Plain TFA Peppermint is a very old ADV of mine and I vape it at 6% (Used to be 10).@ChelsB - Could any of the meds you're taking lately be affecting your sense of taste? I know some can/do for other people.
By the way, is that Peppermint TFA? If it is...I don't see how you can do 7% and vape it. It would give me a massive headache. I've used just 3-4 drops in a 30mL mix and that's strong enough for me and a guy I make it for regularly who used to smoke menthols for 40+ years.