Felt food is surprisingly durable. Wool and wool blend felt is meant for heavy duty use. That being said, you do have to be careful about rapid temperature change and heat or scrubbing it. Heat makes wool shrink. Scrubbing will make it pill.
So if your felt food gets messy beyond what can be brushed off (say for instance a cup of juice gets spilled on it or your toddler is potty training and it's not going so well) follow these steps.
1. BEFORE you get it wet, brush as much of the dirt, dust or dried whatever off as you can.
2. Fill a sink or bowl with 2 parts cool or cold water and 1 part vinegar.
3. Place said item in water and wait until it soaked, gently squeeze the air out if it is a stuffed item.
4. Gently press water out of felt without rubbing
5. Continue to squeeze like a sponge do not rub, Repeat until spot is gone, you may soak the felt overnight if needed.
6. Air dry, felt may feel stiff at first but will regain its softness when played with for awhile. DO NOT put your felt food in the dryer. It will be done for!