Why are there toasty/bready/yeasty/cheesy flavours in my wine? Is that a beer flavour?!
It’s one of the first aromas I notice when drinking Champagne or other traditional method sparklers. That immediate toasty/bready/yeasty smell.
The jargon name for it is autolysis and it occurs in still wines as well. The reason is because during winemaking the lees (the deposit of dead yeasts) are left in the wine. This is called lees fermentation (though technically not a fermentation at all).
It has a few impacts. Noticeably, it gives the toasty or other autolytic flavours, but also combines with other processes such as oak maturation to change that flavour as well.
It affects mouthfeel too. The creamy texture that you find in some premium white wines, is derived from lees fermentation as well.