Hi KjAthena!
First off welcome to the world of DIY E-juices!

I would not recommend using McCormick's Pure Peppermint because its pure oil, and I tried that once when I first started DIY juices and it gave me a weird coating on my throat and made me feel sick for a while. The peppermint flavorings you can buy that are "Okayed" for e-juices do contain peppermint oil but lower amounts, thus not having any adverse affects. Plus, you will really need sweetner for your e-
juice batches or anything you may make will taste terrible! I would recommend waiting and buying the proper flavorings and sweetner to mix with your nic 12mg pg....And Yes, Pure Peppermint oil runs the risk of a tank cracker...So I wouldn't risk it! If you're really wanting to try something NOW!!(Excited

) Then try a little Vanilla extract with your nic pg and some diluted Splenda in distilled water in mix together....I've tried this and it does work...not all that great I may add, but it will be vape~able.

Have fun!