There are two ways it can do this – you can either pump it into another tank or barrel to let it chill out for a bit before you bottle it. Or you can leave it in the vessel where it underwent its alcoholic fermentation.
This second method is what we call resting the wine on its lees. And lees is just a nice way of saying dead yeast cells (how appetising!).
After a while these yeast cells start to breakdown (the technical name for this process is yeast autolysis, in case you’re wondering) and guess what kind of flavours this imparts on a wine? Exactly those yeasty and bready would expect, it can smell quite like the starter or ‘mother’ of sourdough.
This process also helps to add body and texture to a wine.
Wines like Muscadet will often undergo this process, and this will be indicated by the term ‘sur lie’ on the label. Chardonnay’s can undergo this process too, but the label might not necessarily allude to this.
Lees aging is also a key part of the Champagne making process, but here it occurs for a much longer period – a minimum of 15 months, hence why Champagnes have those intense toasty, biscuit, bready or brioche flavours that people often experience when tasting them.
You can even give the wine a little bit of a helping hand and stir the yeast cells around a bit, a process which winemakers call ‘Battonage’ which gives an even greater yeasty flavour to the wine.