Hello,
Preparing for a tasting of modern Beaujolais, we opened two bottles of
the lower rungs, one of which was a Faiveley B-V 2009. This was a
pleasant enough wine with a good structure and clean acidity, but, on
the nose, a great deal of marshmallows/ripe banana - not like a Bojol
Noveau, but still, quite noticeable. We did not finish the bottle, but
after 4-5 days drank what was left and, the marshmallows had
disappeared, leaving undergrowth, possibly a hint of violets, and
blackberries.
According to at least three different sources, the marshmallow/banana
smell derives from an industrial yeast and is caused by isoamyl
acetate. So, not really caused by carb mac, then.
I would like to know what the carbonic maceration does to the
organoleptic qualities of wine, apart from lowering acidity (which
appears to be a given, and needful with Gamay which tend to produce
high acidity).