Copper naturally sanitary?

[Black Island Brewer]

I was brewing this weekend with a brewer who works in a medical lab, and she said something that caught my interest: she said that clean copper is naturally sanitary, that it is one of two metals that microflora cannot live on, the other being silver. Has anyone else heard this before? I'd love to be less anxious about boiling my immersion chiller prior to chilling...

 

[day_trippr]

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

That said, it isn't all peaches and cream. If your copper grows green, that's bad, okay?

Cheers!

 

[Mindsculptor]

It's not true. People that run water cooling systems in their computers tend to keep small coils of pure silver in their water reservoirs to suppress the growth of algae. Note that water blocks and radiators, at least the quality ones, are copper.

EDIT: I didn't think of viruses when you posted this. Needless to say, copper doesn't kill algae and it doesn't kill yeast or a whole host of similar things. Silver is the only universal killer of single celled organisms.

 

[helibrewer]

Copper will also promote oxygen radical formation since it is a transition metal ion so keep copper to a minimum in the brew house....it's only used for show in the big houses.

 

[MindenMan]

Copper is not just for show. Why do you think moonshiners made their equipment out of copper? Copper on a molecular level, stops the formation of rhino farts by ionic exchange.

 

[Mindsculptor]

Because stainless wasn't available, regular steel would rust, and porcelain doesn't mix well with back woods hills.

 

[JaDeDBrewing]

It's not true. People that run water cooling systems in their computers tend to keep small coils of pure silver in their water reservoirs to suppress the growth of algae. Note that water blocks and radiators, at least the quality ones, are copper.

EDIT: I didn't think of viruses when you posted this. Needless to say, copper doesn't kill algae and it doesn't kill yeast or a whole host of similar things. Silver is the only universal killer of single celled organisms.

All of the following articles are referring to dry copper surface contact.

"Bacteria, yeasts, and viruses are rapidly killed on metallic copper surfaces, and the term “contact killing” has been coined for this process. While the phenomenon was already known in ancient times, it is currently receiving renewed attention. This is due to the potential use of copper as an antibacterial material in health care settings. Contact killing was observed to take place at a rate of at least 7 to 8 logs per hour, and no live microorganisms were generally recovered from copper surfaces after prolonged incubation. The antimicrobial activity of copper and copper alloys is now well established, and copper has recently been registered at the U.S. Environmental Protection Agency as the first solid antimicrobial material. In several clinical studies, copper has been evaluated for use on touch surfaces, such as door handles, bathroom fixtures, or bed rails, in attempts to curb nosocomial infections."

Source: http://aem.asm.org/content/77/5/1541.abstract

"On February 29, 2008, EPA registered five copper-containing alloy products. The registration allows the registrant, the Copper Development Association (CDA) to market these products with a claim that copper, when used in accordance with the label, “kills 99.9% of bacteria within two hours.” This Web page explains the conditions of the registration and provides information on the pesticidal claims."

Source: http://www.epa.gov/pesticides/factsheets/copper-alloy-products.htm

Definition of pesticidal from the EPA: "Antimicrobial pesticides are substances or mixtures of substances used to destroy or suppress the growth of harmful microorganisms whether bacteria, viruses, or fungi on inanimate objects and surfaces."

Source: http://www.epa.gov/oppad001/ad_info.htm

"Metallic copper surfaces kill microbes on contact, decimating their populations, according to a paper in the February 2011 issue of the journal Applied and Environmental Microbiology. They do so literally in minutes, by causing massive membrane damage after about a minute's exposure, says the study's corresponding author, Gregor Grass of the University of Nebraska, Lincoln. This is the first study to demonstrate this mechanism of bacteriocide.

"When microbes were exposed to copper surfaces, we observed contact killing to take place at the rate of tens to hundreds of millions of bacterial cells within minutes," says Grass. "This means that usually no live microorganisms can be recovered from copper surfaces after exposure."

Thus, such surfaces could provide a critical passive defense against pathogens in hospitals, where hospital-acquired infections are becoming increasingly common and costly, killing 50,000-100,000 Americans annually, and costing more than $8 billion, according to one estimate. Still, Grass cautions that "metallic copper surfaces will never be able to replace other hygiene-improving methods already in effect," although they "will certainly decrease the costs associated with hospital-acquired infections and curb human disease as well as save lives." However, he expects this strategy to be inexpensive, because "the effect does not wear off."

Critically, the researchers provide strong evidence thatake genotoxicity through mutations and DNA lesions is not a cause of dry copper's antimicrobial properties. This is important, because mutations can cause cancer in animals and humans, and the lack of such mutations in bacteria from copper means that copper does not endanger humans.

The relevant experiment was particularly interesting. The bacterium, Deinococcus radiodurans, is unusually resistant to radiation damage, as its DNA repair mechanisms are especially robust. The hypothesis: if metallic copper kills by causing DNA damage, D. radiodurans should be immune to copper. It is not.

It is important to note that only dry copper surfaces are amazingly lethal to bacteria. The difference between dry and wet surfaces, such as copper pipes, is that only dry surfaces are inhospitable environments for bacterial growth. Bacteria can easily grow and reproduce in wet environments, and in so doing, they can develop resistance to copper. Resistance has not been observed to develop on dry copper surfaces."

Source: http://www.sciencedaily.com/releases/2011/02/110216120436.htm

Please understand that we here at JaDeD Brewing are not out to disparage, belittle, or to talk down to our fellow homebrewers. The information above is not well known and can be very useful.


Cheers!

 

[Hockeyman]

It is important to note that only dry copper surfaces are amazingly lethal to bacteria. The difference between dry and wet surfaces, such as copper pipes, is that only dry surfaces are inhospitable environments for bacterial growth. Bacteria can easily grow and reproduce in wet environments, and in so doing, they can develop resistance to copper. Resistance has not been observed to develop on dry copper surfaces."

So dry off your equipment and no bacteria will grow...