Where in the world is Brett?

Where in the world is Brett?

By Gilbert Labour ©

At the recent 2003 Murrumbateman Cool Climate Wine Show an unacceptably high level of wine taint was noted by the judges. Whilst spoilage by the more commonly recognised TCA was, thankfully minimal, an outbreak of Brettanomyces tainted wines was evident

What then is Brettanomyces?

It is a yeast borne micro organism that is universal to all wine making regions. It can be acquired through contact with soil and grape skins in vineyards, in crushing equipment and it can be propagated by fruit flies. It is all pervasive and once it has penetrated the wood grain in barrels, it is virtually impossible to be rid of. Surprisingly, new barrels have more potential to support higher levels of the contaminant, perhaps due to the larger pore size in the staves.

Brettanomyces [Brett for short] does not discriminate between red and white wines. However, in red wines it affects very specifically the volatile compounds. There are 3 components to Brett and they reflect themselves very differently.

For the scientifically minded, the components are: 4 – Ethyl – Phenol [4EP], 4 – Ethyl – Guaicol [4EG] and IsoValeric Acid. Varying concentrations of each component impart different taint spectrum and will affect the flavours & aromas differently. In combination, they devastate the wine. 4EP shows up as horsy, leathery, band aid flavours. 4EG as clove, spice and “bushfire “ smokiness.ISO Valeric Acid is the hardest to pin down, but can be sometimes detected as dank, tankish and barnyardy.

How does Brettanomyces work?

In general, Brett produces an Esterase activity which spoils the fruit esters. These are the compounds that give the fresh fruity lift to wines, thus leading to a deadening of freshness. It also dulls the taste buds in the palate, cheek, and tongue for quite a while afterwards.

Why is Brett manifesting itself so much more prominently these days?

Modern wine making styles and market demands for “healthier !! “ wines have led to a decrease in the use of sulphur as a stabilizing and sterilizing agent.

On the one hand a decrease in free sulphur improves mouthfeel and lessens the incidence of intolerance to sulphides especially for asthmatics.

However, on the other hand, low levels of free sulphur encourage proliferation of Brett.

Historically, some may argue, Brett has been around since the Gauls invented wooden barrels for wine storage and a school of thought attribute the classical Hunter Valley “sweaty saddle” character in red wines to nothing more than Brett taint. In some areas of France, winemakers deliberately blend some Brett – affected reserve wine to their new vintages as they believe that a small amount of Brett adds character and an extra dimension to a wine. But how much is the right amount ?

There are wine makers like Don Young of Orlando Wyndham, a judge at the 2003 Murrumbateman Cool Climate Wine Show, who is a zealous believer that the only good Brett is dead Brett. He propounds that there is absolutely no place for Brett in modern wine making as uncontrolled Brett can be and indeed has been used as an excuse for poor vineyard management, less than scrupulous winery hygiene and sloppy winemaking. Young’s protocol starts with heavy sulphuring in the vineyard followed by high levels of sulphur during fermentation, stabilization, and bottling under sterile filtering. The amount and frequency of application would, of course vary with site and vintage conditions. This regime harks back to the older days of Australian wine making when sulphur was used aggressively and liberally, without detriment to the product.

So, where in the world is Brett? Everywhere it would seem.