Woo Alert: Beer Line Magnets


Best bit of pseudoscience we’ve had in the office so far this week: “how often should beer lines should be cleaned if a magnetic beer line cleaner has been fitted?” Answer: Just as often as before as before as these devices only clean out your wallet. København

This is a novel twist on the magnetic water softener scam (hint: useless) and it’s claimed pubs can save money because beer lines need cleaning far less frequently. The basic claims are that magnets prevent yeast and other detritus sticking to the lines, and therefore increase the time between cleaning. Each time you clean a beer line that’s 3-4 pints wasted so if you do it monthly rather than weekly that’s a good few quid saved – but the process is vital to stop oxalates and other scale building up and to help prevent microbial spoilage of the beer.

OK. Some bacteria are magnetotactic (can sense and respond to a magnetic field) but not yeasts (on both counts; they are neither a bacterium nor magnetotactic). But lack of basic scientific plausibility doesn’t get in the way of some quite inventive claims we found with a quick trawl of the Interwebs:

“The magnetic field applied to the liquid through the wall of the pipe has an ‘ionisation’ effect on the liquid. This makes it harder for any particles in the liquid to stick to each other or to the inside of the pipe.”

The notion that a magnet can ionise beer (or water) is utter twaddle. You can’t ‘ionise’ either. You can add ions to water or to beer but not with a bleedin’ magnet. Water found in nature tends acquire ions such as calcium and bicarbonate as it comes into contact with rocks and sediments. Beer will have other ions too but no magnetic device is capable of increasing these ion concentrations Same as magnetic ‘water softeners’. You can’t soften water or clean a beer line with a magnet. This is what we scientists term “Utter, Utter Bollocks” (U²B). We’ve come across magnetic water softeners before (U²B) so we looked at a few beer line systems:

“Ultrasound waves at low frequency… ‘excite’ the yeast molecules in the beer and prevent them from clumping. Therefore there are less yeast clumps to form on the beerlines and the line cleaning schedule can be reduced from weekly to monthly.”

Yeast molecules? Sheesh. AND IT’S FEWER, NOT LESS.  They add:

“The ultrasound waves that are produced are in the range <15 KHz and are ramped from a base frequency level, through a predetermined time period. This ramping of the ultrasound pulses is an integral part of the patented process as it creates the optimum conditions for the process of cavitation to occur.”

15kHz isn’t low frequency by a long chalk and yes, it will cause cavitation on a micro scale. My fear here would be that it is likely to cause sonic lysis (breakdown) of the yeast cells as well as any other bacteria. In a micro lab you usually sonicate at 20kHz but it will work at lower frequencies depending on the organism). Apart from sonic lysis of microorganisms making putrefaction more likely, if there are any Gram negative bacteria lurking, sonicating the lipopolysaccharide coat (endotoxin) could make people ill. But it is likely the beer would be noticeably unpleasant before it got to that state, though.

This same system at least makes a good effort at some plausible-sounding stuff until claiming:

“…impossible to mimic precisely the conditions pertaining to the installation of the… System in a working cellar’s beerlines. It was necessary to construct a system that could not only be used in the laboratory but also cleaned (i.e. sterilised) regularly.”

U²B. It is actually a very easy experiment to design in situ – all you do is run a bunch of pipes with and without the repurposed fridge magnets attached, then put a proper beer line cleaner (not the purple stuff) through and study the UV absorption of what comes out. (This is a standard, easy way to measure protein concentration – proteins absorb UV well at 280nm). Using protein concentration as a surrogate for yeasts and other biological crud will give a very quick idea of how much muck is in the line and if the Magic Fridge Magnet has worked you’d expect what comes out of those lines to absorb less. Cos it’s got less crud in. Seemples, as that nice anthropomorphic meerkat on the telly would say.

The other flaw with the ‘data’ they give is they use Candida utilis rather than Saccharomyces in their in vitro study. While both are yeasts – sort of – Saccharomyces and Candida are very distinct biologically and behave very differently, notably in their ability to stick to stuff. An in-vitro study on one does not mean you can make similar claims regarding the in situ behaviour of an entirely different organism. But that’s just me nit picking – that design flaw would be a concern if what they were studying is a real phenomenon rather than Tooth Fairy Science (see this post for an explanation of that).

Some claims are truly breath-taking:

“Continious [sic] EM field generates ion clusters throughout the beer line system (unlike other magnet based systems) causing clustering of charged particles and preventing attachment to beer lines. Induced high frequency current (in this case in beer), Bio film is reduced and in some cases prevented completely by the “skin effect” – whereby the current density near the surface of the conductor is far greater than at its core. This prevents bio film growth. As bacteria pass through the ferrite ring they receive a charge, which causes hydration and the cells effectively destroy themselves through reverse osmosis.”

While I understand all the individual words in this paragraph when taken as a whole it is, as we say in the trade, gibberish. It’s  U²B. It’s actually quite difficult to form a reasoned, evidence-based response to this twaddle. As Thomas Jefferson said on an entirely different subject: “Ridicule is the only weapon that can be used against unintelligible propositions. Ideas must be distinct before reason can act upon them.”


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