The whole-bunch question
To de-stem or not to de-stem? Our Burgundy Buyer, Adam Bruntlett, takes a deep dive into the surprisingly complex world of whole-bunch fermentation, considering the pros, the cons and what it means for the wine in the glass
We’re tasting the 2021 vintage with David Croix in his cellar in Beaune when a familiar subject rears its head: “In the past, people always used to ask about the percentage of new oak in a wine. Now, it’s the percentage of whole-bunch.” The use of whole bunches is a hot topic of discussion for red wines. But what does whole-bunch mean, and why does it matter?
WHOLE BUNCHES AND DE-STEMMING
Historically, making red wines was a simple process in Burgundy: grapes were harvested by hand, and the whole bunches were put into open-top wooden vats for fermentation. The wines were often light, pale in colour and a little “green” in ﬂavour. Separating the stems from the grapes by hand was possible but did not become a serious option until the development of mechanical de-stemming machines in the 20th century.
Towards the end of that century, aided by advances in technology, the winemaking process became easier to control. De- stemming the fruit became more popular, along with the use of more new oak, commercial yeasts and enzymes and other practices like cold maceration. The wines became richer, more deeply coloured and more marked by oak. A decade or so ago, the pendulum started to swing back; many growers now want to make wines in what they deem a lighter, more natural style. At the same time, warmer growing seasons mean that using stems doesn’t necessarily lead to thin, green wines.
"Whole bunches take up more space than de-stemmed fruit, so in a generous vintage the whole crop might be de-stemmed"
Some growers are firmly in one camp or the other: entirely de-stemming or using 100% whole bunches every year, no matter what. This tends to be based on experience and personal taste. François Bitouzet always de-stems; he feels he simply doesn’t have the “touch” to use whole bunches. In contrast, Jean-Pierre Guyon was once an ardent de-stemmer; he now uses exclusively whole bunches every year for every wine, from his basic Bourgogne to his Echezeaux Grand Cru. Many growers vary their approach one way or the other depending on a range of variables.
FOR AND AGAINST
Keeping the bunches whole has two main beneﬁts. First, it allows the berries to stay intact, therefore enabling carbonic maceration to take place. This is when the juice ferments inside the grape, producing light and fruity wines with ﬂavour and colour but relatively little tannin. Second, the stems also have an impact on the final wine. They affect the wine’s texture, imparting tannins that are different in proﬁle to those extracted from the skin and pips; this can add a welcome sense of freshness in warm years. Jean-Pierre Guyon believes the stems contain mineral salts which give his wines a saline character. Stems also give hallmark ﬂavours such as ﬂoral notes, crushed strawberry, sweet spice and some herbaceous notes (though these aromas could also come from carbonic maceration).
Opponents point to the fact that including stems (which are rich in potassium) makes the wine taste softer and lower in acidity. On a chemical level, the wine is less stable and more susceptible to microbial and bacterial spoilage. Organoleptically, it can make the wine taste sweeter on the mid-palate, and the pronounced ﬂavours and aromas associated with whole bunches can mask the identity of the vineyard – giving whole-bunch wines a slightly homogenous feel, particularly in youth. While some ﬂavours of the process are pleasant, it is a matter of taste and preference, and the inclusion of stems can also lead to green, earthy ﬂavours and dry tannins.
NOT BLACK AND WHITE
As with any winemaking question, the choice is not binary. The ﬁrst de-stemming machines were aggressive, crushing the berries in the process. Modern versions are so gentle as to leave the individual grapes almost entirely intact, reminiscent of caviar in the vat. Etienne Grivot – an avowed de-stemmer – believes this gives the ﬂoral ﬂavours and aromas of stems without any green character.
Additionally, the proportion of stems can be varied according to the quality of the fruit, the vineyard or the vintage. Often this is deﬁned by the practical consideration of how much space there is in the tank. Whole bunches take up more space than de-stemmed fruit, so in a generous vintage the whole crop might be de-stemmed. In a small year, it may be beneﬁcial to use more whole bunches to ﬁll the tank and make it easier to work the vat.
