In the realm of commonly-held but not entirely accurate understandings around food safety, the discussion of which is safest to use in the kitchen, be it glass, plastic, silicon, steel, or wood, is apparently a very contested subject. Mainstream anti-bacterial teaching holds that plastic is safer than wood, that steel is safer than plastic, and wood is put at the bottom of the safety pile. My recent foodsafe training from the province of BC Canada states very intensive, completely unnecessary methods for attempting to make wood foodsafe, ostensibly from the above misguided knowledge.
In the USA, the same kind of misinformation has been taught, with one researcher in 1993 sharing:
Government foodsafe guidelines have either informed the knowledge of woodworkers out there, or their lack of anti-bacterial knowledge around their favourite crafting material has informed governments. I’m not sure which way that goes, but many woodworkers are making claims about the safety of wood in the kitchen that doesn’t reflect what scientists have discovered about the anti-bacterial nature of wood. One researcher did a simple wood-finish test between mineral oil and linseed oil in comparison to unfinished wood, that is an eye-opener as well.
Growing up in a logging/mining/fishing town meant learning about the anti-bacterial and anti-fungal nature of Cedar for example, as fence posts and pilings made from this wood would last literally decades before they broke down and disintegrated. The volatile oils present in Cedar are strong enough to cause adverse effects in biological systems, making them unsafe for human consumption. The only other wood to my current (as of early 2025) knowledge that comes close in the “poisonous” category, is the Yew tree, also a conifer. Don’t eat the Cedar or Yew, therefore, it bothers me to see cedar planking sold for use with smoking or bbq’ing meat! It isn’t the bacterial transference that bothers me, those trees will kill that bacteria very well. It’s what those oils will do in the human body that bother me.
The currently promoted misinformation around the safety of wood in the kitchen is best shown in the discussion, or should I say conflict, around oak, whether we’re talking red or white oak. Due to the concept that bacteria need to be humanly washed away using things like bleach, hydrogen peroxide, iodine, vinegar or lemon juice, the idea that the bacteria may be pulled into the wood where they die, is lost on most wood workers who claim to have years of experience creating safe wooden tools for the kitchen. The common claim is that the highly porous nature of red oak makes it unsafe. The closest anyone has come to explaining this logically, is that if you are using the planed or flat side of the wood, food can get stuck in the pores, they’re that large. Some people have actually been able to take a block of red oak, and blow bubbles with it! Does this really make red oak unsafe in the kitchen?
If you are the type to believe that if a human didn’t do it, it’s not done, then you’ll answer a resounding YES, because YOU can’t wipe off most of the bacteria, therefore it must be a foodsafe hazard! Nothing could be further from the truth. We’ll now look at several papers spanning the past 30+ years.
In 2020, a paper published to PubMed, a division of NIH in the US, set about to identify various methods by which bacteria can be tested for in wood materials. They were coming from a mainstream misinformed position as they wrote the following:
“Some wood species have antimicrobial properties, making them a better choice over inert surfaces in certain circumstances. However, the organic and porous nature of wood raises questions regarding the use of this material in hygienically important places. Therefore, it is reasonable to investigate the microbial survival and the antimicrobial potential of wood via a variety of methods.”
This paper tabulated their 57 sources’ results, showing various woods being mentioned for various levels of anti-bacterial activity against various bacteria.
Concerns over transfer of contamination from wood to food get lessened when they make these observations:
“As wood is a porous material with a very complex distribution of porosity [88], the recovery of total microbial content is difficult [86,89]. Even the transfer of microbes from the wooden contact surface to food is lower as compared to other surfaces [73]; for example, [10] reported that the transfer rates of Listeria monocytogenes from wood (0.55%) to cheese was lower than perforated plastics (1.09%) and glass (3%).”
Considering cross-contamination is a danger that sickens people every year, this statistic is important.
Dean O Cliver, in his 1993 paper, said the following, which may have fed the commonly-accepted notion that wood is a harbourer of pathogens rather than anti-bacterial:
“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 used wood surface.”
Another paper published in January 2005 decided to eliminate the porous nature of wood, and use sawdust to see if various woods would still be anti-bacterial. They said:
“The presented study shows that pine and oak exhibit substantially better hygienic performance than plastic and indicates an antibacterial effect caused by a combination of the hygroscopic properties of wood and the effect of wood extractives.”
“…wood is well-known as a porous material that can absorb and retain bacteria, and thus it is regarded as impossible to be kept completely clean and decontaminated.”
“… in general, significantly fewer viable bacteria could be recovered from the wooden surfaces compared to plastic regardless of the wood species and the type of the inoculated strain (Ak et al. 1994a,b). Gehrig et al. (2000) found no differences in bacterial survival rates on boards of maple and beech. The study by Koch et al. (2002) revealed that oak showed the best result in elimination of Pseudomonas fluorescens and Bacillus subtilis on the surface of boards compared to beech and ash. Again, the survival rates of bacteria on plastic and stainless steel were always higher than on wooden boards.”
