Thousands of books about wine are written each year. I’m sure many of them are excellent, but this month brings a new book entitled, A Natural History of Wine, that is quite different from all of the rest. This is a book about what science teaches us about wine and what wine teaches about science. It was not written by or for wine professionals. It’s written by scientists who love wine, for wine-lovers who love science. After all, “Wine is stardust.”(One of the chapter titles!)
Ian Tattersall and Rob DeSalle, both curators at the American Museum of Natural History, have dozens of books to their credit and have collaborated on such diverse topics as race, human origins, and the brain. Tattersall is a preeminent anthropologist and seasoned oenophile, while DeSalle is a leading entomologist/microbiologist and an amateur brewer of tasty libations. Together, they focus their scrutinizing scientific perspective on the total wine experience, from soup to nuts. Or roots to skins, as it were.
“We started talking about wine and we realized that wine had a lot to tell us about science and science had a lot to tell us about the enjoyment of wine.”
It turns out that there is no end to the topics that one becomes educated about when exploring the subject of wine. From biochemistry to archaeology, botany to genomics, and microbiology to evolution, the wine-making process is simply drenched in fascinating science.
And of course history. The book begins with a look at how wine making first flourished in the ancient and prehistorical world. After all, humans have been making wine for thousands and thousands of years. Readers learn about the musty caves in Europe and Asia in which prehistoric wine-makers tinkered with the intoxicating fermenting fruit.
“Once people were settled down, one of the first things they did was to start fermenting grapes”
Then, the book explores how various civilizations put their own unique stamp on wine-making and, in turn, how wine became integral to those cultures. While reading these first two chapters, it struck me that refined wine making was something of a “badge” of civilization. In both the East and the West, the dainty wine-sipping of cultured societies replaced the crudity of the barbarian, who simply slugged down raw fermenting grape mash (or “must,” as grape mash is properly called) or, even worse, had no knowledge of wine at all. (gasp!) Most uncivilized.
Truth be told, humans and our ancestors have been drinking the fruit of the vine for not just thousands, but millions of years. As explained in chapters 2 and 10, humans share the enzymes allowing us to process alcohol with other great apes. This allowed our ancestors to consume certain over-ripened fruits (in which fermentation had begun) which would have otherwise been toxic due to the alcohol byproduct. Furthermore, Tattersall and DeSalle recount experiments which show that alcohol content, as measure by alcohol vapor near the fruit, is a better indicator of sugar content than is color. (Color being what is normally thought of as the best indicator of ripeness and thus, sweetness.)
“In West Africa… local chimpanzees have developed a predilection for the spontaneously fermenting sap of the raffia palm and they go after it quite eagerly and they scoop it up using sponges made of leaves and what not.”
That is but one example of how the perspective of science is brought to bear on the subject of wine in this beautifully illustrated book. I’m sure hundreds of science geeks will regale their friends and family with the stories of how fermenting fruit nourished the bodies and the minds of our evolving ancestors in the African savannah.
However, as Tattersall and DeSalle write:
Naturally occurring sources of alcohol hardly fill the bill, which is why it is more likely that, from the time when they first gained the intellectual and technological wherewithal to figure out how to do it, humans have been devoted to the artificial production of alcoholic beverages.
So we have.
Each chapter begins with a short bit about a specific wine chosen to represent the content of that chapter. The authors describe their impression of the wine and the underlying science that makes that wine special. The descriptions are lush and vivid, so much so that you can almost taste the wine yourself, a perception further amplified by the chapter that follows.
“Wine is not a single product made by a single process. The fascination of wine [comes from] its variety.”
Being curators at the greatest natural history museum in the world, Tattersall and DeSalle also discuss the many lessons that phylogeny and systematics can teach us about wine as well. The genetic legacy and shared ancestry of the various species and strains of grapes are explored, which provides satisfying insights into the flavors and other properties of each wine grape variety. This chapter (along with every other I suppose) is really enhanced by having a few varieties of wine handy. The various flavors, colors, and textures really come alive when you begin to understanding something about their history.
In addition, we get a light lesson in the basics of botany and horticulture as we learn about grafting, root stocks, plant parasites, and soil conditions. Although most wine professionals will know this well, few others are probably aware that the entirety of French wine-making was nearly destroyed by the Great Wine Blight of the mid-19th century. Only the transplant of foreign root stocks, which had natural resistance to the parasitic aphids, prevented the total decimation of the local grape population. It might be thought ironic that the savior root stocks came from the New World, the same place from which the aphid pests probably came, but Tattersall and DeSalle are quick to point out that this is the expected result. The American root stocks had evolved natural resistance to the Phyloxera aphids by necessity. Like with immunity, only the exposed develop resistance.
