Between The Vines

Yeast: Tiny organism has a big impact on winemaking

Growing up in an Italian family, I was accustomed to a dinner table graced with homemade bread and wine.

I have memories of making pizza dough with my mother, and carefully adding water to the yeast and seeing it become foamy was one of my favorite parts of baking. Watching my uncles crush grapes, fill vats with juice and sprinkle a little dried yeast over the top to make wine is such a strong memory that is sparked my desire to become a winemaker.

In winemaking, yeast is responsible for fermentation. As the yeast consumes the sugar in the pressed grape juice, it generates alcohol, carbon dioxide and heat. While grapes do have indigenous yeast spores that can induce fermentation, many wineries choose to inoculate their juice with commercially available yeast so that they have greater control over the winemaking process. That’s what we do here at Silverado Vineyards.

There are many varieties of winemaking yeast available. Each particular type of yeast is capable of imparting slightly different aromas to the finished wine, with white wines benefiting the most from the subtle effects of these yeasts. Some wines are even enhanced by inoculation with multiple varieties. For instance, we use three different yeasts when fermenting our Silverado Vineyards Sauvignon Blanc. To do this, we separate the freshly pressed juice into three smaller fermentation tanks, inoculating each with a different type of yeast. As we monitor the progress of the fermentation, we can actually see and smell that the juice in each tank is reacting a little differently from the others. To me, that’s one of the more interesting parts of winemaking.

Our winemaking staff has a lot of fun picking out which strains we’re going to use each year, because we do a lot of experimentation, trying different yeasts with different varietals. Every year we receive a catalog detailing the different yeasts that are available. Some strains have names that speak to famous wine regions such as Montrachet and Champagne while others, such as VL3 and D254, are less romantic. For us, paging through the catalog is almost like receiving a huge box of See’s candy – we want to try them all!

We experiment with a wide array of yeasts as part of our never-ending quest to make the best wines possible. When you are making wine at the quality level we are here at Silverado Vineyards, it’s all about the little things. By carefully matching the best yeast to each varietal we produce, the yeast actually becomes a “secret ingredient” that imparts flavors that are unique to Silverado Vineyards wine. In this way we are able to produce premium, fruit-forward wines that really show off the qualities that each of our vineyards has to offer.

Cheers,

Elena Franceschi
Assistant Winemaker