Practical Applications & Economic Benefits
By: Andreea Botezatu, PhD – Department of Horticultural Sciences, Texas A&M University
Verjus, an acidic juice derived from unripe grapes, has a history dating back to ancient Persia and the Middle East, where it was prized for both culinary and medicinal purposes. Today, it is gaining renewed attention in the winemaking industry as a sustainable and versatile tool. Known for its culinary applications, verjus also offers practical advantages for addressing challenges such as high pH and low acidity in wines from warmer regions affected by climate change. This article talks about the history, health properties, winemaking applications, and economic benefits of verjus, highlighting its potential as both a winemaking aid and a standalone product.
History and Health Properties of Verjus
Originating from the French term “vert jus,” meaning “green juice,” verjus has been a staple in European cuisine since the Middle Ages. It was extensively used in sauces, condiments, and for deglazing dishes. In Middle Eastern cuisines, such as Lebanese and Persian, verjus—known as husroum and ab-ghooreh, respectively—remains integral, especially in dishes like Shirazi salad. Currently, verjus is seeing a resurgence in the western world, being particularly popular with mixologists who use it to enhance acidity and flavor complexity in various cocktails and mocktails.
Historically, verjus was believed to possess medicinal properties, including immune system stimulation, reduction of stroke risk and high cholesterol, and promotion of liver health. Rich in antioxidants and organic acids, it has been linked to digestive health, anti-inflammatory effects, and the reduction of oxidative stress.
Modern scientific research reinforces these benefits, identifying bioactive compounds such as phenolic acids, flavonoids, and tannins in verjus. These compounds not only enhance its health-promoting properties but also contribute to its antioxidant capacity, which can improve wine stability during aging.
High pH Challenges
Hot climates like Texas pose significant challenges for winemaking due to the natural ripening process of grapes under high temperatures. In these conditions, sugar accumulation accelerates while malic acid levels decline, resulting in grapes with high pH and low acidity. These characteristics can lead to microbial instability, lack of freshness, and diminished wine quality. Verjus, derived from unripe grapes, offers a natural and sustainable solution. Its high acidity and balanced organic acid composition make it an effective tool for lowering pH and improving wine stability and sensory quality. By utilizing grapes typically removed during cluster thinning, verjus not only addresses the challenges of high pH but also enhances sustainability in vineyards and wineries.
Verjus as a Winemaking Tool: Chemical and Sensory Impact of Verjus
Verjus’s unique composition offers a valuable and sustainable alternative to conventional acidifiers in winemaking. Its high acidity, low sugar content, and pH ranging from 2.2 to 2.7 make it especially suitable for addressing the challenges of high pH and low acidity in wines, issues that are increasingly prevalent in warm-climate wine regions. Key components of verjus include significant levels of organic acids (malic and tartaric acids), phenolic compounds, and antioxidants, which collectively enhance its functionality in winemaking.
1. Acidity Adjustment: Verjus is highly effective in lowering pH and increasing titratable acidity in both musts and finished wines. Studies on varieties such as Muscat Canelli and Syrah have demonstrated that pre-fermentation additions of verjus ranging from 11% to 17.5% by volume achieved optimal pH levels for balanced wines. For instance, in a trial with Syrah, the addition of verjus reduced the pH from an initial 4.16 (indicative of poor stability and susceptibility to microbial spoilage) to a desirable 3.60, resulting in improved mouthfeel, color stability, and overall wine quality. Similarly, in Muscat Canelli, verjus effectively reduced pH while elevating titratable acidity, ensuring wines exhibited enhanced freshness and vibrancy.
2. Alcohol Reduction: Replacing a portion of ripe grape juice with verjus during fermentation not only addresses pH issues but also reduces total sugar content. This leads to a decrease in the alcohol content of the resulting wine, making verjus a natural tool for producing lower-alcohol wines.
Lowering alcohol levels in wine has become an increasingly desirable goal for several reasons. Globally, organizations like the World Health Organization (WHO) advocate for reducing alcohol consumption as part of broader health initiatives, citing concerns about excessive alcohol use and its impact on public health. In parallel, consumer preferences are shifting, with a growing demand for lower-alcohol and non-alcoholic beverages. This trend is driven by health-conscious individuals, those exploring “mindful drinking,” and sober-curious consumers who seek wines that offer full flavor without the high alcohol content. By allowing winemakers to reduce alcohol naturally, verjus aligns with these evolving market trends. For example, in Muscat Canelli trials, an 11% verjus addition reduced the alcohol content from 14.3% to 13.2%, while preserving the sensory integrity of the wine.
3. Sensory Quality: Extensive sensory evaluations indicate that wines acidified with verjus are indistinguishable in terms of consumer preference from those treated with traditional acidifiers like tartaric acid. In studies involving industry professionals and consumers, no significant differences in overall preference were found between verjus-treated wines and their conventionally acidified counterparts. This underscores the versatility of verjus as an acidifier that enhances wine chemistry without compromising sensory appeal.
