BAD GAS !

471.........471 Whoa!
Number one question; is it oxygenated?
Number 2 what color is it?

-Clear is fresh and ready to explode
-Yellow is refreshable at 50%, but stay out of the secondaries.
-Orange is no-good for carbies, but can be burned in your EFI car.
-Red is totally skunked, feed it to your neighbors Taurus. Bulls drink anything.

Here's another test;
Pour a teaspoon of it onto a cement floor. Light a piece of paper on fire and drop it into the puddle. If it smokes, it is going bad. If the flame jumps up and down, like it can't get air, and it smokes; it is no good for carbies, not even your neighbors lawnmower. If it leaves behind an oily stain, it is long past it's Best-before date, but is still good for starting bushfires.
I say cement floor cuz that's how I have always done it. I have done it on a steel plate; but that usually leaves behind a really greasy stain.I think the grease comes up out of the steel. The cement floor needs to be a typically smoothed surface, or the lighter gas disappears down into it, and you can prove fresh gas-skunky. I have not tried it on a hard glass surface, although I suppose I should have.