As soon as the map loads for the first time, if I recall correctly. Also, from what I've experienced, it seems to depend on your character's aptitude/skills. For instance, if your character has a degree in, let's say, Smithy and Explosives, you're more likely to find ingredients for items created through those tech colleges.
Also, please try to keep topic titles a bit more descriptive. "W00t" isn't quite what you should go for when asking for help.
