On the left is the pineapple vinegar I began last month by steeping pineapple skins in brown sugar.
On the right is the banana vinegar, made by letting overripe bananas rot and seep.
Both recipes came from Mexican cooking maven Diana Kennedy, both have been decanted and tasted.
Pineapple vinegar. This smells incredible, bright and tangy, like some bionic pineapple just exploded. (Not sure that simile works, but hyperbole is called for.) You open the jar of vinegar and the whole room is perfumed with one of the loveliest scents ever generated in my kitchen. The vinegar is also gorgeous, a cloudy gold nectar. The flavor is sharp, vinegary, very pleasant, if not complex. I would rate this a moderate success.
Banana vinegar. The aroma is so mild I can't really describe it. As you can see, the vinegar is inky, opaque, not all that appealing. I was reluctant to taste this; I shouldn't have been. It is delicious. This is a thicker, more syrupy vinegar than the pineapple; it also tastes more substantial, sweet and rich, distinctly sour but full of honey and caramel flavors, and, of course, banana. It's like balsamic, but maybe even better.
No one could be more shocked than I that this experiment actually worked. Thank-you, Diana Kennedy. Both vinegars need to sit for a while more, but given my exceedingly low expectations, I am exceedingly happy with the results.