I get a fair number of emails these days related to beer and alcohol, many of which are press releases of various types, but occasionally one arrives that’s offbeat and interesting. Case in point: a pointer to this article on Botulism from Drinking Pruno from the US National Library of Medicine. I found this fascinating particularly from an Apocalypse Beer standpoint.

Pruno, in case you didn’t know, is the name given to “prison wine” brewed illegally using whatever ingredients are on hand (typically fruits, ketchup, bread, and so on). It’s arguably nasty but not normally poisonous, but this article examines several cases from California from 2004 and 2005 where botulism did in fact sicken prison inmates. It details the making of pruno (in these cases) as well as more information than you probably realized on the types and sources of botulism out there.

Some quotes:

From information gathered, one of the hospitalized inmates began making the pruno on June 21 using “unpeeled potatoes smuggled from the kitchen, apples from lunches, one old peach, jelly, and ketchup.” On June 25, this inmate “heated water with an immersion heater and added it to the mixture.” Correctional officers estimated that ≈2 gallons of pruno were made. On June 27, each of the 4 inmates drank ≈16 ounces or more of the pruno, which they described later to a prison nurse as being “magenta in color” and “smelling like baby-poop.”

In May 2005, DCDC was notified of clinical botulism in another inmate of another California state prison in Monterey County. Upon further questioning, the patient admitted to making and drinking pruno in the prison; he had used potatoes in making the pruno. Pruno mash was found in his cell, and culture at MDL yielded C. botulinum that produced toxin type A.

In our investigations, the potatoes used in the pruno could have been the source of botulinum toxin. C.botulinum is commonly found in the soil, and its spores have been found on raw potatoes. Several outbreaks of botulism caused by eating potatoes have occurred in the United States, and laboratory studies have shown that C. botulinum spores on the surface of raw potatoes can survive baking and lead to production of botulinum toxin. The warm anaerobic fermentation process of making pruno probably predisposes toward production of botulinum toxin, particularly if any ingredient happens to be contaminated with C. botulinum or its spores, such as the potatoes used in these 2 instances.

Pruno is popular in prisons across the country, and it is somewhat surprising that botulism caused by pruno consumption has not been previously reported. This lack of reporting may be due to the fact that potatoes are not generally used in the making of pruno; recipes for making pruno and references to pruno found on the Internet do not mention potatoes as an ingredient.

Besides a fascinating look into the brewing of prison hooch, the takeaway here is, apparently raw or even baked potatoes can be a source of botulism (which is kind of concerning on a number of levels!) so if you’re going to brew with them make sure to treat them properly. (And don’t let them sit around in a warm, anaerobic environment.)

Bonus: This NPR story highlights more recent cases, also caused by potatoes.