I was at Bed Bath & Beyond and I spoke to one of the employees about knives with wood handles. She said that wood handles are no good because they warped from water and heat and were difficult to sanitize (especially if you're . But what about knives such as the Wusthof Ikon knives with blackwood? I find it hard to believe such an expensive knife could have those flaws, especially if one is properly cleaning, drying, and storing them properly. (My question isn't speficially about the Wusthoff knife, but about knives with wooden handles in general).
Knives are very hard-worked tools in the kitchen, and need to be easy to clean and maintain.
At all quality levels, unless resin impregnated or otherwise treated, wood does not stand up well to harsh treatment, such as frequent trips through the dishwasher. Even if washed by hand, you want to wash it and then dry it, so the water doesn't soak in and lead over time to cracking and warping, plus a rough, unpleasant feel in the hand as the fibers expand and separate.
As to sanitation, wooden handles are much akin to cutting boards. If treated properly, it is not an issue. You can even, occassionaly, use a mild bleach solution (followed by rinsing and drying) to sanitize them.
If treated with reasonable care, by handwashing and immediate drying, wooden handles will perform very well, and of course they are very attractive.
Still, on balance, wooden handles require more care than some of the resin, plastic, or metal handles. Choosing among the options is about balancing the feel and beauty and maintenance to your needs and desires. For me, personally, I choose the resin handles as they are very durable and low maintenance.
Wood has natural antibacterial properties where as plastic and resin provide a hospitable environment for bacterial growth. For that reason, you might want to consider using wood handled knives and cutting boards.
The high heat and steam and dry cycle is really unfriendly to them.
Some the resin handled Wusthofs in our kitchen have cracks in the handle because they've gone for joyrides in the DW.
On the other hand, we have wooden handled knives (Victorinox) that aside from fading a bit, look great and are well over 10 years old. I also gave a set as gifts to someone who does send them through the DW from time to time, and theirs are a little worse for wear but still ok a decade later.
You can place plastic handled knives in the dishwasher, but the blades tend to dull out faster (I haven't figured out why, and don't care for putting knives in the DW).
Here's some advice/quote from a friend who quit her modelling career to become a well respected chef: