which annoys me a bit. On the other hand, the commute is long enough that I run out of netcasts to listen to during the week, leaving me with driving time back and forth during which I could conceivably be doing something productive.

Continue reading Possible audio show, and “ask me anything!”…

Phylogenetic structure of the prokaryotic domain: the primary kingdoms.

Ike’s comin’ right for us, so I don’t know when the my power and internet access will die, and if so how long it’ll be before it comes back. However, while I’m still connected I wanted to contribute something again to this month’s The Giant’s Shoulders blog carnival. Since it’s in three days and there’s a chance our power might be out when the deadline passes, I figured I’d better hurry. Because of the hurry there are no fancy graphics nor even too much explanatory text here, but I’ll do what I can. Fortunately, the basics of today’s post isn’t too complex.

Depending on how rigorous your biology education was, there are a variety of ways that you might tend to categorize the fundamental types of living things. You might vaguely recall something about “five kingdoms”, which as I recall were “Animals, Plants, Fungi, Protozoa [e.g. amoeba], and Bacteria”. You might just segregate everything into either “animal” or “plant”. If your memory of biology education is a bit stronger, you might remember that “bacteria” are a separate group from the true plants and animals. A step more precise and you may split living things into the two domains of “prokaryote” and “eukaryote”.

The “plant” and “animal” distinction is pretty classic – until comparatively recently, bacteria were assumed to be “plants”, just as fungi (“plants” that lacked chlorophyll) were. Non-photosynthetic bacteria were referred to as “schizomycetes” (literally “fission” [splitting in two] fungi, because they reproduce by splitting from one cell into two rather than forming spores), while bacteria with chlorophyll (cyanobacteria or “blue-green” algae, and possibly the “green sulfur bacteria”) were designated “schizophyta” (“fission plants”).

Within the last fifty years or so, though, it’s become obvious that bacteria were a different type of life from fungi, chlorophyll-containing plants, or animals. The latter critters have cells that in turn contain “organelles”, which are more or less very specialized “mini-cells” within themselves. The nucleus, for example, is a compartment within the cell where the cell’s DNA is kept and processed. Bacteria, it turned out, don’t have any of these organelles (in fact there’s good evidence that at least some if not all organelles used to be bacteria, but this post’s long enough already so I won’t go into that), and life was re-organized into the bacterial “prokaryotes” (“before nucleus”) and the “eukaryotes” (having a “true nucleus” – i.e. everything that isn’t bacteria).

Then, along comes Carl Woese, who spoils this nice simple dichotomy. In 1977, he published (along with G.E. Fox) the subject of today’s post:
Continue reading Phylogenetic structure of the prokaryotic domain: the primary kingdoms.

It’s comin’ right for us!

(Click image for Wunderground.com’s interactive “Wundermap”…)

Actually, looking more closely at the picture there I think we may be slightly further west than it indicates, but it’s still very likely we’ll end up losing power for a while sometime tonight, but I still am going to try to get a post up for the Giant’s Shoulders blog carnival – I’ve got the paper picked out and read, I just need to do a write-up before I go to bed tonight. Currently it looks like the winds shouldn’t get TOO bad until late tonight/early-tomorrow-morning so we ought to have power long enough…

Yes, there’s a disturbingly severe hurricane “Comin’ right for us!” and I’m worrying about posting about a classic scientific paper before the blog-carnival deadline while I still have power. How’s THAT for dedication?

First we need to move stuff inside, though. I don’t want The Ascospore getting blown away…