Spain and Portugal are two of the world's most popular wine-growing countries, with regions such as Rioja and the Douro Valley producing millions of bottles every year. This winemaking tradition dates back thousands of years, but its exact origins remain a mystery. To understand how it all started, scientists led by Carolina Royo of the Instituto de Ciencias de la Vid y del Vino in Spain took a step back into the past and studied ancient grape seeds.