Here's a link to preservative-free juice concentrates. I believe they are also available on Amazon.We used to make a crude wine with some brand of bottled juice and then suddenly it quit working. I think they started putting a fermentation inhibitor in it. That was some 50 years ago so cant remember the brand. Is there a difference between the frozen concentrate and the bottled reconstituted product?
UnderstoodMaking a simple wine with those concentrates used to be a very simple operation. Not the most sophisticated wine perhaps, but I was not a very discerning consumer then either.
I have looked in on the process where you start with a case of grapes; believe me, it is a lot more involved, with more avenues for things to go bad.