Wine Word(s) of the Month: Whole-Cluster Would you like a side of stems with that? A sommelier explores how the inclusion of grape stems during fermentation affects the character of the finished wine.

My first deep dive into Pinot Noir was the summer of 2009, when I worked harvest for a storied estate in Burgundy with a winemaking history stretching back over 150 years. Through a colleague, I secured a place on the sorting table, where harmless minutes felt like painful hours. Being a somewhat annoying and newbie sommelier, I asked the Managing Director (and former wine critic) if the estate practiced stem inclusion. With the passion of a fighting tiger, he replied, “Stems! Why the hell would I want to use stems? I would never eat the stems, so why would I put them in my wine?” Fair point.

If the term stem inclusion is not part of your vocabulary, then maybe whole-bunch, whole-berry, or whole-cluster fermentation rings a wine bell. Stem inclusion means that a percentage of fermenting grapes remain intact with their brown to greenish stems, versus being plucked away from them, which would be called destemmed fruit. When we hear these terms, Pinot Noir jumps to the forefront, but other varieties like Syrah, Gamay, Cabernet Franc, Grenache, and even Nebbiolo can experience stem inclusion. One of the main attractions of stem inclusion is added structure. When the stems are physiologically ripe, they can enhance the wine’s structure over the mid-palate and produce a greater drying effect on the finish, two things Nebbiolo doesn’t need. So, there must be something, beyond structure, that winemakers (and drinkers) desire.

It’s important to note that stem inclusion is a dynamic tool for winemakers; it’s not as “black and white” as a percentage of new barrel or time in barrel, which typically commands stricter limits. For those who like the effect of stems, the fermentation recipe changes based on six major elements: the vintage, the personality of the vineyard, the type of clone, the age of the vines, the presence of botrytis, and the quality and ripeness of the stems themselves. In Burgundy, estates like Dujac, de Montille, and Romanée Conti are recognized for using a high percentage of stems (up to 100%). While other estates, like Anne Gros, Ponsot, Nicole Lamarche, and Domique Lafon, eschew stems or use them sparingly. The majority, perhaps figuring out their signature style, fall in the middle, preferring a range between 15-50%. Whether winemakers retain the stems or discard them, it seems like everyone has stems on their mind. So, what’s the tipping point?

“All season long, I’m thinking about whether or not I’m going to use whole-cluster as I walk each vineyard site. Then, I make my final decision at harvest time,” says Katy Wilson, consultant winemaker and owner of LaRue winery in Sonoma, California. “With Pinot Noir, my range is typically 25 to 50 percent, but sometimes I don’t use whole-cluster at all. For instance, if it’s an earlier vintage, I tend not to use whole-cluster”. In New Zealand, Pinot Noir specialist, Ben Glover of Fincher & Co. (in partnership with MW Liam Steevenson) and his family’s business, Zephyr Wines, notices how stems play a very different role in Marlborough versus Central Otago, “We are very vintage dependent and have found that 15 to 20 percent whole-bunch fermentation suits the Marlborough style, particularly in the Southern Valleys, allowing the fruit to still be the hero while giving the wine a strong framework without the aggressive tannin. For Central Otago the fruit can handle a higher proportion of stems. So, we use up to 40 percent there.”

Oceans apart, Wilson and Glover both agree that for their styles of wine, the decision to use stems begins in the vineyard and the clusters must achieve phenolic ripeness to avoid a dominant green tone in the final wine.

So, we know that structure is good and big green tones are bad (a little green can be a good thing), but what about the elusive “X” factor? Wilson likes how whole-cluster fermentation, depending on the site, can enhance the earthy and spicy aromas in Pinot Noir, and in her experience with Syrah, credits the technique with bringing out a softer, white pepper aroma.

From a sommelier’s perspective, Eric Hemer, Master of Wine & Master Sommelier, says his indicators of stem inclusion, beyond more “drying” tannins on the palate, can range from vegetal/woody notes, to dried underbrush, black tea, and spices like nutmeg, cardamom, cinnamon, and black pepper. Whether you smell cardamom or pepper, black tea or red tea, these additional nuances of flavor make us more intrigued, more drawn in when we pick up a glass of wine with stems. If we view structure as the framework to a house and our senses as the eye-catching windows, floor, and paint, then stem inclusion is an essential tool when striving for perfection, complexity, and beauty in a wine.

Like most wine tools, stem inclusion is far from “right or wrong.” From Burgundy to Sonoma to the dead quiet basins of Central Otago, winemakers pay attention to many variables when making their choices about stems, for every vineyard, during every harvest. It’s important not to get buried and caught-up in all the numbers, because as Wilson states, “When it’s done really well, it’s kind-of hard to tell.” So, the next time someone asks me for a side of stems, I’ll trust the chef and gladly say yes.

Allegra E. Angelo is a sommelier and partner of Vinya Wine & Market in Key Biscayne FL. When she's not working the floor, unpacking boxes, or writing, you can find her at the race track, betting on the underdogs.