Nicotine, also referred to as freebase nicotine or nicotine liquid is directly extracted from tobacco. In this process, all the impurities found in tobacco are stripped away. Leaving you with nicotine in its pure form. This form of nicotine is used in almost all e-juices on the market today. Freebase nicotine has a high alkalinity with a PH level around 7-8. Why are you telling me this? Well, because the PH level directly correlates with the severity of harshness the vaper experiences during inhalation. The higher the nicotine strength, the harsher it becomes.