Six wines, one closure , one unanimous answer.
A blind tasting built around a single sustainability question: does cork still belong in the closure conversation? The data from one Earth Day evening at Carroll Hall says yes — clearly, unanimously, and faster than expected.
Introduction & Methodology
Why we ran an Earth Day blind tasting about cork.
100% Cork is an educational communications campaign about wine cork stoppers, established by the Portuguese Cork Association with support from the Cork Quality Council to increase awareness of the unique qualities and sustainability of natural cork. The mission of the campaign is to provide the wine industry and consumers with the latest information and research on the benefits of natural cork.
It's indisputable that wine drinkers prefer natural cork. Some know the science — oxygen ingress, non-permeability, fault rates less than 1%. Some understand the environmental benefits — CO2 sequestration, 100% sustainable and renewable. Others just like the pop. But all agree, the nature of wine deserves the nature of cork.
100% Cork is best for wine, best for wine lovers, best for the environment.
On April 22, 2026, No Wine Left Behind hosted a blind tasting at Carroll Hall in Brooklyn, NY, designed to test how a single Earth Day evening could shift guest perception of natural cork. The night ran in two flights — a sparkling rosé plus three whites in Flight 1 (Vilarnau Cava Reserva Rosé Delicat NV, Olianas Vermentino di Sardegna 2024, Vincent Carême Vouvray 'Spring' 2023, Oenops 'Rawditis' Roditis 2022), and two reds in Flight 2 (Loveblock Pinot Noir Central Otago 2019, Tenuta Casadei 'Sogno Mediterraneo' Toscana IGT 2022).
After Flight 2, guests completed a four-question Sustainability Pulse via Paperform: (1) which closure feels most sustainable, (2) whether they previously connected cork with sustainability, (3) whether they'd actively seek cork after tonight, and (4) which closure they'd choose in a same-price, same-style head-to-head. All percentages in this report represent the share of Sustainability Pulse respondents. One internal NWLB submission was excluded; names and individual responses are not surfaced.
The report below is built around three findings from the Sustainability Pulse and a side-by-side visual of how guests' relationship to cork shifted across a single evening. The data is clean, consistent, and tells one story.
Three numbers that tell the whole story.
The Sustainability Pulse asked three additional questions designed to surface change — what guests believed before they arrived, and what they believe now.
The conversion, side by side.
Same guests, two different moments. On the left: what they believed at the door. On the right: what they reported after tasting through the flight and reflecting on the role of cork. The shift was sharp, and it was consistent.
In a single evening, the share of guests actively seeking cork went from a question mark to 67%. Add the "maybes" and the figure is 100%. The closure conversation didn't need a lecture — it needed a flight.
