PA goes funny if you open it after about a year, or three years if closed. Now that I'm repacking PA, I replace it every six months. 8 bucks a year is a decent investment.

The reason I use PA still, now that MP is available in my area has to do with the smiple fact that water that's pure doesn't help if you can't get it down. Tried it, and almost hurled.

When in doubt, BOIL. 100C destroys pretty much everything.

However, now that I double checked, I see that you are using a clear/colorless bottle, Coastie. Wrap a label around the bottle, becuase they do break down due to light. Amber bottles are much better if you can get them.