using cooking propane torch held sideways I have acquired a Benzomatic torch to attach to a propane tank to use as a cooking torch. There is a warning that the tank must be kept upright during its use. The explanation is that if tilted the liquid below the gas contributes to the flame making it extra hot and adds non-combusted hydrocarbons to the food which can be tasted and may be unhealthy. Can anyone give me some guidance? It is extremely difficult to try to use the torch in an upright position for cooking.
Practically speaking, you can tilt the torch down about 60degrees.  Beyond that, it will tend to either cut off or flare.  However, tilting it down that far is good enough for most purposes.  Wanting a better angle is one of the reasons why more expensive "kitchen torches" exist.

So, if tilting some isn't good enough for you, you can buy a kitchen torch, a gun-shaped propane torch (which isn't less expensive, but is more powerful), a gun-shaped butane torch, or even a propane torch with a hose attachment.