Analytical Testing in Wine Making: Transform Quality Control Into Quality Design

Winemaking is a centuries-old craft, rich in knowledge about the conditions that transform grape juice into wine that has been garnered from meticulous experimentation with yeast-driven fermentation. Building on that knowledge, wineries around the world have created the vast spectrum of wine styles we enjoy today. By combining grape varieties, yeast strains and additives in well-defined, carefully monitored production processes, vintners create unique combinations of flavor, aroma, color and clarity.

That diverse repertoire of wines also reaches every corner of the globe. Customers have an expansive choice of brands – a testament to the stark competition in the market. Succeeding in this crowded landscape means retaining customer loyalty by offering the same great wines year after year. The need to attain that level of consistency and reproducibility in production, despite the complex interactions that impact winemaking outcomes, has brought advanced analytical technology onto the manufacturing floor of wineries worldwide.

A shift from quality control to quality design

Quality control has always played a pivotal role in the production of wines. Global, national and local regulations stipulate permissible production strategies like the use of additives and processing aids, as well as labeling requirements for several components that may be present in a wine. Accredited food analysis and safety laboratories have supported the wine industry in meeting legislation requirements, quality standards, and import/export guidelines through biochemical analysis services.

However, winemaking is a delicate process where the composition of grape juice and must, as well as unexpected changes during fermentation, clarification, racking or aging can quickly de-rail the development of a wine. Time is of the essence when creating premium wines. Wineries have, therefore, relocated several aspects of quality control to onsite laboratories (Figure 1) and established in-process analytical testing strategies that transform quality control into quality design.

With direct access to data on critical biochemical parameters of production, vintners can now rely on more than experience and lessons learned to maneuver the winemaking process. Thanks to onsite laboratories and advanced yet easy-to-use analytical instruments, what used to be occasional checks and partial glimpses into the status of a fermentation vat or aging in a barrel is now a systematic biochemical profiling of the wine at every stage of its evolution – from raw grapes to a bottle ready for sale.


Figure 1. Analytical wine testing commonly done onsite.

Informed, on-time decisions make quality wines

In winemaking, the outcome of every production stage is the starting point for the next. As such, at each transition, a vintner must decide exactly when to move to the next step and whether a batch should be carefully adjusted to keep it biochemically on track. Data from analytical testing performed at each of these decision points arms the vintner with a detailed profile of their craft to better anticipate deviations that can spoil a batch and steer or even enhance the quality of the final product.

During the first production stages, knowing the sugar and organic acid content of grapes helps determine the best harvest time and optimize the mixture of grape varietals that will initiate fermentation with the right sugar-to-acid ratio to reach the target final gravity. Additives mixed into must promote fermentation and control pH. Which additive, and how much to supplement (so that pH imbalances do not jeopardize color, flavor and microbial stability), depends on knowledge of the organic acid and nitrogen content of must. Similarly, dissolved oxygen and sulfur dioxide are monitored from fermentation through to bottling to keep oxidation and microbial activity in check, both of which lower wine quality.

Modern, advanced analyzers for wine testing are designed for the high wear-and-tear of a winery manufacturing site. Easy to use, highly reliable and available in formats that allow the manual measurement of chemistry at individual barrels or hands-off testing of several hundred samples, these devices are a good investment to incorporate quality checks directly into production processes. The exact setup of an onsite analytical lab, and the type of instruments to purchase, will depend on the amount and type of wines produced. A careful evaluation of the points in the winemaking process, where data is important to inform next steps, helps plan an overall in-process testing strategy and better match analyzers with the number and types of tests that need to be performed.

Premium wines by design – the intersect of quality, scale and brand

Data from analyzing samples don’t just complement a vintner’s intuition and knowledge to ensure that the quality of wines meets regulatory requirements. Ultimately, the data empower a winery to establish a robust and efficient manufacturing process that is scalable to commercially meaningful volumes with healthy profit margins in a highly competitive market. The key to that scalability is safeguarding reproducibility. Measurements of critical biochemical parameters along the complete production process serve as benchmarks to ensure that every step is on track to achieve stylistic and quality goals. Furthermore, any deviation is detected early and enough information is provided to enable corrective action in time to rescue a batch. In this way, the defining qualities of a wine – its acidity, sweetness, flavor, tannin levels and body – are, in fact, meticulously designed and thus repeatable year after year.

Perhaps the most powerful aspect of approaching the quality of a wine as an attribute that is designed rather than controlled is its impact on brand. Customers return to a particular wine because they expect the same aroma, taste and appearance every time. Keeping a promise to deliver that same experience consistently from bottle to bottle is the very definition of brand. Therefore, investing in advanced analytical instrumentation and a robust, thorough testing strategy is investing in the name of a winery. It is nothing less than ensuring that the logo of a winery proudly certifies a bottle as a crafted premium wine – by design.

Author biography:

Ricki Hartwell is a senior product manager within the Water Lab Products division at Thermo Fisher Scientific and is responsible for new product development, lifecycle management, competitive analysis, product positioning, and global commercial trainings.  She holds a bachelor’s degree in Biochemistry and Molecular Biology from Boston University.