NF phoned me and connected me to their chief chemist and then after that the CEO of the company spoke to me for a very long time.
In a nutshell, the residue was caused by me pouring the flavoring into an el-cheapo plastic cup. He said it wouldnt happen if it was a really good plastic, but that it will happen to the super cheap plastics like my cup was made with. He said it also happens to people who use a cheap plastic blender to make fruit drinks with their flavors, it etches a white coating into the plastic and if left long enough will crack the plastic. It is why they use only glass for their flavorings, never plastic.
Then I spoke to the CEO of the company. He asked me why I wanted to evaporate the alcohol out of the flavoring and then asked "are you using it for vaping". I told him yes but that I know his company doesnt want their flavorings used for vaping. What he said next was a surprise .. he said that they are the #1 supplier of flavorings to the ecig community, that most of the companies who make eliquids buy their flavorings and that, in about 3 days, NF is launching their own website which will be selling their flavorings specifically for the ecig community .. the website will be NewportFlavors.com and it will be open in about 3 days.
He then asked me how I make my DIY liquid and said, for the healthiest vape for my lungs I should only use 100% natural flavorings instead of putting other flavorings into my lungs that are made from synthetics.
As a child his grandfather smoked pipes .. and he grew up watching and smelling his grandfather cleaning his pipes every night. It is what got him interested in flavorings at the young age of 4. To this day he can remember the smell of each of his grandfather's pipe tobaccos. The ecig flavoring website that he is launching in 3 days will have all the fruit and sweet and bakery flavorings but will also have pipe and cigar flavorings.