The only time I use sweetener is in my tea in the morning. I've opted for raw honey because it is supposed to contain properties, such as enzymes, which makes it at least somewhat nutritional. I use very small quantities (quarter teaspoon per cup of tea at most).

I ran out of honey, and had stevia on hand, so gave it a try. WOW! Way too sweet! I had to really watch how much I put in my tea. But, I don't feel it had an after taste. Maybe it is the brand you are using.