How long do i have to wait after a tooth extraction before i can safely chew in that area?

It varies.: It's best to avoid chewing things that break up into sharp, hard pieces until the hole completely closes. Other than that, i would stay away from chewing in the area at least until the stitches, if any, are removed. Another way to judge- if it hurts to chew there, don't do it!

Until it heals: This will vary among individuals and will depend on the complexity of the extraction, so an exact time cannot be given. Use some common sense and avoid the area until it feels mostly pain free if you push your tongue against it.