Amazing progress fermenting with bananas

[Pendragon524]

Today I discovered that bananas apparently have some magical ability to make yeast ferment extraordinarily well. A few weeks ago I posted here describing my issues trying to make wine out of Oceanspray cran-raspberry juice. The fermentation stalled out around 9% ABV, despite my using a 15% ABV-tolerating yeast, and the wine was way too sweet to enjoy drinking. Upon someone's advice, I redid the fermentation with a pound of mashed bananas added to the must (and using a 13% ABV-tolerating yeast). Two weeks later (today), I took a gravity reading and lo and behold, it indicated that my must was now at 13%, and almost dry.

So my question is, does anyone have any scientific explanation as to HOW bananas accomplish this magical feat of encouraging fermentation? Do they have the right chemicals to act as yeast nutrients? Any information would be awesome.

 

[Hoppy2bmerry]

My best guess would be they provide nutrients.

 

[pdxal]

Per above, nutrients.
Other possibility is buffering the acidity in the juice.

 

[Yooper]

Both of those. Also, interestingly, bananas are used as body building agents in some wines, particularly thin wines like dandelion or blueberry.

Bananas have simple sugars and ferment very well.

 

[Seamonkey84]

All the above plus the added potassium helps the yeast deal with the alcohol better.