Archaeological finds shed light on the history of winemaking in Champagne
When you think of the Champagne region, you think of champagne. A symbol and synonym of celebration and luxury, this sparkling wine's reputation is well established.
Vincent Bonhomme, University of Montpellier
Residues of marc from the Troyes "Place de la Libération" site in Aube.
The plant remains were preserved saturated with water because they came from the bottom of a well. Grape seeds, pedicels, fragments of stems, and fragments of leaf blades can be seen.
Véronique Zech-Matterne, CC BY-SA
Inthe 17th century, its presumed 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 produced by the "prise de mousse," or secondary fermentation, which 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 its invention? In a study published in Scientific Reports, a team of researchers, including myself, draws on an exceptional series of archaeological finds to shed light on fifteen centuries of viticulture in the Champagne region before the advent of champagne.
15 centuries of glitches
The scientific project "viniculture, " 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 since their origins.
In this context, our team, which studies the biological and cultural histories of domesticated species, had access to a series of 572 grape seeds dating fromthe 1st tothe 15th century AD. Submerged since then, they were unearthed by fellow archaeologists during preventive archaeological research prior to development work in Reims and Troyes.
Tracing the history of the vineyards
To understand what we can learn from this, let us remember that the vine 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 selection is striking. The form of organisms is a central issue in many disciplines, particularly botany and archaeology.
At the intersection of these two fields, archaeobotany studies plant remains to better understand the history of plants consumed by societies in the past. Shape is often the only usable data, although ancient DNA can sometimes be exploited.
Wild grapevine and domestic grapevine
Mathematically, shape is what remains "invariant to translation, rotation, and isotropic deformation." In other words, "all squares have the same shape, but not all triangles."
Let's take a look at the shape of the seeds in today's vines. Those of the wild vine, now endangered, are rounded with a slightly pronounced "beak." Those of domestic vines, on the other hand, cultivated for the table or for wine, are elongated in shape, with a rather pronounced beak. And within domestic vines, the shape of the seeds of different varieties also differs.
Sarah Ivorra
This variability, which is also present in archaeological seeds, can be used to explore the history of viticulture. In the archaeobotanical record, there are differences between elongated seeds and rounder seeds.
To measure roundness, elongation, and, in short, the morphological characteristics of the seeds, we adopt an approach that is both mathematical and statistical.
From seeds—modern or archaeological—we determine whether the vine that produced them was a wild vine or a domestic 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 doing this?
Each archaeological artifact, previously dated, is photographed individually, from the front and in profile. The coordinates of their silhouettes are extracted and these geometries are converted into quantitative variables using appropriate mathematical transformations.
These shape variables have the advantage of capturing all morphological information, without any preconceptions about what we are looking for—not just height or weight. This is a major advantage because the differences are so subtle that we do not know in advance which direction to look.
The "actualist" approach and its limitations
Now that the archaeological seeds have been converted into digital morphological signatures, they are compared with those of modern seed collections, consisting of domestic and wild varieties taken from their habitat.
Within each archaeological assemblage (a collection from the same period and site), we compare the populations of forms observed with those in our modern collections. From this, we derive the proportions of wild vines to domestic vines, as well as the geographical affinities (more southern or northern) of each seed for each site, and over time.
This approach is known as "actualist": current diversity can shed light on that of the past. But beware, it is not enough!
Firstly, centuries of change may have altered the original shape of the seed. Secondly, morphological similarity does not guarantee biological identity: an archaeological seed similar to that of a modern Pinot Noir does not guarantee that they are related. Furthermore, the absence of archaeological data at a site during a given period does not necessarily mean that viticulture was not practiced there. Finally, even when archaeological material is found, it is always in limited quantities and we have to make do with what we have. For example, our series of 15 centuries includes 7 centuries with no data at all.
Nevertheless, the description of form provides powerful insight into the history of domesticated plants.
Wine-making innovation in the Gallo-Roman period
Let us now apply this approach to our archaeological finds in Champagne. Based on the series we have available, we have been able to shed light on two major historical phases.
A large part of the seeds date back to the Gallo-Roman period, i.e., the first three centuries of our era. This is followed by a gap of seven centuries. Then again, a period of five centuries from the year 1000 to the end of the Middle Ages.
The Gallo-Roman period saw the emergence of wild and domestic grape varieties. The use of wild vines is historically documented in southern Gaul during this period. The domestic varieties used in the Champagne region at the time were of southern origin, so it is possible that they were the same as those developed and used much further south during this period.
Studies using ancient DNA also reveal the simultaneous presence of the same genetic individuals in southern and northern Gaul. The climate at the time, which was relatively mild, undoubtedly encouraged these migratory movements.
During this period, morphological diversity also increased, suggesting that cultivated variety diversity progressed at the same time and implying the deployment of viticultural experiments.
In the Middle Ages, the persistence of wild vines, echoing the climate and societies of the past
Let's move on to the second historical period in question, which begins at the turn of the millennium. Although grape varieties have been available for at least a thousand years, wild-type seeds are still present, sometimes even predominating in some of these blends.
To explain this, we hypothesize that wild populations were used during this period, which corresponds to the "medieval agricultural revolution," marked by intense economic and societal changes.
Philippe Rollet
As in the early centuries of our era, domestic types also show southern affinities. Here too, these results correlate with the climate of the 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 seem to have played a decisive role in the history of grape varieties and Champagne wine, as well as in other wine-growing regions.
This period was followed by the "Little Ice Age," with the first archaeological appearances of types adapted to the cold and 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 winegrowing in Champagne and highlight a previously unsuspected varietal dynamic and its close links with historical events and past climate change.
Vincent Bonhomme, Researcher in evolutionary biology, University of Montpellier
This article is republished from The Conversation under a Creative Commons license. Readthe original article.