Where does saliva come from? Yes, I know it comes from the salivary glands but how does it get there?

It can't come from the lymphatic system as it's drainage/refuse. Nor the blood system for that just doesn't make sense and the blood seems too valuable.... So, does it come from the stomach? Well then it should taste of hydrochloric acid and it doesn't, it tastes of alkaline. So where's it come from?