Even how the whole bunches are used is widely debated. Many producers, such as Domaine de la Vougeraie, like to layer de-stemmed grapes and whole bunches in the tank like a millefeuille. A small number will put whole bunches at the bottom to help the juice drain, with de-stemmed fruit on top.
"Whole-bunch can undoubtedly bring a different array of flavours and aromas to wines"
There is yet further nuance in what constitutes a whole bunch. Thibault Liger-Belair, Domaine de la Vougeraie, Arnaud Mortet and Jean-Pierre Guyon, among others, painstakingly remove the rachis (the central trunk) of the bunch, leaving mini bunches with a few grapes on each peduncle (the branches which join a few grapes each to the main trunk). Proponents argue this gives a more subtle whole-bunch character to the wines and eliminates some of the herbaceous and dry notes often associated with whole bunches.
But what – besides dogmatic attachments to one or the other – makes a grower decide which approach to take?
The vintage conditions are perhaps the biggest factor on whether to de-stem, or what proportion of whole bunches to use. In warmer years, when the fruit is riper, the tendency is to use more stems to give the wine more freshness. However, others argue that the reduced acidity from using stems makes the wines heavier; they take the alternative approach. In cooler years like 2021, many will dial back the proportion of whole bunches as the stems may overpower the more delicate fruit ﬂavours and impart too much greenness. Some say this is because the stems themselves are less ripe. Carel Voorhuis at Camille Giroud believes it is because the skins and grapes are less ripe, and the stems therefore have a more dominant effect.
Vine age is another factor. Some growers prefer to de-stem young-vine fruit and keep the fruit from old vines intact, arguing that the small bunches of tiny, concentrated berries are more suited to the practice. Others argue that the shape and size of the bunch is important. They say that loose bunches – where the stems are exposed to sunlight and can therefore “ripen” or lignify – are best for whole-bunch fermentation.
Others believe the natural tendency towards rusticity in the vineyard plays a larger role in deciding whether to de-stem. But again, there is some debate. Most growers would de-stem grapes from “rustic” terroirs as the stem tannins will reinforce the natural structure of the wines. Others feel that the mid-palate sweetness imparted by the process can be beneﬁcial in softening some of the edges. Experience plays a part, and some vineyards suit stems while others don’t.
The soil composition of the vineyards is another consideration. Benjamin Leroux never includes any whole bunches for his Volnay Premier Cru Les Mitans, for example. This parcel was generously fed with chemical fertilisers in the past; there is signiﬁcant residual potassium in the soil and the pH of the wines is often relatively high. Any additional potassium leaching from stems would push the pH up to a level which could allow for microbial spoilage such as Brettanomyces. A higher pH can also lead to more noticeable volatile acidity, which can often lend a nail-varnish aroma to the wine. With pH levels generally rising due to warmer weather, there may be less incentive to use whole bunches in the future.
THE BIGGER PICTURE
What does this mean for the use of whole bunches? Like many trends, my inclination is that some vignerons do it because it’s fashionable. Like the once-ubiquitous new oak, its use may fall away somewhat. The whole-bunch question will continue to rumble on. Whole-bunch can undoubtedly bring a different array of ﬂavours and aromas to wines. How those wines are received tends to be quite divisive, with passionate views on either side of the argument.
Personally, I believe that the use of whole bunches tends to mark wines from “lesser” sites more heavily, often leaving a pleasant wine which tastes perhaps more of the process than the vineyard. As you climb the quality hierarchy, the strength and personality of the vineyard shines through more clearly. Then, the whole-bunch element serves to add complexity in the background as opposed to dominating proceedings.
Typically, the whole-bunch character tends to be prominent in youth and become less pronounced as wines age. When deciding whether to choose wines made with or without stems, it is important to understand that results vary across domaines, even if the percentages used may be similar. As ever in Burgundy, the raw ﬁgures only tell a fraction of the story. The best advice is to sample wines without preconceptions and let your palate decide.