Care and Handling of Wooden Spoons and other Wooden Utensils
Cleaning Wooden Cooking Utensils
I don't recommend putting wooden spoons and kitchen utensils in a dishwasher. It will seldom destroy them immediately, but they certainly won't last as long. Just wash wooden utensils by hand using the same type of detergent you use for any dishes and then put them in the draining rack. However, don't let them soak in wash-water for hours as they are likely to end up looking dingy.
Mind the Metal!
Never leave wooden spoons or kitchen utensils in contact with iron when they are wet or they will get a black stain which will NOT come out! This includes tinned cans and baking pans as well as cast iron skillets and the like.
Refinishing "Fuzzy" Wooden Utensils
Wood is made of fibers. Cutting these fibers in the process of making something out of wood leaves many thousands of tiny cut ends. I think that when one sands the wood down smooth some of the fibers are broken off but many are just smashed down. At any rate, when you get smooth sanded wood wet, it tends to fuzz up or roughen on the surface. This is commonly called "raising the grain". If this happens to a wooden spoon the first time you get it wet, let it dry again and then rub the fuzz off the dry wood with fine sandpaper (320 grit works well), steel wool or a dry, fairly new Scotchbrite scrubbing pad.
Don't sand the wood surface down until you get to a new layer or the same thing will happen again; just do it enough to break off the fibers that are sticking out. It depends on the nature of the wood whether you will have to do this two or three times or if once will be enough. Some woods hardly need it at all, and if you ignore the roughness and just use it, the fiber ends will eventually wear off and be gone anyway.
How to Season and Treat Wooden Spoons
To refurbish an old, well used wooden spoon simply apply a small coat of olive oil and rub it in.
If you put oil on a wooden spoon, I have been recommending olive oil because it won't turn to a sticky scum on the wood the way that most kinds of vegetable oil will. Some people tell me coconut oil is even better, but I don't have personal experience to know for sure. Shallow spoons may be oiled or not. They will survive without it. Wooden ladles and deep wooden spoons should be oiled, and the oil will need to be renewed from time to time. The more they are used the more often they should be oiled. The purpose of oiling is to keep the end of the spoon's bowl, the most fragile part, from soaking up with water and so swelling and shrinking every time it gets wet and dry.
Some spoon makers use walnut oil or other oils that dry by oxidation. I do not, as I don't think that oxidized oil can be good for a person. Some people are drastically allergic to such oils, too. One customer was relieved to find untreated wooden spoons because her house-mate was made quite sick by food she cooked with a spoon treated with walnut oil.