Episode 309 of I’ll Drink to That! has been released and it features grape geneticist Carole Meredith, co-proprietor of Lagier-Meredith Vineyards in Napa.

This interview feels like sitting down with a detective to talk through the most important cases, except in these cases the suspects were grapes. Carole Meredith and the colleagues she worked with realized that markers in plant DNA could be used to identify grape vine parentage. This realization led them on a search for the parents of some the most well known grapes in the world, such as Cabernet Sauvignon. In an early success they identified Cabernet Franc and Sauvignon Blanc as the parents of Cabernet Sauvignon. But many times a parent was less well known, such as Gouais Blanc, an ancestor of not only Chardonnay, as it turns out, but also of Pinot Blanc and Romorantin. Carole discusses why these couplings have happened. In the case of Gouais Blanc, it was planted nearby Pinot Noir vineyards in Burgundy, because while the nobility and the monasteries had Pinot Noir on the slopes, the serfs working those vineyards in feudal times had the Gouais that they used for their own home winemaking planted near their villages in the region. The proximity of Pinot Noir and the Gouais, which was most likely of Eastern European origin, led to the eventual crosses, of which there were several. These are the kinds of histories that had been unknown before Carole Meredith’s work, and she is an enthusiastic tour guide of vine history as she relates what she found while working as a Professor of Grape Genetics at the University of California Davis. If you are curious about just how old Zinfandel actually is, or the likely birthplace of Syrah, definitely give this episode a listen.

Listen to the stream above, or check it out in iTunes.

I’ll Drink to That is the world’s most listened-to wine podcast, hosted by Levi Dalton. Levi has had a long career working as a sommelier in some of the most distinguished and acclaimed dining rooms in America. He has served wine to guests of Restaurant Daniel, Masa, and Alto, all in Manhattan. Levi has also contributed articles on wine themes to publications such as The Art of Eating, Wine & Spirits magazine, Bon Appetit online, and Eater NY. Check out his pictures on Instagram and follow him on Twitter: @levi_opens_wine