4. Enhanced Profiles: Beyond acidity correction, verjus contributes valuable phenolic compounds that improve the antioxidant capacity of wines. These compounds can also enhance aromatic complexity, particularly in aromatic white wines like Muscat Canelli. In addition to its role in balancing acidity, verjus has the potential to elevate a wine’s sensory profile, creating products with greater depth and intrigue for discerning consumers.
5. Applications in Red & White Wines: Verjus is highly versatile and suitable for use in both red and white winemaking. In red wines, such as Syrah, verjus additions not only corrected pH but also improved structural elements like mouthfeel and color stability. In white wines, such as Muscat Canelli, the heightened acidity imparted by verjus enhanced perceived freshness, as confirmed by both chemical analysis and consumer panel feedback. These results highlight the adaptability of verjus for different wine styles and its potential to improve quality across a wide spectrum of varietals.
Verjus as a Standalone Product
Beyond its winemaking applications, verjus has significant potential as a standalone culinary product. Its uses include substituting for vinegar or lemon juice, deglazing pans, creating salad dressings, and complementing delicate flavors in sauces. Verjus is also gaining popularity in non-alcoholic beverages and cocktails.
For wineries, selling verjus as an artisanal product presents a lucrative opportunity. Premium packaging and marketing can position verjus as an eco-friendly and health-conscious choice, appealing to chefs and consumers alike. By diversifying product lines, wineries can maximize grape harvest value and enhance brand recognition.
Two recent studies from Texas A&M enology professor Andreea Botezatu and her graduate students have taken a closer look at the applicability of verjus in the winemaking process as an acidifier, both from a technical and economic perspective.
The first study (Effects of verjus acidification on muscat canelli grape juice and wines) explored the use of verjus, derived from unripe grapes, as a sustainable and effective acidification agent for winemaking. Conducted in Texas, the research targeted high pH and low acidity issues prevalent in wines from warm climates. The authors produced verjus by harvesting unripe Muscat Canelli grapes during cluster thinning. The grapes were destemmed, pressed, and the resulting juice was cold-settled and analyzed for chemical composition. Verjus was then stored at 5°C until it was blended with ripe grape juice.
Three treatments were prepared: a control with no verjus, a 2% verjus addition (0.2 L per 8.5 L juice), and an 11% verjus addition (1.1 L per 10 L juice). Each treatment underwent fermentation with standardized yeast and nutrient protocols, followed by racking, filtration, and bottling. Chemical analyses measured pH, titratable acidity, malic acid, tartaric acid, alcohol, polyphenols, and potassium.
Sensory evaluations were carried out during four industry events, involving 218 participants, who ranked the wines based on preference and acidity perception. Results showed that verjus addition significantly reduced pH and increased titratable acidity, malic acid, and tartaric acid levels. The treatment with 11% verjus brought the wine’s pH to 3.3 (from a control of 3.6) and increased acidity to 7.1 g/L. Verjus-treated wines also exhibited lower alcohol levels due to dilution, with the 11% treatment reducing alcohol from 14.3% to 13.2%. Importantly, sensory evaluations found no significant differences in preference between verjus-treated wines and the control, ensuring that verjus acidification did not compromise wine quality. These findings underscore verjus’s potential as a sustainable solution for improving wine quality in regions impacted by climate change.
The second study (Evaluating the Economic Feasibility of Verjus Production in Texas Vineyards and Wineries) examined the economic feasibility of using verjus in winemaking and as a standalone product. The research assessed production costs, revenue potential, and sustainability benefits. The authors modeled the process using high-yield grape varieties such as Sangiovese and Tannat, estimating that one ton of unripe grapes could produce approximately 378.5 liters of verjus. Economic calculations incorporated labor for cluster thinning, transportation costs, and equipment for processing and bottling.
In winemaking, verjus was evaluated as a substitute for tartaric acid to acidify wine. To reduce pH by 0.25 units, approximately 100 mL of verjus was required per liter of wine. While verjus was more expensive than tartaric acid (USD 0.30 per liter vs. USD 0.02 per liter), the associated 10% increase in wine volume generated significant additional revenue. For 3785 liters of wine, the added volume contributed USD 5639 in revenue, making verjus economically advantageous.
The study also analyzed the feasibility of bottling verjus as a gourmet product. The breakeven cost for producing a 750 mL bottle was calculated at USD 6.98, with retail prices reaching USD 12, yielding substantial profit margins.
Together, these studies illustrate the chemical, sensory, economic, and environmental benefits of incorporating verjus into winemaking. They demonstrate that verjus not only addresses challenges like high pH and low acidity but also creates a new revenue stream while promoting sustainable practices in the wine industry. If additional clarifications or deeper insights are needed, feel free to ask!
Conclusion
Verjus represents a sustainable and innovative tool for modern winemaking. Its ability to address high pH and low acidity, improve wine quality, and offer economic benefits through waste reduction and product diversification makes it invaluable. As climate change continues to impact grape-growing regions, adopting verjus as a natural acidifier will be beneficial for maintaining wine quality and industry sustainability.
