From a certain point of view, winemakers don’t make wine; yeast and bacteria do. Juice becomes wine by the miracle that is fermentation, the conversion of sugar to alcohol and other compounds. Since I’ve yet to see a human person ingest sugar and expectorate alcohol (whoa…don’t follow that mental image), winemakers must delegate this key operation to yeast.
Open a refrigerator in the back of many wineries and you may find some leftover pizza, cheese and fruit for tomorrow evening’s mixer, and a few rectangular foil packages that look suspiciously like bread-baking yeast. However, those packages of yeast—and they are yeast—are for the wine, not bread dough.