First, check a few things:
1) Does your wine taste dry or bitter, or does it taste super sweet?
2) Are there any carbonation bubbles in your wine?
If your wine tastes dry, bitter, or carbonated, there's alcohol in it indeed! We know this because when yeast produce alcohol, they eat sugar (making your drink less sweet) and produce carbon dioxide. However, the less-than-ideal flavor is another problem we can fix. Check out the rest of this section for more tips.
If it tastes super sweet and flat, then you likely have only a little bit of alcohol in your wine. To troubleshoot, check one more thing — does your juice have potassium sorbate in it? (Very rare). It's an ingredient that prevents fermentation, and can be found in Bang Energy Drinks, some simple syrups, and some farm-fresh juices.
All good? Now that you've determined that it doesn't have much alcohol and doesn't have potassium sorbate, you're good to move onto the next steps.
Most of the time, a low ABV comes from yeast that weren't energized enough. So, in order to encourage our yeast to eat more sugar and produce more alcohol, we need to re-energize them. If you've racked your Brewsy once or less, you can do this.
Take your Brewsy outside of the fridge, if it's in there. The yeast have gone dormant in the cold, but they can be re-energized in the warmth. To give your yeast some more warmth, place your bottle in the sink. Run it under warm water, (about 85°F) and plug your drain. Let it sit in the warm water bath for about 20 minutes.
After that, insulate your Brewsy with a warm blanket or heating pad, and let it ferment for 5 more days. Being surrounded in warmth will give your yeast the energy they need to start converting sugar to alcohol! After those 5 days, taste-test it to see if it's dry enough for your liking. If it is, you can cold-crash it and rack it again, then enjoy!