Friday, January 4, 2013


That Old Time Butcher's Block !
Remember those old time butcher blocks behind most all meat counters ? One day in the early 1990s, some new science based study suggested to the Government that they all had Coodies. Hence, at least in California, all commercial establishments had to rid themselves of those evil wooden cutting boards or be fined, shut down or both. What a sham that was and yet, there was a few University studies that revealed otherwise. That however didn't matter. A government mandate was the order of the day and the old time wooden butcher block was out. 

I remember when I owned and ran my gourmet bakery distribution business in western Riverside County. All of the restaurants I served with specialty breads in 1992 were moaning over the new law which forbid them to use wooden cutting boards in their restaurants and Butcher Shops. Some of these Butcher's Blocks were a few decades old and never a problem. Suddenly some genius comes up with the idea that wood must be unhealthy and therefore new scientific innovations in the world of plastics certainly were far superior. I remember stopping by Cahuilla Market and conversing with owner Chuck McKee who owned the Market and Deli he and his wife Jackie had just opened. He didn't much like government regulations anyway and this was one more irritation under his belt. In 1993 I found a study that was produced by the University of Wisconsin which proved wood was far far safer than the plastic cutting boards. Come to find out, wood does have antibacterial properties which bacteria cannot live on or in. Chuck brought this up to the Health Inspectors attention a couple of weeks later, but it feel on deaf ears. She said she and her supervisors had read the study and the results of their findings, but they were not budging on their opinion of no wood plastic only rules. Chuck was furious, but could do nothing.

Recently I was preparing some vegetables on our plastic cutting board and have always been conscious of super cleaning it with soap, alcohol and hot water with a brush after using each time. I remembered this study and thought I'd remind everyone who may or even may not have known about this incredible study. As time passes you forget just what is important as far as food safety, even though you may have read these before. The first is that paper from the University of Wisconsin. Pay attention closely to this report. It is both education, even if it's a refresher for some, and humorous in exposing what was conventionally thought. 


