Wine experts will describe the various factors that contribute to the wine terroir – the taste of a wine. It’s the environmental factors that are said to have a character; the terroir.

The concept of terroir originated in France due to the observable differences in wines from different regions, vineyards and even within of the same vineyard. Microbiologists have added to the picture by studying the microbiology of the wine-making process in fine detail; it appears wine terroir is largely dependent on the collection of microorganisms related to the grape and fermentation process – the so-called microbiome.

Wine Terroir & Microbiome

A recent US study aimed to describe microbial diversity in wine must, which is freshly pressed grape juice, as it proceeded through fermentation. Like much of modern microbial ecology, high-throughput gene sequencing was employed on hundreds of must and wine samples from eight stages of the fermentation process. The data generated were used to assemble descriptions of the samples’ microbiomes.

The researchers proceeded to align distinct microbiomes recovered from the musts to the metabolome of the finished wines (The metabolome is the complete set of small-molecule chemicals found within the wine).

One outcome of the analyses was the observation of the dynamic nature of wine microbiomes – population structures change throughout the wine-making process. The implications of the study’s outcomes may extend to dictating the flavour of wine by managing the microbial influences.