The bit about the cutting boards being as hard as stone, is that pure hyperbole or is it possible?
The bit about the cutting boards being as hard as stone, is that pure hyperbole or is it possible?
I've broken more than one high quality steel bit on various kinds of wood, but that's usually not a measure of how hard the wood is but how much friction there is between the drill and the wood and how much of the drill bit is inside the wood. If the wood were really hard you would not be able to enter the bit at all and it would never break but just sit there spinning on the surface.
Finally, the whole trick to a cutting board is that end grain wood will wear very little and the knife will be sharp much longer specifically because it is not as hard as stone.
Here are some videos for the readers:
https://www.youtube.com/watch?v=oTNVDH6ZFLg
https://www.youtube.com/watch?v=isFTIHy7Duo
You will see pork bone chopping (beginning of the video), skin slicing (1:40), and meat grinding (5:30) in the second video.
Those are very typical boards in a restaurant's kitchen. The typical household chop board is a lot smaller and thinner, probably around 35" wide x 5" high. However, many families have moved away from wooden chopping board because plastic boards are easier to clean.
As far as resistance to bacteria, that will fall short with science. The passing down from generation to generation is a cultural effect. If you live with your in-laws, the board will of course be reused. Since wooden boards don't crack for years, yes, the board will be passed down. Butchers (Chinese and other cultures) use wooden boards because of the durability (Chinese chefs love chopping real fast with force). Real chefs prefer wooden chopping board (yeah, your famous Gordon Ramsay!)
Also, it is very common to see a butcher or a chef to stick the big kitchen knife on the side of the board tilted like the Leaning Tower of Pisa :-) The strength of a real butcher or a real chef can be so much more powerful than a MMA boxer.
EDIT: If you want a short English intro on this topic, https://www.youtube.com/watch?v=gDdoht0e1sg is solid.
There's a foil edge on very sharp knives that will wrinkle and fold after use on anything, even tomatoes, making the knife feel dull. It's not, and it doesn't require removing metal as with grinding or sharpening, but you can steel to realign that edge or strop to hone it depending on the blade and angle. Even if you don't work with blades often, you've probably seen this depicted in media.
It really doesn't matter what the cutting surface is to the knife if you have great technique. Since I don't always, I use thin, flexible plastic barriers. I would never recommend wood outside of having no other choices or using it as part of presentation, mainly because of cross contamination and difficulty in sanitizing if you cook sous vide or serve raw often.