I dunno - I've made quite delicious banana wine using only banana peel. And there is a scholarly journal article by Syriac et al (2017) discussing wine making in India that talks about using peel for this wine - and before you snort - limoncello uses only the zest of lemons to make that liqueur and my own preference for orange wine avoids the juice and uses only the zest... Oh... and if you want to make a wine using the flesh of bananas you really need to make sure that the bananas you use are really ripe. Yellow is far from ripe. Blackened bananas are ripe. And - the beauty about using banana peel to make this wine is that for most folk the peel is 100% waste so the cost (apart from the added sugar) is zero... and you are upcycling a waste product to make it something quite delicious and desirable...
(for the record, each time I eat a banana I collect the peel and store it in my freezer).
Sadly, the article does not state how much peel was used (for a gallon, I might suggest 12-15 peels) but it does suggest that they boiled the peel for 25 minutes after which I presume they strained the peel. The authors then added sugars to bring the concentration of the sugar in the liquid to a Brix of 29 (or a gravity of 1.124) - or a potential ABV of about 16%. Me? for drinking purposes rather than to see which kind of sugar source is preferred, I would aim for a starting gravity closer to 1.090. The paper does not specify the yeast they used. I would look for 71B or D47 or even Premier Blanc. And I would add nutrients. Banana peel has a great deal of tannin but as bananas ripen the tannin I think is converted into sugars. I wouldn't add any acidity until the wine was ready to bottle and I would aim for a TA of about 6g/L. The authors measured the pH and that was around 4 - 4.4 on the 41st day of their project and 3.8 by the 71st day. The TA they measured was 7.7g/L on the 41st day and had risen to 9.1g/L by day 71... so that is a quite tart if as they indicate their samples were all brut dry.
Journal of Pharmacognosy and Phytochemistry 2017; 6(4): 591-595
I just started a banana cranberry wine today. Reading on this forum, I have been inspired to try a second run from the batch of Christmas cranberry wine I have in primary right now: Christmas wine recipe. I will use the pulp bag and some of the lees from that to start the banana cranberry wine. I also have an extra 1 lb. of cranberries to throw in.
I think that using both the bananas and peels would work well.
Since I posted here earlier, I thought I'd show you what my Banana Cranberry wine looks like now after 3 days in the secondary. It is remarkably clear for so little time in the secondary. This time I simmered my bananas and then just poured it into the primary instead of putting it in a pulp bag like a normally do. Because of that, there were a lot of banana parts in the primary. I thought it would clog up my racking cane. So I poured the must into a sanitized bucket through a fine mesh bag. That strained out all of the banana parts.
If this turns out well, I might consider straining in the future. To help deal with unwanted oxygen, I sanitized the bucket and mesh bag with Kmeta, so that there would be some residual SO2. Hopefully that will help.