I want to use the teak wood bowls I bought at a frontier sale as soup bowls. Wood bowls are one of the types of excepted utensils for juried frontier reenactments.
Wood and water don't mix. I would not use it for soup. I use my wood bowl for chopping foods, especially meat. I wash it with soapy water and condition it and my wood cutting board with food-grade mineral oil.
If wooden bowls have been cleaned and seasoned properly then you should be able to serve any type of food.
The biggest danger to wooden bowls is leaving any type of liquid in them for very long. This may be a problem with soup - unless the soup is served, finished and bowls cleaned in a short period of time.
Here is a site that gives a lot of information about how to clean and care for wooden bowls:
I'm not sure that it could ever be a good idea to eat liquids like soup out of a wooden bowl, especially if they have been treated. But things like salad would probably be ok
Dip a clean cloth in 3-percent strength hydrogen peroxide and coat the wooden bowl. ...
Fill a sink with warm water and dishwashing detergent. ...