The burnt taste is often from solids which have formed inside the atty. I think certain liquids have more tendency to do this than others. In any event, you need to clean the atty well to get rid of the solids. I soak mine in denture cleaner, then Everclear, then boil them. About 4 hours in each and a 15 minute boil. You can see the solids floating in the solution. Sometimes the atties come out of it vaping really weak and never come back, other times they are like new. But the burnt taste is always gone if I seek it long enough.