Post #763396 by Swanky on Fri, May 6, 2016 5:57 AM

Maybe an overly simple point, but, if your syrup goes bad, it will happen on top. So before you pour that bottle, look closely at the surface of the liquid and the edges where it touches. That is where you'll see mold. Also possibly on the sides above the liquid.

This also requires clear containers.

If the sugar content is high enough and the alcohol around 70 proof, you should be good, but regardless, sometimes they go south.