Friday, 4 September 2015
A bit on Brett
"Brett" (or Brettanomyces) is a term banded around often in wine circles. I attended a judging a few months back, a lot of the wines were dismissed for their "faulty" brett-like character, with one fellow judge eventually admitting he had a soft spot for the little blighter.
I had a friend bring home some local, artisan, red from a recent trip to France. He said the wine had a certain note to it which he couldn't put his finger on, but knew that he liked. Brett.
So, Brett. What is it?
Brett is a yeast, more commonly noted down as a fault in wine. A spoilage yeast. A wine displaying a Brett character will smell like various things, depending on the consumer. The more common aroma profile is one of a sweaty band-aid, this is bought on by the release of 4-EP (4 ethyl phenol) by the yeast. Some people have a low tolerance to this compound and will easily pick up the smallest traces of Brett, others will happily drink a glass which is full of the little buggers without the slightest pick up of it.
Brettanomyces are found firstly in the vineyards, on the skins on the fruit selected for harvest. It is thought that they are carried into the winery during berry processing. Brett is not the yeast used for alcoholic fermentation. This yeast is Saccharomyces Cerevisiae. A plethora of yeast are present during the early stages of fermentation (kloekora, brett, sacch), but sacch are the most tolerant of the harsh conditions left at the end of alcoholic fermentation (high ethanol, low pH), and are highly likely to be the only survivor at this stage, a bit like Hulk Hogan at a Royal Rumble (although to my knowledge, Saccharomyces are not racist bigoted old men).
Still using the Wrestling analogy... Brett (the hitman-Hart, obviously) tumbles into the ring at the end of the Rumble after slowly psyching himself up backstage during the tough main event, he gets slapped about a bit by the harsh wine conditions and released his smelly aroma from his band-aids.
Let's leave WWF behind for a bit now.
How can I control Brett? It's a tough one, there have been some advances in using chitosan lately, as well as filtration. Filtration arguably removes some of the complexity bought into a wine, and can alter its charm that the winemaker has so painstakingly worked towards, but this seems to be a simple option to carry out. Proper winery cleanliness, use of SO2, and good QA practise are certainly the best remedies for Brett. A proactive approach as opposed to reactive is generally the mantra for all winemaking activity. This is no different when considering yeast "spoilage".
Posted by Matthew brown