After several years of beer brewing, I started experimenting with moonshine. I figured since Im distilling I dont have to deal with all the exacting procedures of beer making and I just needed basic sugar water to ferment and distill. So I did just that. I added 2 packages of white table sugar (https://i.pinimg.com/236x/c5/a9/e0/c5a9e0778a611c8f8da53f1ec038ed2c.jpg) and 4 gallons of fruit juice to a bucket of water mixed it and added yeast. I sed this high ABV distillers dry yeast (https://www.amazon.com/gp/product/B0064O77LQ). The first time I did this the yeast went CRAZY! I had heavy foam coming out of the airlock! Ive never seen that before. The resulting 'beer' was fairly disgusting, but after distilling 2x made some great shine.
Fast forward to the 2nd time I did this, 4 months after the first time. I added the same yeast (which was sitting in an unrefrigerated ziplock bag) to the same wort. Hydrometer said it was supposed to be 15% ABV. This time however, the fermentation is going super slow, and pretty much stopped at 7.5%. The max rate of bubbles in airloc was 1 every 3 seconds - pretty slow even for beer. Thinking the yeast might've went bad, I added another yeast (https://www.amazon.com/gp/product/B0064O6Z4Q/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1). Still nothing. Its still fermenting but super slowly. Last check the hydrometer was at 5% ABV. This is after 2.5 weeks.
Whats going on?
Question 1: Can yeast process water + table sugar or does it need additional nutrients (ie like https://beerandbrewing.com/what-exactly-is-yeast-nutrient/). Does fruit juice help? If so, why did the fermentation work so well last time?
Question 2: What can I add to save the batch?