As a general guide, fermented apple juice is alcoholic from when it begins to ferment. While alcoholic drinks are commonly formalized as those containing a higher degree of alcohol( between 1% and 40% of alcohol), the truth is anything that is fermented is more likely to contain either alcohol or traces of it. And apple juice in particular, will contain higher levels of alcohol good enough to get you drunk. This is because it has a sugar content that ranges from 5-12%. This is also true that if you ferment apple juice with yeast, its sugar content will increase and so will its alcoholic percentage. If left for about two weeks, your apple juice will contain at least 2% alcohol content.