Archaeological finds shed light on the history of winemaking in Champagne
When you think of the Champagne region, you think of… champagne. A symbol—if not a synonym—of celebration and luxury, this sparkling wine’s reputation is well established.
Vincent Bonhomme, University of Montpellier
site at "Place de la Libération" in Troyes, Aube. The plant remains were
preserved in water because they were retrieved from the bottom of a well. Grape seeds, pedicels, fragments of stems, and fragments of leaf blades can be identified.
Véronique Zech-Matterne, CC BY-SA
Inthe 17th century, its alleged inventor, the cellarer monk Dom Pérignon, is said to have told his fellow monks after his first tasting: “Come quickly, I am tasting the stars.” These famous bubbles are created through the “second fermentation,” that is, the controlled transformation of a still wine into a sparkling wine.
The modern history of champagne is well documented. But what did people drink in Champagne before it was invented? In a study published in *Scientific Reports*, a team of researchers—of which I am a member—draws on an exceptional collection of archaeological grape seeds to shed light on fifteen centuries of viticulture in the Champagne region, prior to the emergence of what we now call champagne.
15 centuries of glitches
The "Viticulture" research project, which includes our study—coordinated bythe Institute of Evolutionary Sciences in Montpellier (ISEM)—combines archaeoscientific approaches to better understand the history of French viticulture and winemaking, from their origins.
In this context, our team, which studies the biological and cultural histories of domesticated species, gained access to a collection of 572 grape seeds dating fromthe 1st tothe 15th century CE. Buried since that time, they were unearthed by fellow archaeologists during preventive archaeological surveys conducted prior to development projects in Reims and Troyes.
Tracing the history of the vineyards
To understand what we can learn from this, let’s remember that the grapevine is a domesticated species. In other words, humans largely control its reproduction, removing it from purely “natural” selection in order to improve it—more or less consciously—according to their own selection criteria.
From wolves to Yorkshire terriers, the diversity of forms resulting from domestication and subsequent selective breeding is striking. The form of organisms is a central focus of many disciplines, particularly in botany and archaeology.
At the intersection of these two fields, archaeobotany studies plant remains to better understand the history of the plants consumed by past societies. Morphology is often the only usable data, although ancient DNA can sometimes be analyzed.
Wild grapevine and cultivated grapevine
Mathematically, a shape is defined as that which remains "invariant under translation, rotation, and isotropic deformation." In other words, "all squares have the same shape, but not all triangles do."
Let’s take a closer look at the shape of grape seeds in modern vines. Those of wild vines—which are now endangered—have a rounded shape with a barely noticeable “beak.” Those of cultivated vines, on the other hand—grown for the table or for wine—are elongated, with a rather pronounced beak. And even within cultivated vines, the shape of the seeds varies by variety.
Sarah Ivorra
This variability, which is also evident in archaeological grape seeds, can be used to shed light on the history of viticulture. In the field of archaeobotany, differences can be observed between elongated seeds and rounder ones.
To measure the roundness, elongation, and, in short, the morphological characteristics of the seeds, we use an approach that combines mathematical and statistical methods.
Using seeds—whether modern or archaeological—we determine whether the vine that produced them was a wild vine or a domesticated variety and, in the latter case, its historical and geographical origins.
A digital signature for every glitch
In practical terms, how do we go about it?
Each archaeological artifact, which has been dated beforehand, is photographed individually from the front and in profile. The coordinates of their outlines are extracted, and these geometric shapes are converted into quantitative variables using appropriate mathematical transformations.
These shape variables have the advantage of capturing the full range of morphological information, without any preconceived notions about what we are looking for—not just height or weight. This is a major advantage because the differences are so subtle that we cannot know in advance which direction to look in.
The “actualist” approach and its limitations
Now that the archaeological seeds have been converted into digital morphological signatures, they are compared with those from collections of modern seeds, consisting of domestic and wild varieties collected from their natural habitats.
Within each archaeological assemblage (a collection of artifacts from the same period and site), we compare the populations of observed forms with those in our modern collections: this allows us to determine the proportions of wild grapevine to cultivated grapevine, as well as the geographical affinities (whether more southern or northern) of each seed for each site, and over time.
This approach is known as “presentist”: current diversity can shed light on that of the past. But be careful—it’s not enough on its own!
First, the passage of centuries may have altered the seed’s original form. Second, morphological similarity does not guarantee biological identity: an archaeological seed resembling that of a modern Pinot Noir does not necessarily prove they are related. Furthermore, the absence of archaeological data at a site during a given period does not necessarily mean that viticulture did not exist there. Finally, even when archaeological material is found, it is always in limited quantities, and we must make do with what we have. For example, our 15-century series includes 7 centuries with no data at all.
Nevertheless, the description of the plant’s form provides valuable insight into the history of domesticated plants.
Innovations in winemaking during the Gallo-Roman period
Let’s now apply this approach to our archaeological finds from Champagne. Based on the series of finds we have, we’ve been able to shed light on two major historical phases.
A significant portion of the records dates back to the Gallo-Roman period, that is, the first three centuries of our era. This is followed by a gap of seven centuries. Then comes another period spanning five centuries, from the year 1000 to the end of the Middle Ages.
The Gallo-Roman period featured both wild and cultivated grape varieties. Indeed, the use of wild grapevines is historically attested during this period in southern Gaul. Since the cultivated varieties used in the Champagne region at that time were of southern origin, it is possible that they were the same as those developed and used much further south during that era.
Studies using ancient DNA also reveal that the same genetic groups were present simultaneously in both the southern and northern parts of Gaul. The relatively mild climate of the time likely facilitated these population movements.
During this period, morphological diversity also increased, suggesting that cultivated varietal diversity was growing at the same time and indicating the emergence of viticultural experiments.
In the Middle Ages, the persistence of wild vines, a reflection of the climate and societies of the past
Let’s move on to the second historical period in question, which begins around the turn of the year 1000. Although grape varieties have been available for at least a millennium, wild-type seeds are still found in some of these blends—and in some cases even make up the majority.
To explain this, we hypothesize that wild populations were utilized during this period, which corresponds to the “medieval agricultural revolution,” a time marked by profound economic and societal changes.
Philippe Rollet
As in the early centuries of our era, domestic species also show affinities with southern regions. Here too, these findings correlate with the climate of that time, known as the “Medieval Climate Optimum”: a warming of a few tenths of a degree that affected Western Europe for several centuries. Such conditions appear to have played a decisive role in the history of grape varieties and wine in Champagne, as well as in other wine-growing regions.
This period was followed by the "Little Ice Age," marked by the first archaeological evidence of cold-adapted varieties characteristic of the Burgundy and Champagne regions, a little over two centuries before the invention of champagne.
These findings shed new light on the history of winemaking in Champagne and reveal a previously unsuspected evolution of grape varieties and its close ties to historical events and past climate changes.
Vincent Bonhomme, Researcher in evolutionary biology, University of Montpellier
This article is republished from The Conversation under a Creative Commons license. Readthe original article.