Bottle of Cachaça 51 tasting like sour milk? Whilst recently shopping, I grabbed a bottle of Cachaça 51 intended to use for some flambé. Upon opening it, I found it smelling (and tasting) like slightly sour milk.

Googling for it, I didn't come up with any hits about it at all, which makes me wonder what's going on.

Edit: I have had a straight Cachaça before, but it was a different brand, and it didn't have this sour milk taste.
Further research on this revealed my own answer: Bagasse is the waste product from extracting juice of sugar cane, and if naturally fermented/decaying, smells like sour milk!

Depending on the grade of sugar cane juice (freshness of sugar cane itself, as well as heads vs tails of extraction), the juice can have some of the bad flavour from the bagasse, and it's sufficiently volatile to persist in the distillation process!