How climate change could affect the microbes that ferment grapes and give wine its specific flavours

By Stephen On, Lincoln University, New Zealand, Manpreet K Dhami, Manaaki Whenua - Landcare Research

The far-reaching consequences of climate change inevitably include the production of foods and beverages, including wine.

In New Zealand, winemaking is an important business, with exports worth more than NZ$2 billion per year.

Earlier studies have already suggested that grapevine characteristics such as flowering and grape sugar ripeness may be linked to climatic changes. But so far, the microbes that ferment grapes have received little attention.

Our new research explores how yeasts, bacteria and fungi may be affected by changes in temperature and rainfall.

Microbes, wine and the coveted gold star

Without microbes, all we have is grape juice.

It is well established that individual strains of yeast (most commonly Saccharomyces cerevisiae) used to ferment grape juice into wine play a major role in the generation of a range of chemical compounds that influence the flavour, aroma and mouthfeel of wine. A “good” strain (or strains) can mean the difference between a gold award or a bottle of plonk.

Conventional commercial winemakers tend to use established strains from yeast suppliers to provide increased assurance for their production schedule and consistency of the final product. Nonetheless, inevitably every batch of juice will already possess its own diverse community of microorganisms, some of which will begin exerting their own influences upon the wine as it develops.

Some winemakers choose to eschew the addition of commercial yeast, relying on the native microflora in and on the grapes to do the job. This process can be referred to as either spontaneous or “wild” fermentation.

In such cases, the role and diversity of these microbes is critical in the development of the wine, and to its quality. Various studies have demonstrated that the microbial populations in a given winemaking region can be distinctive, contributing to the terroir of the wine.

Read Full Story https://theconversation.com/how-climate-change-could-affect-the-microbes-that-ferment-grapes-and-give-wine-its-specific-flavours-225997