Making cutting boards has got to be one of the most popular woodworking tasks. I can't imagine how many cutting board videos have been uploaded to YouTube and others all of the information that abounds ...
Watch it on Youtube: https://youtu.be/ObleuPPO3mM
This article and video are based on my 20 years of reading articles and publications from researchers who test cutting boards to evaluate their safety and report on their findings.
In most of the articles I have read, researchers pay little attention to the type of wood being used. What they are typically looking at is what is the health of the board in terms of pathogens. What bacteria are present and in what quantities, what other things are present, and what is the cross-contamination if any.
As woodworkers we obsess with types of wood to use and why, what food-safe coatings should be used, and what types of glues are best.
Somewhere in the middle of these is the basis of a "best practices" guideline that would be helpful to new woodworkers.
Tip #1 What Woods to Use
Many research papers don't even touch on the types of wood. The only time this comes up is when they are comparing something like plastic to wood. Rarely do they ever compare woods? The biggest place for pathogens to congregate is in cracks on cutting boards. These cracks can be loose or unfilled glue joints or they could be knife cuts. What researchers want to know is what bacteria are living in these cracks and what quantities.
As woodworkers we often hear that softwoods are should be avoided because they wear out quicker and can leave bits of wood in the food. Wearing out quicker is actually a good thing because many findings indicate that cutting boards should be replaced more often than they are and bacteria in the cracks and holes are continuing to grow and multiply. As for the bits of wood in food ... anyone ate popcorn, walnuts, almonds, or peanuts?
Another thing I hear from time to time is that we shouldn't use Oak because it is "open pore" ... but that doesn't account for all the white oak barrels that are used to age wine, whiskey, pickles, peppers, and other food stuffs. The fact is, Oak has a high content of tannic acid which is a natural antibacterial agent. So Oak is actually one of the BEST woods to use.
On the whole, pretty much any wood I can think of that grows naturally in the northern hemispheres would be suitable for a cutting board with the possible exception of Cedars, especially Western Red Cedar which is high in oils. By itself, it is an excellent cutting board, but when glued together cedars often fail over time which creates cracks in the wood where bacteria congregate. A single wide cedar board would be fine, but glued may be problematic. Similarly with oily exotic woods which also do not glue together well. Yes, we can use Acetone on them to get the oils out, then glue them, but the oils in woods always migrate to the surfaces and when this happens the glue begins to fail and leaves cracks for bacteria to enter.
Tip #2 Use the Fewest Glue Joint Possible
This really just a common-sense issue at this point. We know that cutting board risks are primarily from pathogens that can live in cuts and cracks so we need to try and avoid these and the best way is to limit the number of joints.
This tip also includes the much loved, but much riskier "end-grain" cutting boards which are beautiful to look at and wonderful to use, but much riskier in terms of the number of glue joints and the fact that the end grain soaks up liquids. I have long said that end grain cutting boards should never be used as cutting boards they are Kitchen Art and should be used as such. Sometimes these cutting boards come in contact with larger amounts of water on the counter which makes the wood swell and presto, now we have a large crack-in and end grain cutting board. These cracks will come back together when the wood dries but now that cutting board is compromised and should never be used again because there is no safe way of filling in those cracks that opened than closed. They are still a point of entry and contamination for pathogens and just not work the risk to use.
Tip #3 Make Sure You Glue Squeezes Out at Every Joint
When this happens we avoid "glue voids" or "voids" in the wood from lack of glue. If you have these they are nearly impossible to fix and when you try to fix them it is always uncertain if you have been successful of not. The best way to avoid doing this is to have squeeze-out glue at every joint.
Tip #4 Never Use any Wood with Knots, Cracks, Voids, or other Defects
As noted above, do not give bacteria and pathogens a place to congregate and multiply. Some people will say you can use CA glue, but these are brittle glues and at some point, you will crack the glue which again opens the risk of bacterial gatherings. Other options like Epoxy coating and glues may possibly be an option but starting off with quality wood will save TONS of time later on in trying to fix mistakes and other problems.
Tip #5 Use Food Safe Coatings
I have little to say here except that these coatings are primarily used to enhance the "look" of the cutting board and I struggle to know what other possible benefit they might hold ... depending on the coating. Most coatings will be wiped away completely in the first couple of weeks of use. Cutting boards should be washed with warm soapy water, then rinsed, wiped off than allowed to dry completely after each use. The "drying completely" stage is one of the best things that can be done to reduce and limit the number of bacterial growth.
If you follow these tips you will be well on your way to making healthy and safe cutting boards for you and your family and for those you may be selling these items to. Change your cutting boards with some frequency and any time you see straight black lines on your cutting board, you can be assured that a glue joint is failing and that bacterial have filled and thriving in that crack. The best cutting boards have NO glue joints and are constructed from wood that contains natural anti-bacterial resins.
The photo below is actually a glue line between 2 boards that were dyed black so you can see it. I did this for 2 reasons.
1) to illustrate what an actual failing glue joint looks like on an existing cutting board. It often looks like a black, blurry line when in fact it is an open glue joint that has filled with bacteria and other nasty pathogens. If you have black lines like this on a cutting board, it's time to discard it and get yourself a new cutting board.
2) the other reason I made this was to show just how wide the glue line joint is between 2 boards. The actual thickness of this line is actually less than what you can draw with a pencil and I made this to show just how much actual glue there is on a cutting board that "might" touch the food you are cutting. We are told to use "food safe" glue but I have serious doubts that the tiny amount of glue that 'might" touch my food, actually has an immeasurable difference on the taste, quality or safety of any food.
Copyright Colin Knecht