"We began our research comparing plastic and wooden cutting boards after the U.S. Department of Agriculture told us they had no scientific evidence to support their recommendation that plastic, rather than wooden cutting boards be used in home kitchens. Then and since, the U.S. Department of Agriculture's Meat and Poultry Inspection Manuel (official regulations) and the U.S. Food and Drug Administration's 1999 Food Code (recommended regulations for restaurants and retail food sales in the various states of the U.S.) permit use of cutting boards made of Maple or similar close-grained hardwood. They do not authorize specifically acceptable plastic materials, nor do they specify how plastic surfaces must be maintained."
"Our research was first intended to develop means of disinfecting wooden cutting surfaces at home, so that they would be almost as safe as plastics. Our safety concern was that bacteria such as Escherichia coli O157:H7 and Salmonella, which might contaminate a work surface when raw meat was prepared, ought not remain on the surface to contaminate other foods that might be eaten without further cooking, We soon found that disease bacteria such as these were not recoverable from wooden surfaces in a short time after they were applied, unless very large numbers were used. New plastic surfaces allowed the bacteria to persist, but were easily cleaned and disinfected. However, wooden boards that had been used and had many knife cuts acted almost the same as new wood, whereas plastic surfaces that were knife-scarred were impossible to clean and disinfect manually, especially when food residues such as chicken fat were present. Scanning electron micrographs  revealed highly significant damage to plastic surfaces from knife cuts."
"Although the bacteria that have disappeared from the wood surfaces are found alive inside the wood for some time after application, they evidently do not multiply, and they gradually die. They can be detected only by splitting or gouging the wood or by forcing water completely through from one surface to the other. If a sharp knife is used to cut into the work surfaces after used plastic or wood has been contaminated with bacteria and cleaned manually, more bacteria are recovered from a used plastic surface than from a wood surface."
"Manual cleaning" in our experiments has been done with a sponge, hot tapwater, and liquid dishwashing detergent. Mechanical cleaning with a dishwashing machine can be done successfully with plastic surfaces (even if knife-scarred) and wooden boards especially made for this. Wooden boards, but not plastics, that are small enough to fit into a microwave oven can be disinfected rapidly, but care must be used to prevent overheating. Work surfaces that have been cleaned can be disinfected with bleach (sodium hypochlorite) solutions; this disinfection is reliable only if cleaning has been done successfully."
"These experiments described have been conducted with more than 10 species of hardwoods and 4 plastic polymers, as well as hard rubber. Because we found essentially no differences among tested wood species, not all combinations of bacteria and wood were tested, nor were all combinations of bacteria and plastics or hard rubber. Bacteria tested, in addition to those named above, include Campylobacter jejuni, Listeria monocytogenes, and Staphylococcus aureus."
"We believe that the experiments were designed to be properly representative of conditions in a home kitchen. The may of may not be applicable to other plastic and wooden food contact surfaces or to cutting boards in commercial food processing or food service operations, but we have no reason to believe that they are not relevant, except that not all plastic surfaces are subject to knife scarring. Before our first studies had been published, they were criticized incorrectly for not having included used (knife-scarred) cutting surfaces. We had been careful to include used surfaces, and so were surprised that others who did later experiments and claimed to have refuted our findings often had used new plastics and wood. Although some established scientific laboratories say their results differ from ours, we have received multiple communications from school children who have done science projects that have reached essentially the same conclusions that we did."
"We have no commercial relationships to any company making cutting boards or other food preparation utensils. We have tested boards and cleaning and disinfection products, some of which were supplied to us by gratis (free or gift). We have not tested all of the products that have been sent to us, simply because there is not time. We are aware that there are other food preparation surfaces made of glass or of stainless steel; we have done very little with these because they are quite destructive of the sharp cutting edges of knives, and therefore introduce another class of hazard to the kitchen. We believe, on the basis of our published and to-be-published research, that food can be prepared safely on wooden cutting surfaces and that plastic and that plastic cutting surfaces present some disadvantages that had been overlooked until we found them."
"In addition to our laboratory research on this project, we learned after arriving in California in June of 1995 that a case-control study of sporadic salmonellosis had been done in this region and included cutting boards among many risk factors assessed (Kass, P.H., et al., Disease determinants of sporadic salmonellosis in four northern California counties: a case control study of older children and adults. Ann. Epidemiol. 2:683-696, 1992) The project had been conducted before our work began. It revealed that those using wooden cutting boards in their home kitchens were less than half as likely as average to contract salmonellosis (odds ratio 0.42, 95% confidence interval 0.22-0.81), those using synthetic (plastic or glass) cutting boards were about twice as likely to contract salmonellosis (O.R. 1.99, C.I. 1.03-3.85); and the effect of cleaning board regularly after preparing meat on it was not statistically significant (O.R.1.20, C.I. 0-54-2 68). We know of no similar research that has been done anywhere, so we regard it as the best epidemiological evidence available to date that wooden cutting boards are not a hazard to human health, but plastic cutting boards may be.
January 21, 1993
CONTACT: Dean Cliver, (608) 263-6937 
This research was also republished by University California Davis in the link below here:
"Plastic and Wooden Cutting Boards, by Dean O. Cliver, PhD
Credit: Photoholic1

Artwork Cutting Board 
I loved reading this piece all over again and it triggers some thoughts about how things get done or not in our modern world. Despite the championing of science as that ever wonderful ever improving animal, there are some very real concerns to consider. Science is only as good and honest as those who participate. Researchers can be honest, conscientious, and disconnected to any bias or they are shackled to the big politics & corporate business special interests that hire them. As stated in paragraph #6, they were criticized by other Labs who claimed they didn't get the same results. They were accused of not using older cutting boards for the experiment. Further investigation revealed those other Labs used brand new cutting boards, and yes reached the same conclusions as Dean Cliver's study on new cutting boards. Plastics performs wonderfully when there are NO KNIFE SCARS. Gee, who wouldda thunk it ? 

Next, they had to emphatically make it clear that they had no commercial ties to any commercial producers of any products. For example *cough-cough* Weyerhaeuser Corporation, etc, etc, etc. Next, and I love this one, they also were contacted by Schools where kids and come to the same exact conclusions as they did in their Science Fair Projects. Now why was that ? How could an inexperienced child come to the same conclusions as the above study, that a high paid Lab employee with much coveted initials behind their last name couldn't even come close to ? Because kids are not shackled by big corporation interests or political dirty deals. Kids while still young have a keen innocent interest in learning and discovery and believe that is what science is all about. Too bad they have to grow up and learn the truth about how the real adult world works. As far as I know, California still doesn't allow wooden cutting boards in commercial kitchen operations. Everything is business as usual. Fortunately, Government arms don't stretch as far as the personal home kitchen, yet! Still, how much bacterial out break in commercial operations have been the result of ignoring this study ? These bacterial outbreaks have been on the increase if you have paid attention to the News Reports the last couple decades since that study. 