Not to be forgotten are the yeasts. After all, they are both the driver and the engine of fermentation, with grape juice being merely the fuel. The various species of yeast and their unique contributions are explored in chapter 5, after of course, we are all brought up to speed about what fermentation is in chapter 3. After all, the making of wine is a lesson in chemistry. Like brewers, nearly all wine-makers have advanced education in biochemstry and/or microbiology.
“You can think of fermenting wine as a living culture and any time you have a living culture, you have interactions, and those interactions are important for the quality of the end product.”
I sat down with Tattersall and DeSalle to discuss the book and, not surprisingly, gained fascinating insights on how this project came to be.
Nathan Lents: So who did you write this book for?
Ian Tattersall: Anybody who likes wine and anybody who likes science. I think this book is as much science as seen through the lens of wine as it is wine seen through the lens of science. Rob and I have done many books together in the past and we were usually drinking wine and we realized that, while talking about other things, wine keeps coming back into the conversation. Everybody that drinks a decent wine seems to have this need to talk about it and think about it because there is a lot more going on in a glass of wine than there is in your average drink. So that’s really what happened. We started talking about wine and we realized that wine had a lot to tell us about science and science had a lot to tell us about the enjoyment of wine.
NHL: It was interesting to me because I was only vaguely aware of all the science of wine-making, but I am a whisky drinker and I think I know a little bit about whisky and it seems to me that you could write the same sort of book about the science of whisky.
IT: Yeah, you could, because what you have is an incredible amount of variety and subtlety, in whisky and in wine, and that’s what’s amazing because no two wines are alike and no two whiskeys are alike. You just have this great variety to entertain your palate and entertain your mind as well.
NHL: How was wine-making affect the development of skills and technology in our species?
IT: Well I think that wine-making technology was one of the very earliest technologies that was developed by sedentary peoples. We have a long history of development of technology in human evolution, two and half million years at least of technological development, but once people were settled down, one of the first things they did was to start fermenting grapes. So, you’ve got a huge amount of science even covered there. These guys were intuitive scientists. They weren’t scientists in a self-conscious sort of way, but they had to select the grapes, they had to breed them, they had to domesticate them, and then they had to convert them into wine and then they had to store that wine and make sure that it didn’t spoil. And that’s one technology after another. Once you’re on that path, you have to continue developing those technologies and I think that the making of wine was one of the main components of this very early burst of technological development that you’ve got once people had become sedentary and started to domesticate plants and animals.
NHL: Had some of that knowledge been with them even before they settled down? And then settling down just made it easier?
IT: Well I think that even before humans started thinking in the way that we think, which was at least 50,000 years ago, maybe 100,000, people have always been keen observers of nature and the various things that are happening in nature and I’m sure that they knew about spontaneous fermentation. What I don’t know is if any hunters or gatherers ever contrived to use, I don’t know, a goat’s bladder or something as a fermentation vessel. That’s anybody’s guess.
NHL: Because those kinds of artifacts would never have been preserved…
IT: Right, we just wouldn’t know about it.
NHL: You mentioned the debate [among anthropologists] about whether the domestication of cereals was driven more by an interest in making bread or an interest in making beer. Do you have an opinion about that?
IT: Well, it’s a strange thing because wine is quite a bit easier to make than beer is, but what we have is a very good record of the early grinding of cereals. In fact, the earliest evidence indicates that this was happening way, way back, long before the adoption of sedentary lifestyle, so people have been making bread since long before they had ceramic containers to make a liquid beverage. So I would suspect that bread came first, but once you have bread, you certainly have beer. They go hand-in-hand.
NHL: And do you wonder if maybe we don’t see wine production nearly as far back simply because the implements and artifacts used to do it just didn’t survive? As you say, wine is much easier to make than bread or beer. I mean, you can even sort of stumble upon wine any time in your in a lush tropical forest.
IT: One of the really difficult things is this question of definition, where beer ends and wine starts. Nine thousand years ago in China, you have chemical traces in ceramic vessels of what you can call a beer, it’s a rice-based beer, but they throw all sorts of other stuff in there as well, including grapes. But they are very much in China a rice-based culture. There is no really good evidence of grape domestication until much later. The earliest traces of wine making that we have in the West is from a place in Northern Iran, and they’re about 7,000 years old. So the earliest wine traces are actually a bit younger than the first beer traces even though beer is much more complicated thing in the sense that you have to convert all the starches into sugars before you begin the process of making your beverage.
NHL: So what about the evolution of our culture and the way we build our societies? How much do you think wine-making affected that?
