What is Mouse?

what is mouse in wine

Well one thing it’s not is a mouse in your glass for any beginners out there, generally referred to as mousiness, is a fault in the specific bottle of wine you might happen to be drinking. Very few people on this planet actually enjoy the taste or later setting in aroma of a moussey wine, although what especially needs to be considered is a great quote from winemaker in the Languedoc, Paul Old  - 

“To make great wine is to flirt with fault” 

Mousiness is a bacterial infection that can most likely happen when the wine has been exposed to some form of oxygen, possibly after the bottle or racking stage of the process. When the wine reverts back to an anaerobic environment, it settles and the taste disappears. You can’t actually get any smell from amousey wine, because it is not volatile at the pH of wine, but the smell will become much more apparent when you taste the wine itself. Mousiness generally leaves an aftertaste, quite reminiscent of off-milk or wet cardboard notes, that linger around your mouth. The general population tends to be mostly sensitive and against mousiness. 

Although people all across the wine industry believe that they have the root cause of mousiness in  wine figured out, scientifically it’s still undetermined where the fault truly occurs, here’s a quote from Dr.Paul Grbin of Adelaide University and Dr. Alison Soden of AWRI speaking on their recent studies around the so-called fault - 

It will be interesting to see which of the many proposed mousy compounds are actually causing the mousy characters, and if in fact it is the same compounds each time” 

It’s hard to put your finger on exactly where or how mousiness occurs whether that’s during the fermentation process in the cellar or during bottling in an environment that boasts poor hygiene. 

Frank Corneilisen the famous producer of the oh so juicy ‘Susucaru’ amongst other fantastic natural wines and lead influencer within the industry also has his opinion on the subject of mousiness which in his opinion boils down to cleanliness and impeccable hygiene inside the cellar. Frank is “ a maniac when it comes to hygiene” and is willing to invest in any type of natural solution so long as it helps him keep his cellar spotless, to help fight the battle Frank uses things like ozone, compressed air and anti-bacterial sprays almost anywhere he can. 

What is absolutely true about mousiness in wine is that it’s not what you want to be drinking no matter what the circumstances. If the glass you just bought at the bar tastes and then smells like wet cardboard, let them know and get it changed. The same goes for buying a bottle with whoever your online or physical retailer may be, if the bottle is instantly mousey as soon as you crack it open get it back to the shop and hopefully they’ll be happy to help you with a replacement bottle.