The study authors tested bacteria viability via PCR and DNA testing. Via these means, they discovered that the porous nature of wood to draw bacteria into itself and starve it via lack of oxygen or drying out wasn’t the only way bacteria could die, but by merely coming into contact with the wood. They say:
“These results indicate that the decrease in bacterial numbers on wood was not due to the ability of the test bacteria to enter the VBNC state or due to the transfer of the bacteria into the wood and close adsorption of the bacteria to the wood structure as argued by several authors (Kampelmacher et al. 1971; Ruosch 1981; Abrishami et al. 1994; Rodel et al. 1994; Lorentzen et al. 2000). Rather, the applied bacteria were killed completely due to interaction with wood.”
“The porous structure and hygroscopic characteristic of wood leads to desiccation of bacteria. Most bacteria are desiccation-sensitive and require a water potential of y2.8 MPa or less for growth in wood. This is significantly above the moisture content of air-dried wood stored indoors, so that properly dried wood does not offer bacteria enough water for growth and multiplication (Bavendamm 1974; Schmidt 1994). However, the present study revealed that desiccation of wooden material cannot be the only reason for the effects observed. During the experiments, all woods and plastic dried rapidly within 24 h, but on pine and oak a much higher reduction of culturable bacteria as well as a faster decrease of bacterial DNA on pine became apparent.”
“In addition, polyphenolic substances present in wood (e.g., tannins or flavonoids) could be responsible for an antibacterial effect (Field et al. 1989; Scalbert 1991; Field and Lettinga 1992; Cowan 1999; Rauha et al. 2000).”
This study wrapped up with the following statement:
“Some wood species like pine and oak showed excellent antibacterial characteristics, efficiently killed applied bacteria, and had clear hygienic advantages compared to other woods and plastics.”
The tannins and phenolic compounds found in woods such as oak, pine, maple, cherry, and others, are what make them anti-bacterial and safe to use in your kitchen. While the 1993 study didn’t see much of a difference in bacterial death between finished and unfinished woods, the finish chosen for the study was a mineral oil. As mentioned earlier, a researcher recently decided to test wood finishes to see what would happen to bacterial death. This study was published in March 2023.
They begin their paper saying:
“A growing body of the literature points to the hygroscopicity of wood—its ability to draw water and bacteria from its surface, deep into the wood, where the bacteria are trapped and die—as the wood attempts to even out its moisture content.”
“The coated woods had significantly more recoverable bacteria on their surface than did the uncoated samples. There was no significant difference in performance between the oils. Remaining bacterial loads did vary significantly by wood species, with European beech having significantly less surface bacteria when inoculated with Salmonella, and the oak species having significantly less surface bacteria with Listeria.”
“Samples with five coats of either linseed or mineral oil were not able to absorb the bacterial solution, which merely ran off the sample. As such, these samples were removed from the analysis.”
So if you like to be the one doing all the bacterial removal, coat your wooden cutting board in 5 coats of linseed or mineral oil, and be sure to maintain those levels as your knives cut through them. Otherwise, the researcher dropped to just one coat of each to continue with their testing.
“For both bacteria, the highest levels of recovery (~100% of inoculum) were, for wood samples, treated with 1 coating of linseed oil with variability between individual samples regardless of wood species. Similarly, wood samples treated with 1 coating of mineral oil also resulted in high rates of recovery of bacteria from all wood species. These findings suggest that one coating of may slow the absorption of bacteria into the wood grain, keeping the bacteria available on the surface of the wood.”
Interestingly, this researcher called out many of the studies done in the past, as using an extreme worst-case level of bacterial inundation of the wood (innoculum they call it in science circles), and the methods required to read the results, often giving numbers falsely enhanced by invasive techniques that would otherwise have left the bacteria where it can’t do any harm, assuming it’s still alive. So they add:
“Methods used in the study were intended to mimic pathogen levels (Listeria and Salmonella) that may transfer from contaminated food onto cutting boards with normal use (100 cells). Using this low level of inoculation, we could effectively sample and directly enumerate viable cells only from the top food contact surface of the wood without confounding results due to the recovery of bacteria that may have been adsorbed more deeply in the wood tissue.”
” Of the wood cutting board specific research to date, there was no significant difference found between tested wood species (1,2,3,4,7). Ak et al. [1,7] evaluated the survival of Escherichia coli on commercial wood cutting boards made from ash, basswood, beech, birch, butternut, cherry, hard maple (sugar maple), oak, and American black walnut. Within 3 min of inoculation, the recovery of E. coli was reduced to between 1 and 20% of the initial inoculum level (3–4 log CFU/sample) with no significant differences between wood species (7). In a second study, Ak et al. [1] also demonstrated a rapid loss of recovery from wooden cutting boards inoculated at >7 log CFU/sample with no difference between these same wood species. Schonwalder et al. [9] tested the penetration and survival of E. coli and Enterococcus faecium on wood boards and blocks of Scots pine, Norway spruce, European larch, beech, and black poplar using destructive sampling methods (sawing and grinding) with the collective results of various experiments pointing to pine wood having the lowest microbial recovery.”