IT: Well, wine-making obviously has had a very profound affect on societies but it’s not an easy effect to put your finger on except in the context of ritualized behaviors like religion and so on. In the Western world, we happen to have a set of religions that is pretty wine-friendly, the Old Testament, for example.
NHL: and even before that…
IT: Yes, even before that, you have plenty of positive references to wine and the grape, but alcohol goes both ways. Wine can be a wonderful adjunct to life, it can ease social tensions, it can make life bearable in many ways, but it can also be abused and so there is, on the one hand, the tendency to enjoy it, but on the other hand, it can get out of control. Those two things co-exist rather uneasily.
NHL: One thing that struck me while I was reading the book is that I was getting a little bit of a history of civilization, especially in the West, and it seemed like wine-making was a sort of badge of civilized life. And this unfolded in Europe, the near East, the far East. Do you see it as more than just a sign of civilization, but perhaps possibly a contributor?
IT: It certainly helped to produce identity. The Greeks were not the only ones in the ancient world to make wine, but it was in the way that they drank wine that they distinguished themselves. The Greeks watered their wine and drank it in the context of the symposion and so on, where as the barabaroi would just quaff the stuff whole and undiluted. So, it was powerful how the Greeks drank wine because it helped create their identity.
For the Egyptians, wine was very important, even as far back as pre-dynastic burial. In Midos (bibos?), I think it is, in the pre-dynastic era, before the unification Egypt, there was a ruler that was buried with 3,000 liters of wine, which had been brought all the way from the Levant and included the best wine in the world at that time. So wine was obviously very, very important. Some of the importance seems to be in the context of medicine. The products of fermentation are useful in dissolving some of the natural chemicals that can be found in nature and certainly some of the burial wines that you find in Egypt from 5,000 years ago had medicinal compounds dissolved in it. It makes you wonder what kind of afterlife he thought he was going to have, filled with parasites that would need to be treated and so forth.
NHL: It’s no surprise that humans have shaped the grape over the years of domestication, but do you think the drinking of alcoholic beverages has shaped us also?
IT: Well, all mammals have a certain degree of alcohol tolerance, though nowhere near to the degree that humans have, and the latest evidence seems to support that the mutation that allows humans to consume such large quantities is shared with other apes, meaning that the common ancestor had it as well. You can see what an enormous advantage this was for our ancestors because naturally occurring fermentation occurs where the sugar is. And we see today that all of the fruit-eating primates are attracted to ripe and overripe fruit probably for this reason.
NHL: So the spontaneous mutant that could tolerate larger amounts of alcohol would have a big advantage.
IT: Yeah, accidentally, but the other primates that have this mutation today, that would be the great apes, don’t seem to be big drinkers. They don’t seem to specifically seek out fermenting fruit. There is a local exception in West Africa where the local chimpanzees have developed a predilection for the spontaneously fermenting sap of the raffia palm and they go after it quite eagerly and they scoop it up using sponges made of leaves and what not. It’s only just been documented but it’s interesting because the Raffia Palm is native to Madagascar and cannot have been in West African for more than a few centuries. This is something that they’ve recently discovered and they drink it and they like it.
NHL: So this is a case of cultural transmission?
IT: It’s exactly that, yeah, in just the same way that they teach and learn to hunt for termites or smash palm nuts using an anvil and that kind of thing.
NHL: What are your thoughts on the various health benefits that are attributed to drinking wine?
IT: This is something we tried to avoid in this book because it’s highly political and there are a lot of opinions out there, and also a lot of the studies are not as rigorous as you might want them to be. But, what has always struck me is that the kind of answer you get to this question from a physician seems to depend on what kind of physician it is. Cardiologists love alcohol! But hepatologists hate it. Alcohol can obviously have very destructive effects on the body, especially in large quantities, but in smaller quantities it seems to be good for most systems.
NHL: So you support the notion of a glass or wine or two a day being better than none?
IT: That does seem to be the case, yeah. It used to be that red wine was touted more than white white, but the latest I’ve seen is that white wine is not such a bad idea either.
(At this point, Rob DeSalle enters the interview by phone.)
NHL: I think most people aren’t surprised to learn that different varieties of grapes are used to make different varieties of wine, but what about the yeast? Are there are different species or strains and what effect do they have?
Rob DeSalle: Well, just like geneticists have looked at the different strains of grapes that make up wine, they have also looked at the different strains of fungi, the yeast that are part of the fermentation process. There is one main species that does it, Saccharomyces cerevisiae, and a couple others that are involved, so while the varieties of grapes that are used to make wine is really broad, the variety of yeast is quite narrow traditionally. But, recently, people are beginning to experiment more and more with the fermentation process, the pace of fermentation, the kind of yeast, even the kinds of bacteria that also kind of co-ferment the product.
