10 June 2024

Stems revisited

By Sara Guiducci, Head of Private Client Sales

Trends come and go in winemaking, usually accompanied by new winemaking jargon. In the last twenty years we have seen a focus on elegance and freshness in wine, accompanied by a huge increase in the use of stems, not just in Burgundy but around the world. Terminology is broad and the addition of stems to wine can be referred to as stems, whole-bunch, or whole-cluster and are wholly interchangeable.  

A bunch of grapes is made up of a thick middle stem called the rachis (which at the top connects to the vine shoot), and from these spread tiny branches called peduncles, which carry the individual grape berries. The connecting twig between grape and peduncle is called the pedicel. This twig represents between 2-5% of the weight of an actual berry. The structure starts out as green material that is capable of photosynthesis that lignifies to a wooden structure and the ripeness of this structure is a key component to the effect stems have on the final wine.  

While early wine was always made with either pressing or macerating the stems (removing the stems by hand is labour-intensive and time-consuming thus expensive), the invention of mechanical destemming devices, such as the Rebler at the beginning of the 19th century, changed the viticultural landscape. The addition of stems became an expensive, stylistic choice. Most classical European wine regions are traditionally located on the edge of where the varieties are able to ripen. As a result, producers must have been overjoyed with the invention of the mechanical de-stemmer as the stems bring acidity and tannins to the wines, which can result in rusticity to the wines, especially in cool vintages.  

Almost all top echelon producers historically famed for using stems are located in Burgundy (DRC, Dujac and Ponsot). So, in more recent times, stems have been closely linked to Burgundy and by extension Pinot Noir. Perhaps this is not surprising.  Pinot Noir’s thin skin and lower skin-to seed tannin ratio leads to lower tannin and anthocyanin levels, which means that the additional tannins from stems can add structure to the wines (and perhaps more importantly, wouldn’t necessarily make the wines overtly tannic thereby allowing for easier experimentation than varieties which typically have high tannin levels such as Cabernet-Sauvignon).  

Jasper Morris MW has previously suggested that Burgundy’s interest in destemming had been linked to its hero, Henri Jayer, who argued that stems compromised Burgundy’s potential to make great wines and was one of the most influential proponents of destemming and it is true that very few producers continued whole-bunch practice. Fast forward a few years and after Jayer’s death more producers are experimenting with stems. Why? Perhaps because iconic producers such as DRC and Domaine Dujac successfully held steadfast with their use of stems. Perhaps because global warming allowed for riper stems, reducing the chances of rough tannin structure. Perhaps because it increases freshness and elegance in a post Parker world. Perhaps because better vineyard husbandry gives grapes and vines a healthier, riper profile.  Jeremy Seysses at Domaine Dujac is a great advocate of stems and claims that for him it adds greater complexity and silkier tannins, which in cooler vintages rounds the acidity and in riper vintages adds freshness.  

In real terms and when used correctly, stems lower the real acidity of the wine due to increased potassium in the bunches, but give a sense of freshness due to the tang of green sappiness. It changes the textural experience by increasing the glycerol content increasing the sense of texture in the mouth. It also affects the aromatic profile of the wine and when done badly it dulls the palate adding manure aromas in youth (though I have seen at times that these wines transform with age to become beautifully elegant), but when done well, stems add fragrance, a heady perfume and create silkier tannins. Though occasionally this could override the sense of terroir, in the hands of great producers and from great terroir this gives an added layer of complexity and sensual structure that is beguiling, which is after all, the essence of Burgundy. 

It comes as no surprise therefore that we have seen a rise of producers using stems in the past two decades. And of course this is not confined to Burgundy. While Domaine Dujac and DRC were forerunners and top echelon proponents of stem, it has been fascinating to see how this has influenced Pinot Noir producers around the world. Steve Doener, winemaker at Cristom in Oregon visited Jeremy Seysses early in his career, influencing him to use high levels of stem at Cristom, which they call the hallmark of their style. Steve describes the effect of stems (or whole cluster) as follows ‘The effects of whole clusters are wide ranging, reflective of the vineyard and the vintage and are at the heart of the Cristom winemaking style. Whole clusters bring another level of complexity to the aromatics and an additional dimension of tannin to the palate and help the wines to better express the identity of their terroirs. Whole cluster fermentations can produce a dynamic and expansive range of spicy aromatics like crushed pepper, cloves, cardamom and cinnamon, herbaceous notes of tobacco and black tea, and earthy aromas reminiscent of the forest floor’ 

From Burgundy and Pinot Noir, experimentation with Syrah and stems was successful and though not as widespread as with Pinot Noir, many producers in the Northern Rhône (and abroad) adopted the practice. However, two decades ago it seemed unlikely that stems would ever be used on high tannin varieties like Cabernet Sauvignon and yet a series of warmer vintages and in a post-Parker world, a desire for elegance and freshness has led to experimentation with tannins in Bordeaux. Many were skeptical to start with, but Ch. Carmes Haut Brion embraced whole bunch with staggering success or in the words of Vinous critic Antonio Galloni  ‘Les Carmes has been one of Bordeaux’s stars over the last few years’.