Stains go high-tech: Unilever updates Persil and Surf as Gen Z's matcha obsession spurs data-driven product design

Unilever said it will bolster the formulas behind Persil and Surf after a data-driven assessment found matcha stains are the most persistent emerging stain among Gen Z. The findings come from the company's annual Stains Index, released December 15, 2025, which tracks how new pigments and residues enter everyday life and what that means for cleaning products. The move underscores how consumer lifestyles are driving a more tech-forward, data-driven approach to product development in the laundry category.

The Stains Index surveyed 2,000 adults and ranks emerging stains based on reports of more frequent staining over the previous year. Gen Z, born roughly between 1997 and 2012, accounts for the most pronounced upticks in matcha spills, while other items on the list include Aperol Spritz, lipstick and bronzer, protein shakes and sports drinks, bubble tea, nail polish, sriracha or hot sauce, deodorant, makeup/foundation, glitter, and pollution/dust. The report notes that the shift from mud and grass stains to stains from modern beverages and cosmetics reflects urban living and evolving routines. The study also found that 39% of respondents said they had more matcha-related staining than in the prior year, and matcha stains leave a bright green mark that can be stubborn for older formulas.

Donna Macnab, Unilever Laundry R&D Director, said stains mirror contemporary lifestyles and the pigments people encounter in daily life. “Stains provide an interesting reflection on our lifestyles and routines,” she said. “As we see new pigments and residues emerge as a result of modern–day living, we test new formulas and adapt our products, so they remain at the cutting–edge of stain removal. For 2026, that testing will now include the Stain of the Year – matcha, which has been identified as the stain Gen Z are tackling more frequently, particularly over the past 12 months.”

The Port Sunlight Laboratories, where the formulas of Persil and Surf are fueled by ongoing testing and development, are at the center of the update. Unilever said their work aims to “keep pace with modern lifestyles” by strengthening stain-removal performance against the new and evolving marks left by contemporary foods and beverages. The company added that the Stains Index will be updated each year to monitor how stains evolve among UK consumers and to inform future product design.

Beyond matcha, the Stains Index highlights a broader shift in stain patterns among Gen Z. The top stains listed for emerging concerns include matcha (39%), Aperol/Cocktails (38%), lipstick/bronzer (37%), protein shakes/sports drinks (35%), bubble tea (35%), nail polish (35%), sriracha/hot sauce (34%), deodorant (33%), makeup/foundation (32%), glitter (32%), and pollution/dust (32%). The ranking reflects a data-informed lens on daily life, where cosmetics, specialty beverages and pollutants intersect with laundry outcomes. The findings come as brands increasingly tie product development to consumer analytics and real-world usage data to stay competitive in a fast-changing market.

The Stains Index also provides a window into Gen Z’s daily decisions. Poll results show that 79% of Gen Z respondents worry about staining clothes when choosing what to eat or drink, and more than half say they have selected menu items purely because they looked appealing on social media, even when that choice increases the possibility of a stain. In practical terms, the data suggest a higher freedom-to-stain dynamic among younger consumers that brands must address with more resilient formulations and smarter cleaning solutions. The survey also found that about 70% of Gen Z stain their clothes on a weekly basis, compared with 47% of Boomers, and 91% have discarded clothing because of stubborn stains. These insights help explain why Unilever emphasizes annual updates to its stain-index methodology and why the Stains of the Year category will matter for product strategy in 2026 and beyond.

The emphasis on data-driven product design marks a broader trend in Technology & AI-adjacent consumer goods, where cleaning formulations are increasingly guided by analytics, consumer behavior signals, and real-world usage patterns. By weaving the Stains Index into ongoing R&D, Unilever aims to anticipate new stains before they become widespread consumer pain points and to deliver detergent formulas that perform at the cutting edge of stain removal in a fast-evolving cultural landscape.