This researcher is not very impressed with the modern way in which people will play a game of telephone to parrot “common understandings” that in reality, may be common “misunderstandings” or worse, misinformation.
“Scientific studies aside, the results presented herein are in direct contrast to popular/internet knowledge. Frequent claims are made on nonscientific platforms about how wood that is less porous (likely meaning diffuse porous, or ‘closed grain’) is ‘safer’ than wood that is more porous (likely meaning ring porous) ([10,11,12] among many others). Many sites discuss maples, walnuts, and cherries as being ideal, with woods such as oak, especially red oak, not being ‘safe’. These statements are based on a misunderstanding of anatomy and physical properties of wood and do not recognize the hygroscopicity of all wood. This study used two diffuse porous woods (sugar maple and European beech) and two ring porous woods (red oak and white oak), one of which had occluded vessels (white oak) and should, in theory, function more like a diffuse porous wood. Bacterial recovery from European beech wood was significantly lower compared to the other three wood species tested, although the oaks performed better with Listeria when left uncoated (in that they had less recoverable bacteria on their surface).”
An argument against finishing woods used in the kitchen is as follows:
“Our findings suggest that a minimal coating of wood with oil delays/prevents the absorption of bacteria into the wood grain and/or protects the bacteria from stresses associated with the wood surface (antimicrobial compounds, rapid desiccation due to hygroscopicity).”
So, pardon me for asking, but are we trying to protect the human, or the bacteria?!
This same researcher continues:
“Other studies, including Schonwalder et al. [9] and Chen et al. [5], found improved survival of Gram-positive bacteria on wood compared to Gram-negative bacteria. It is important to note that single bacterial strains were used in most studies, and so, care should be taken in overgeneralizing these findings. However, diverse studies on wood cutting boards consistently demonstrated that low levels of microbial recovery with a few minutes following inoculation and recovery consistently decreased as time increased (12–24 h post-inoculation) and did not seem to be impacted by humidity [1,7]. What is perhaps most interesting about this study is that wood species did matter: the species best able to decontaminate the wood surface for Salmonella was diffuse porous European beech, while the best species for Listeria removal was either of the oaks (ring porous woods). There was no ‘one best wood’.”
They wrap up with an observational warning:
“Broadly speaking, all coatings interfered with the wood’s ability to move bacteria, causing increased surface bacterial loads. The movement of bacteria was not uniform across the wood species tested, with some woods performing better with Listeria (both oaks) and others performing better with Salmonella (European beech). Coatings never improved (reduced) bacterial load, and often increased it. These results will hopefully serve as a springboard to testing commonly used wood cutting board finishes, particularly those that contain waxes and oil-wax emulsion, and may serve as an early warning to those that use wood cutting boards that the finish accessories commonly sold alongside boards may not only be unnecessary, but potentially harmful.”
While many woodworkers out there will tell you pine should not be in the kitchen, it does perform well when killing a wide range of bacteria. Oak is another that kills many of them as well.
If you are having to use the same board in quick succession across various foods, you want to be washing with hot, soapy water and rinsing with vinegar, because while a fair bit of the bacteria do indeed die in the first few minutes after use, the bulk are found dead within 24 to 48 hours. That time frame is not workable in a busy kitchen setting without multiple boards in use.
What’s scary however, is that the numbers of living bacteria found on the wood surface pale drastically in comparison to plastic or metal cutting boards. Plastic cutting boards have been tested by some of the above papers shared here, and by others not shared here, to harbour far more living bacteria than unfinished end-grain wood cutting boards!
So if food safety is your highest priority, make wood your choice for preparing your food. Keeping multiple boards for multiple tasks is a good idea, and if you can’t afford to wait even 5 minutes between tasks, having multiples for the same purposes too.
Various bacteria are most easily and quickly killed by various woods, so if you know a given board will be used most often for a given food that tends to harbour a certain bacteria, get a cutting board made of the wood that kills that strain the quickest, then label it. The studies shared here, note which woods in their tests, killed off the most common food-borne bacteria the fastest. And perhaps as noted by one lady’s article I chanced across, instead of mineral oil or linseed oil, season your board with olive oil. You’ll get the anti-bacterial qualities of both the wood and the olive oil!
To help in your decision-making, I’ve put together a sample chart from the information the studies in this article offered. You can use this chart to locate the bacteria you are wanting to kill, then note the wood, or conversely, find the wood you use or want to use, and note the bacteria it has been found to kill. Where possible, I’ve noted woods as Poor, Good, Better or Best, however, that info is scanty and only noted for a few of the more prevalent pathogens typically found in the kitchen that these papers tested for.
If you have found a study claiming information not present in the chart, by all means send me the study, sharing the quoted section where you got your information, and I’ll update this chart, and if the study contributes further to this discussion I may update this article with it as well.
Download the chart here:
