December 2009

The Dirty Secrets of High Alcohol Wines, Part Two

by Jack Stuart on December 1, 2009

The Dirty Secrets of High Alcohol Wines, Part Two

Overlooked in the alcohol debates is the amount of manipulation that is required to make high-alcohol table wines. Any must over 25° or 26° Brix needs help to ferment to dryness. With some winemakers aiming at 28° Brix, grapes sometimes arrive in the cellar with Brixes of 30° or more. These musts need to be diluted with water by as much as 15 percent to be able to ferment completely, and they require additions of various nutrients, such as diammonium phosphate, yeast hulls, and thiamin, as many as two or three times during fermentation.

Troublesome fermenters may stick (stop fermenting) anyway, allowing opportunistic bacteria, such as acetobacter and pediococcus, which produce distinctive off odors and flavors, to grow and compete for nutrients. In such cases, complex apparatuses must be brought in to remove acetic acid or alcohol, which inhibit continued fermentation. Sometimes filtration is required to remove viable bacteria. Then the whole mess has to be reinoculated with alcohol-tolerant yeast and more nutrients. At the end, you may still wind up with a beat-up sweet wine.

Now, it’s true that new rootstocks, new spacing, new clones and new canopy management have changed things in the vineyard since the good old days of AXR-1 and 8-by-12 spacing. It may be that we really do have to pick at slightly higher sugars to get the ripeness we desire without losing the character of the variety. It’s also true that lots of Cabernet and other cultivars are being planted in marginal areas that are not suitable, forcing winemakers to leave fruit on the vine longer to diminish the underripe characters that persist on bad sites. One way to tell whether a site is a good match for a particular variety is that you can achieve fruit ripeness at relatively lower Brix levels.

Even so, it may be that 14.5 is the new 13.2. Good wines at that alcohol level can be enjoyed, but go much higher and you start to get into trouble. Such wines are harsh, they make you tired, you can’t enjoy them throughout a meal, and they overwhelm the food.

—Jack Stuart, Winemaker & Partner