Reverse Engineering of Neolithic Wines (or The Coolest Job in the World!)



Chateau Jiahu: A blast from the past

 I do protein engineering for a major pharmaceutical company and I love my job.  I get to work on interesting scientific questions, use the coolest technology ever, and at the end of it all, contribute to developing medicines that might help people.  What’s not to love?  Then, sometimes, I get job-envy.  That happened last week when I read about Patrick McGovern.  He leads the Biomolecular Archaeology lab at the U. Penn. Museum of Archaeology and Anthropology (link) and if he ever wants to trade jobs for a day, I’m game. (Unless it’s Wednesday, because that’s the day we get free food.) He’s been called “the Indiana Jones of ancient ales, wines and extreme beverages”.  Yeah, apparently they had Jager-bombs back then. This guy’s research involves chemistry, genetics, archeology, anthropology, and wine/beer making.  Sometimes wine was also used for healing, and he also tries to determine the pharmacological significance of these chemicals, such as their antibacterial or anti-cancer properties (but I’ll save that for another post).



Malvidin: A wine fossil?



How does he do all this?  Vessels are dug out of archaeological sites around the world (Egypt, Iran, etc) and although they are empty, there is still residue on the sides, like grape juice stains.  These residues have specific chemical signatures that can be detected (usually by mass spectrometry) even after thousands of years. Remember the magic stuff I talked about in the winemaking post (link)?  The presence of these compounds provides strong evidence for fermentation.  However, most of these exist in very small quantities, making them difficult to detect in ancient residue.  The most abundant chemicals in wine (such as tartaric acid) are present in grapes and are not necessarily a marker for fermentation (a jar of wine would look the same as a jar of grape juice).  However, a recent study (abstract) has demonstrated that malvidin or syringic acid may be better markers for evidence of grape fermentation. Malvidin is the chemical that gives red wine its color, but more importantly, it is one of those magic chemicals that polymerizes over time.  In the lab, malvidin polymers can be broken into syringic acid (which is easy to detect) and large amounts of syringic acid can suggest the pot once held fermented wine.  The identification of other compounds or even the sequencing of ancient grape DNA can provide further evidence of wine or beer production.

Although this information provides important clues for studying the rise and fall of ancient civilizations, there is another, much more interesting consequence: Reverse engineering. By identifying the components and byproducts of ancient wines and beer, it becomes possible to try and reproduce today what was made thousands of years ago. McGovern has worked with Dogfish Head Brewery to make modern versions of ancient ales. One example is Chateau Jiahu (link), a fermented beverage of rice, honey and fruit that was made based on the chemical residue found in pottery jars from a Neolithic village known as Jiahu. Chateau Jiahu is an exciting opportunity to taste a drink that has been extinct for over 9000 years! Archeology, biochemistry, and beer… yeah, that’s a cool job.