Brewing with vintage malt extracts

Zymurgy
1

In this recent article, the author briefly mentions the rumor of botulism being a concern with old LME, but he goes into no further detail as to the validity of this rumor. 
Does anyone else find it odd that he does not try to research this a little further?  It seems like a rather important issue if it’s even remotely true.

I also found it odd that he devotes a large part of the article to the theory that FAN diminishes in malt extract over time.  But his correspondence with Coopers and Alexander’s says that FAN does not diminish over time.
Does anyone else feel he devoted a large portion of the article to a non-issue?

However, I did enjoy the spirit of the article and the recipe.  I have several bulged cans of LME at home that I may some day crack open for my old “Old Bulger”… assuming it’s medically safe to do so.

2

yeah, that kind of stood out to me … “hey cans like these could have botulism which is deadly” … and then nothing

I wouldn’t take the risk, I don’t think wort is acidic enough nor boiled long enough to kill botulism spores

3

I believe I have read that the boil will kill the spores, but may not denature/dissipate the toxin that the spores produce.

I have seen “experts” go round and round on the subject so I found it odd that this author was so blasé about it.

4

I could be wrong, but it seems to me that the very process of canning the extract would take care of any spores.

Outside of that, it’s been quite some time since I brewed from extract but do remember doing a batch many years ago using extract that was past it’s prime.  I’m still here to tell about it.  The resulting beer, however, was definitely sub par.  Safe to say that old extract may not kill you, but will almost guarantee a finished beer with some off flavors.

5

A swollen can has many potential causes.
http://www.fda.gov/Food/ScienceResearch/LaboratoryMethods/BacteriologicalAnalyticalManualBAM/ucm109398.htm

Botulinum toxin is formed by C. botulinum endospores under anerobic conditions.  It dosn’t necessarily cause the can to swell.

As long as you boil the extract >3 minutes, you shouldn’t have to worry about the botulinum toxin (even if it is present).
If you dump the extract straight into the fermenter w/o boiling, then you run the risk of botulism.

http://en.wikipedia.org/wiki/Botulism

6

If you have a large pressure cooker/canner, you could high temperature treat the cans prior to use.  This would kill any botulism toxin.

7

A few years ago I used LME that was at least 4 to 5 years past its expiration date, cans that I had kept down in my basement and forgotten about.  It was one of those times when I had quit brewing for a few years.  Anyway, when I started brewing again I was buying new cans but wanted to try steeping some grains, then doing a partial etc.  The only one that didn’t turn out was one I had added cherry syrup to a dark stout.  It was probably fine, I just didn’t like the taste.  I’m still here… maybe I’m a little touched though eh?  :smiley:

Maybe doing a partial or mini-mash would help with any FAN issues?