# Blind wine tasting

Blind or blinded wine tasting is a method of wine tasting in which the tasters evaluate wines without knowing their identities. This approach aims to ensure objectivity by eliminating potential biases from visual cues, such as bottle labels, price, geographic origin, or producer reputation. Blind tasting is widely used in professional wine competitions, sommelier certification exams, and academic research to assess wine quality and explore sensory perception.
Techniques for blind tasting vary in complexity, from simply concealing bottles to using black glasses and randomized serving orders to mask all identifying features. Studies have demonstrated that blind tasting can reveal biases, such as the influence of price or appearance on perception, but it is also recognized as a tool for improving sensory evaluation skills and fostering expertise.
Notable examples of blind tasting include the 1976 Judgment of Paris, where California wines unexpectedly outperformed French wines in a blind competition, transforming the global wine industry. Blind tasting continues to play a critical role in wine education, competitions, and research, promoting fairness and advancing understanding of wine evaluation.

## Techniques and practices

Blind tasting techniques aim to remove biases and enhance objectivity in wine evaluation, making it a critical practice in both the wine industry and academic research. Towards this goal, the act of setting up a blind wine tasting involves procedures designed to prevent tasters from knowing the identity of the wine they are evaluating. This approach is employed in professional wine assessments, competitions, and research to ensure impartiality and eliminate external influences such as labels, price, or geographic origin.
At its simplest, blind tasting involves concealing the wine label or bottle shape to obscure identifying information. In informal settings, this can be achieved by covering bottles with plain paper bags or decanting the wine into neutral containers.
More advanced setups are often used in professional or scientific contexts, such as using black or opaque glasses to mask the wine's color, preventing visual cues from influencing the taster's judgment. The wines are typically served in a randomized sequence to minimize the impact of prior expectations or comparisons, and if labeled at all, are labeled with anonymized codes to prevent recognition based on familiar patterns or numbering. Some protocols involve presenting the same wine multiple times to test the consistency of tasters' evaluations, as it has been found that identical wine samples can sometimes be judged differently over the course of a session.

### Applications

Blind tasting is used across various contexts:
* Competitions: In wine competitions, blind tasting ensures impartiality when awarding medals and distinctions.
* Education: Blind tasting is a core component of training for sommeliers and wine professionals, teaching them to focus on sensory characteristics without the influence of branding or reputation.
* Research: Scientists use blind tasting to study sensory perception and consumer preferences, often exploring the impact of external factors on wine evaluation.

## Biases

Blind wine tasting is designed to mitigate biases that may influence a taster's judgment, such as knowledge of the wine's geographic origin, price, reputation, or visual appearance. Numerous studies and experiments have demonstrated the powerful impact of these biases on perception and evaluation.

### The power of suggestion

Scientific research has shown that the power of suggestion and pre-existing expectations can significantly affect sensory experiences. For example, people generally expect more expensive wine to taste better than cheaper wine. In one study, participants were presented with the same mid-range Bordeaux in two different bottles: one labeled as a cheap table wine and the other as a grand cru. The "grand cru" was described as "woody, complex, and round," while the "table wine" was called "short, light, and faulty."
Similarly, Frédéric Brochet's experiments demonstrated how visual information influences perception. When tasters were given a white wine, they used descriptors such as "fresh, dry, honeyed, lively." However, when the same wine was dyed red, participants described it using terms typically associated with red wine, such as "intense, spicy, supple, deep."

### Visual bias

Color is one of the most influential factors in wine evaluation. In a 2001 study at the University of Bordeaux, undergraduate oenology students described the aroma and taste of a red and a white wine. Both wines were actually the same, but the white wine had been dyed red with a flavorless colorant. Despite this, students provided entirely different descriptions for each, demonstrating the strong effect of visual cues on perception.

### Geographic and price bias

Geographic origin and price also strongly influence wine evaluations. In one experiment conducted at Texas A&M University, participants tasted wines labeled "France," "California," and "Texas." Nearly all ranked the "French" wine highest, but in reality, all the wines were the same Texas wine.
A well-publicized study by Prof. Richard Wiseman revealed similar biases regarding price. In a double-blind tasting experiment involving 400 participants, general consumers were unable to distinguish between expensive and inexpensive wines. Wiseman concluded, "People just could not tell the difference between cheap and expensive wine."

## Historical results

Blind wine tastings have played a significant role in exploring the capabilities and limitations of wine tasters, influencing both industry practices and sensory research. Events and studies have highlighted the potential of blind tasting to challenge assumptions about wine quality and reveal the impact of sensory training.

### The Judgment of Paris

One of the most famous examples of blind tasting is the Judgment of Paris in 1976, which challenged long-held assumptions about the superiority of French wines. In this competition, a panel of French judges blind-tasted wines from France and California, with the expectation that the French wines would dominate. However, California wines were rated higher in both red and white categories, an outcome that surprised the judges and the wine world.
The event had a transformative impact on the wine industry, elevating the reputation of New World wines and prompting a reassessment of traditional practices in France. The competition was documented in George M. Taber's book Judgment of Paris and served as the inspiration for the 2008 film Bottle Shock.

### Professional competitions

Blind tasting is a cornerstone of professional wine competitions, ensuring that evaluations are impartial and based solely on sensory attributes. While research has shown variability in the ratings of individual judges, systematic training can enhance accuracy and consistency. One study analyzed the reliability of judges by presenting identical wine samples multiple times and found mixed results. Some tasters demonstrated high skill levels, while others showed significant inconsistencies. In contrast, another study conducted with the Oxford University Blind Tasting Society demonstrated that systematic training significantly improved the ability of participants to identify wine characteristics with greater consistency.

### Consumer studies

Blind tastings are also used to study consumer preferences and perceptions. Research has shown that non-expert tasters are often influenced by external factors such as price and branding. For instance, Richard Wiseman's double-blind tasting experiment found that participants could not reliably distinguish between expensive and inexpensive wines.
Other research has revealed differing patterns between experts and non-experts. A 2008 study analyzing over 6,000 blind tastings found that non-expert tasters tended to rate more expensive wines slightly lower than inexpensive ones, while expert tasters showed a non-negative correlation between price and preference. This suggests that expertise may enhance appreciation for the qualities found in higher-priced wines.
Blind tasting has also been shown to aid in sensory skill development. A 2020 study on perceptual learning in chemical senses found that systematic practice and training can transform non-experts into skilled tasters. The study demonstrated that participants who regularly engaged in blind tastings improved their ability to detect and identify sensory attributes, highlighting the role of blind tasting as a tool for developing expertise.