Exactly as it says on the can. 100% Grade A question, no byproducts.
You need cooking 5 and you’ll autolearn the recipe for juvenile sourdough starter, which turns into normal sourdough starter after a week. You need some water, some flour, and I think either a glass jar or a glass flask.
Technically you get the yeasts and bacteria from the air.
Seems like it should spawn in grocery stores and bakeries, too, but it doesn’t.
That probably wouldn’t be active liquid starter, rather the powdered kind that you need to mix and reactivate. When I added starter I didn’t do that kind, mostly because I was speeding native starter up to the point that it’s almost as fast as using a powdered starter anyway.
Oh, I didn’t realize the starter was a liquid in-game. It didn’t leave an empty container when I would use it, instead vanishing entirely like a powder. Which is actually weird now I think about it.
It shouldn’t behave like a liquid nor a solid, it behaves like a jar of goop. When you use the starter you should get an empty jar back.