For centuries the maisons, caves and cellars of Champagne have been laboratories where experiments and innovations have created and refined the Traditional Method.  It is now highly specified but with many opportunities for each maker to create something distinctive and special.

Starting with a little history, we will look at the chemistry involved during the different stages of traditional method sparkling wine production, stressing that secondary fermentation is at the core of the process, creating both dissolved carbon dioxide and the characteristic aromas and flavors of the wine. A bottle of Champagne is a study in gases and liquids, and the bubbles are a topic in their own right. How the lees produce those characteristic aromas and flavors is a fascinating lesson in Biochemistry. We round off our presentation by talking about the final transition of the wine from bottle to glass.

John Manley came to Bristol to read Chemistry. This was followed by a PhD in Quantum Chemistry. During post-doctoral positions he transitioned to Artificial Intelligence in the early 1980s, working on Computer Speech Recognition. After 28 years at Hewlett-Packard’s European Research Labs, where his groups were involved in large-and massive-scale systems research, he retired as Laboratory Director of Cloud Computing. During this time he served on the Grid Advisory Group at CERN, the Science City Bristol Board, the EngineShed Advisory Board, the UoB Quantum Photonics Advisory Board, VentureFest Advisory Board and the DTi Grid Working Group. He was Chair of the International Advisory Board for the Smart Internet Lab. He was a Trustee of the University of Bristol for nine years, serving also as the Chair of the University IT Committee, Vice-Chair of the Audit Committee. He is a Visiting Professor at the University of the West of England, Bristol.

In 2020, Manley was Her Majesty’s High Sheriff of the County of City of Bristol – following this year he created AskingBristol, which is exploring how to “level-up” the Third Sector based on cities and regions. In a return to his roots in Chemistry, Manley has started a (long) series of talks on the Chemistry of Wine – hoping to reignite some interest in Chemistry for those who left it behind 1 to 80 years ago and at the same time explaining some of the endlessly fascinating and curious things about wine. Most explanations end up in the Chemistry, sometimes providing answers that are different from what we think we know. He and his wife, Jane, a Consultant Dermatologist, are co-owners of a vineyard in Vergisson producing Pouilly-Fuissé and Macon-Villages wines.

Timestamps

John Manley's Background (00:01) 

John shares his extensive career in chemistry, AI, and cloud computing, returning to wine chemistry. 

Overview of Champagne Research (00:01) 

John discusses the depth of champagne research and the misconceptions surrounding it. 

The Origins of Champagne (00:02) 

Explores the historical context of champagne's development and early observations on fermentation. 

Champagne's Appellation Rules (00:05) 

Details the regulations governing grape varieties used in champagne production. 

Introduction of New Grape Varieties (00:06) 

Discusses the approval of a fungus-resistant grape variety and its significance. 

Making Pink Champagne (00:08) 

Explains the two methods of producing rosé champagne and historical practices. 

Impact of Climate Change on Champagne (00:10) 

Analyzes how climate change affects grape ripening and harvest timing.   

Harvesting Grapes for Champagne (00:11) 

Describes the grape harvesting process and its timing influenced by climate change.   

Juice Extraction and Chapterisation (00:12) 

Covers the extraction of juice from grapes and the addition of sugar for fermentation. 

First Fermentation Process (00:14) 

Details the process of fermentation, producing base wine with specific alcohol content.

Malolactic Fermentation Explained (00:15) 

Clarifies the process of malolactic fermentation and its effects on wine acidity. 

Aging Base Wines (00:17) 

Discusses the aging process of base wines and the use of different containers. 

Blending Base Wines (00:20) 

Explains the assemblage process of blending different base wines for consistency.  

Fining and Filtering Wines (00:21) 

Describes the fining process to clarify wines, balancing clarity with flavour.   

Bottling for Secondary Fermentation (00:23) 

Covers the bottling process, including the addition of sugar and yeast for carbonation. 

Secondary Fermentation Process (00:24) 

Details the fermentation in bottles, producing carbon dioxide and raising alcohol content. 

Yeast Autolysis and Its Impact (00:26) 

Discussion on the role of dead yeast cells in champagne's mouthfeel and aroma.   

Riddling Process Explained (00:27) 

Overview of the riddling stage to remove dead yeast cells from champagne bottles. 

Disgorgement Techniques (00:29) 

Methods for removing dead yeast cells, including manual and mechanical processes. 

Liquid Dosage and Sugar Levels (00:30) 

Explanation of the liquid dosage added to champagne and its impact on sweetness. 

Corking Process and Equipment (00:32) 

Description of the equipment used to cork champagne bottles and its importance. 

Carbon Dioxide in Champagne (00:33) 

Introduction to carbon dioxide's role and properties in champagne. 

Understanding Acidity in Champagne (00:35) 

Comparison of acidity levels in champagne versus other beverages. 

Methods of Carbonation (00:36) 

Different methods for incorporating carbon dioxide into champagne. 

Physical Chemistry of Champagne (00:38) 

Champagne as a laboratory for studying gas and liquid interactions.   

Pressure and Carbon Dioxide Dynamics (00:39) 

Discussion on the relationship between pressure and dissolved carbon dioxide in champagne. 

Carbon Dioxide Release Upon Opening (00:41) 

How carbon dioxide escapes when a champagne bottle is opened. 

Bubbles in Champagne (00:43) 

Exploration of the number of bubbles in a glass of champagne and expert insights.   

Nucleation Points and Bubble Formation (00:47) 

Investigation of where bubbles form in champagne and factors affecting it. 

Aromas and Flavors in Champagne (00:50) 

Overview of the various aromas and flavors derived from different stages of champagne production.  

Chemicals in Wine (00:51) 

Discussion on the chemical compounds responsible for specific flavors in wine. 

Yeast and Aging on Lees (00:52) 

Explanation of how yeast breakdown contributes to aroma and taste in champagne. 

Synthesis of Flavour Compounds (00:53) 

Overview of the synthetic pathways for flavor compounds in champagne. 

Opening Champagne Bottles (00:55) 

Details on the pressure in champagne bottles and safe opening methods. 

Health Benefits of Champagne (00:58) 

Mention of potential health benefits associated with moderate champagne consumption. 

Allergens in Wine Production (01:00) 

Discussion on allergens in wine and labeling practices for consumer safety. 

Researching Champagne Varieties (01:02) 

Insights on the challenges of finding comprehensive information on champagne production.  

Freezing Point of Brine (01:03) 

Exploration of whether adding salts can lower the freezing point of brine. 

Myths About Champagne (01:05) 

Debunking myths related to champagne storage and serving techniques. 

Safety When Opening Champagne (01:07) 

Advice on whether to remove the cage from the cork for safety reasons.