Steve Matthiasson talks terroir at Texas Wine School. Steve Matthiasson of Matthiasson Wines was the speaker at the Houston Sommelier Association on Wednesday at Art of Cellaring . He brought five single vineyard Napa Valley Cabernet Sauvignon barrel samples from the 2021 vintage to taste and discuss with Houston wine professionals. "There's a lot of mystery in terroir," stated Matthiasson, "but it's not random, it's the differences in the land." Napa Valley's proximity to the cold Pacific Ocean allows for many vineyard areas to enjoy the moderating affects of cool breezes and fog coming through which lower temperatures, some areas are heavily influenced by this terroir aspect, Steve explained, while others are not. The majority of the year, water temperatures stay in the lower 50s (degree Fahrenheit) cooling the surrounding air which pushes into the Napa Valley through the Carneros AVA in the south. This is caused by the Great Pacific Upwelling ...