Where brett in wine comes from - ask Decanter

Ask Decanter

Does brettanomyces develop over time? David Bird MW gives his point of view to Decanter.

Where brett in wine comes from – ask Decanter

Howard Davis, from Birmingham, asks: Does brettanomyces develop over time? I find a little quite nice, but I’ve tasted some Rhône Syrahs and Roussillon red blends that to me have really unpleasant levels. I wonder how producers can be allowed to sell wine with such extreme levels, unless it is a fault that happens in bottle or with age?

David Bird MW, for Decanter, replies: Brett infections occur in the winery when the wine is being made.

The yeast that causes it is one of many strains used in winemaking and its presence at low levels is actually beneficial, adding extra complexity. Sensitivity towards the taste effect produced by this yeast varies greatly from person to person – some find it disgusting, while others think it quite attractive.

As this change in the wines’ character is caused by an infection, tight filtration should remove the agent, thus preventing further change in the bottle. On the other hand, with the rise in popularity of natural winemaking, using neither fining nor filtration, it is possible that microbiological activity could continue after bottling.

As this is a personal preference, it would be hard to introduce any control on acceptable levels – chacun à son goût.

David Bird MW is a wine consultant and author of Understanding Wine Technology.