Ask Wine Wizard

Dealing With High Brix Grapes


Hunter Nolan — New Braunfels, Texas asks,

My viognier came in at harvest at 28 °Brix. Should I dilute before pitching yeast?

You definitely want to water down that high-sugar juice before you pitch your yeast. High Brixes lead to high alcohols, which lead to yeast that just can’t complete a fermentation. Stuck fermentations are no fun as they almost always lead to wine spoilage. The resulting problems of microbial infection, high VA, and off-odors are truly tragic. Luckily, such winemaking travesties can be largely prevented if we all just begin fermentation with strong yeast and reasonable Brixes. I like white fermentations to begin no higher than 24.5 °Brix, though I’ll always go lower, like to 23.0-23.5, especially if flavors are ripe and the acid needs to be higher like in a Pinot Grigio or a Sauvignon Blanc. Reds can usually go a little higher but don’t go too high. How much alcohol is produced for every degree Brix? Would you believe that there isn’t an easy answer and that this is something winemakers struggle with every year, including me. One rule of thumb is to multiply every degree Brix by 0.56 but I often find that too low. 0.57 tends to
Response by Alison Crowe.