There are several things to keep in mind. Remember the type of wood they said worked the best. You need hardwoods like Maple, etc. The reason is obvious. Cutting boards get abused by knife cuts, all boards do anyway. Cuts on hardwood will not be as deep as if you use one home made of pine. Also, remember that bacteria were found in the pores of wood, even though they didn't multiply and even died before cleaning. Wood actually has natural antibacterial properties, but that still doesn't mean you can neglect cleaning hygiene of your kitchen. The University of Wisconsin researchers said they were given all sorts of freebies from manufacturers no doubt of cleaning products. But most safe products will work and sterilize. Given the safer properties of wooden boards over the Polyethylene Plastic boards, you may even be able to dump the more risky chemicals and opt for safer ones. Still, don't be lazy, cleaning should always be done immediately after use to ensure safety. Also keep in mind what modern plastics are made of and the danger in chemical leaching of nonylphenols and Bisphenol-As. - See: "Our Stolen Future" research website

Interestingly, I have stumbled upon some modern sites, especially some Culinary Arts websites which demonize and make little of the research that was done by Dean Clive. As an example, the study they cite  (Here)  and criticize is actually a Science News article written by a Reporter which came out a month after the University Press Release on February 6, 1993 and not the actual University Study I linked to from the U.C. Davis and the University of Wisconsin. Reporters tend to exaggerate and embellish on things that excite them. Rarely are they corrected. Only in this instance were there only critics to be found. One of the accusations was that it was later found that there were live bacteria in wood pores. Funny, in the University study they admitted that, but that unlike the plastic boards, they were incapable of multiplying, but eventually died. The Science News magazine didn't reveal this, the actual study however did. They also omit the independent other study in California of the Salmonellosis outbreaks which revealed that 50% of those using the wood were LESS LIKELY to be infected and 50% more of those using Plastic were MORE LIKELY to be infected, and again, that study had nothing to do with Dean Cliver's study. It only confirmed his findings. I hate biased dishonest Profit motive science and this is a clear case. What I do know is that many popular Culinary Arts and other Food websites do have sponsors to please. You figure it out and decide what ultimately you personally will choose. Despite such good any and all credible studies back by good science, remember this about the world & system that actually rules in real life and that little thing called the  "Golden Rule"
"Remember the 'Golden Rule', the one with the 'Gold' makes the Rules"
Although attractive designer boards are everywhere and kool looking, make sure they are made of the correct type of hardwood which will have tinier pores. Below is a good video of how to properly clean your cutting board with TV Cooking Host personality, Rachael Ray. Also another interesting video on maintenance I enjoyed.

Further Reading Info:University of Florida: "Bacteria on Cutting Boards"
This next link is from a 2008 study from the Hospitality Institute of Technology and Management who, utilizing fluorescent powder which by it's tiny size and particle diameter represent to almost identical size of a bacterial organism. If you've ever noticed, staining is tougher to get out of plastic boards than wood, which should illustrate something to you.
BERNARD LEVINE'S KNIFE LORE - Wood versus Plastic Boards

The Antibacterial Effect of Wood
Wood Boards Effecting the Survival of Bacteria ?
Antimicrobial Properties of Heartwood, Bark/Sapwood and Leaves of Juniperus species
Switzerland: "Wood - An Effective Bacteria Killer" (2005)


  1. Very interesting! We have both here at home and I HATE the plastic ones...Now I have a good reason to hate them! :-)

    1. This Dean Cliver has an interesting history. Sadly he's dead now, died in 2011. People like him take their knowledge and experience with them. You know, not everything gets recorded on paper. In his career at UC Davis, he was one of the first to deal with Mad Cow Disease. That was a disease created as a result of the Bad Science-Based innovation of grinding up dead animal protein and manure and mixing it with regular feed and feeding it back to Herbivores. I'm sometimes amazed that this planet still functions at all.


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