NHL: Are there different strains of Sac [Saccharomyces cerevisiae] that have a big difference on the process?
RD: There are, but it looks like what’s happened is that different wine-makers have maintained their strains as isolates for generations and those are used pretty consistently from batch to batch, so even though it is a smaller catalog of diversity compared to the grapes, it seems likely that each unique strain contributes to the unique identity of the wine.
But it’s important to remember that the yeast strain that the wine-makers add intentionally is not alone. There are yeasts that come from the grapes that are different and there’s bacteria as well.
NHL: So then, it seems like fermentation is a complex mix of biotic and abiotic factors all interacting like an ecosystem. Do you see fermentation as an ecosystem?
RD: Oh absolutely. We discuss the concept of [fermentation] as mostly caused by ecosystem interactions. There was a really great study that was done a couple years ago of the microbiome, so to speak, of grapes from Napa and Sonoma and the Central Valley compared to other ecological contexts as well as from different kinds of grapes, Chardonnay versus Pinot, and you can actually look at what kind of microbes are growing on the grapes and soil in which the grapes grow and those are influencing the grapes in a big way. So even before you start to ferment the grapes, you have all of these interesting ecological interactions that are going on. Then, as you pointed out, once you get the fermentation process going, there are all kinds of microbes that are doing things in the [must] and this is really an ecological context. You can think of fermenting wine as a living culture and any time you have a living culture, you have interactions, and those interactions are interesting and important for the quality of the end product.
The thing that you want to do with wine is that you want to control those interactions. You don’t want a bacteria to come in and take over and take over at the expense of the yeast because the bacteria are going to ferment and produce acetic acid, whereas the fungi, the yeast, are going to produce alcohol, and you want a nice balance between those.
NHL: So how has your appreciation of wine been enhanced by the research and writing of this book?
IT: We had to drink quite a lot of wine in the course of writing this book and that really propelled us to widen our passion area for wines, as it were. We drank a lot of wines that we wouldn’t otherwise have drunk and I’ve gotten a new appreciation for the sheer varieties of wine that are out there. We intentionally tasted a lot of unusual wines because we wanted to see what the limits were in the wine world, and it’s been very instructive.
RD: Well I am more of a beer drinker myself and I even make my own beer, so I learned orders of magnitude more about wine than Ian did because I was starting from so much farther down the learning curve. But as Ian pointed out, these really wonderful wines that we drank for the book really taught me a lot about the variety of wine that is out there.
IT: I’d say you worked really hard.
RD: [laughs] Yes, it was hard work.
NHL: So what is your advice for others about how they can get more out of their wine experience by understanding more about it natural history?
IT: Well you have a very complex wine market out there. And you have very dynamic wines and you have low sulfite wines and you have all these incredibly diverse products. Wine is not a single product that is made by a single process. The fascination of wine depends on its variety. That variety comes from varying the process of producing wine at all levels, from growing different strains, different vineyards, different exposures, latitudes, geography, all the way to various things you can do in the winery to make a different style. There are a lot of technological interventions that can make wines of different depths, different alcohol content, nowadays. Knowing this gives you a starting point when you’re trying to negotiate your way around this dizzying marketplace of wine. You have to ask yourself, ‘well, where am I going to start?’
RD: My major advice is don’t trust your judgment until you’ve actually tasted the wine because there’s a lot of things that can trick you before you even let your senses experience the wine. There are even neuro-economic kinds of tricks. For instance, it is well known that the more difficult a wine is to pronounce, the more likely someone is to prefer it. There are effects of the label color and design, and things like that and so for people who do not know a lot about wine, they will choose one based on the label and the price. My advice to anyone that wants to drink wine seriously is to simply trust your sense, your taste, your smell, your sight. Otherwise you can get tricked and wine sellers know those tricks. Just taste it and enjoy it. When I was tasting wines with Ian, I never let him tell me how much the bottle cost, because I knew that it would influence my response to it.
IT: And this is true not just of wine. There is a great deal known about how the packaging and other things affect our perception of food, so this is telling us something larger about how the mind puts all of this information together into our experience. I just think wine is the coolest example of how your brain does this mysterious work.
(Ed: As if the experience of this interview wasn’t enchanting enough, toward the end of the interview, I received a phone call with some good news. Ever charming, Tattersall promptly fetched a special wine for the occasion and we toasted together. This rather magical moment is fully recounted here.)