Written | Nicola Jones
Translated | Hu Tangyan
Proofreading | Yu Mingqian
In the center of France's wine country there is a laboratory where researchers have carefully placed a super-high-speed camera. Like other scientists, they are dedicated to exploring the mysteries of the universe, trying to describe the physical world in the language of mathematics, physics, and chemistry. They studied bubbles in champagne.
Gerald Lig Bel Air is a chemical physicist who probably knows more about champagne bubbles than anyone else in the world. He is the head of the "Champagne and Bubbles" group of eights at reims University. Since he wrote his doctoral dissertation in 2001, he has been working on how champagne bubbles inside and on glasses. He has authored more than 100 technical papers on the subject, including an in-depth study of Champagne and sparkling wine published in the Annual Review of Analytical Chemistry in 2021, and a best-selling book, Open The Bottle: Demystifying the Scientific Mysteries of Champagne.
"When I was young, I loved blowing soap bubbles and observing them," he recalls. This fascination has always existed, and he has made a series of practical actions: there may be many reasons to be interested in bubbles, far more than sparkling wine. He showed people what aerosols are sent into the sky when small bubbles burst in the ocean, which in turn affects the ocean's role in cloud formation and climate change. He also identified the mysterious spot of light that appeared during a radar survey of Titan, the bubbles of nitrogen that ejected from saturn's polar ocean surface, which were about a centimeter or so.
But over the past 20 years, Ligg Bel Air has focused on studying and taking pleasure in studying the bubbles of champagne and other carbonated beverages, including cola and beer. His lab studied all the factors that affect bubbles, from the type of cork stopper, to the ingredients in the wine, to the way the wine is poured. They wanted to know how carbon dioxide bubbles affect the taste of the wine, including the size and number of bubbles, as well as the aromatic compounds floating above the glass.
To find out, they employed gas chromatography and other analytical techniques and took many eye-catching photos. Others around the world have also set their sights on bubbles, inventing robots to ensure that the wine is produced consistently every time they are poured, and focusing on the psychology of people enjoying hissing bubbles.
Champagne researcher Gerald Ligg Bel Air is pointing a high-speed camera at a glass to capture the process of bubble generation and ascent (Source: FRANCE 24)
From grapes to wine glasses: the process of making Champagne
Don Pierre Perrignon was appointed owner of the cellars of a monastery in The Champagne region of France, and is often considered to be the first person in history to try sparkling wine, and he exclaimed: "Drink it like the stars dancing in your mouth!" "As it turns out, the story may have been fictional. The first person to taste sparkling wine may have come from another monastery in France. The first scientific paper on the subject was written by the Englishman Christopher Merett, who came up with the idea in 1662 to the newly formed Royal Society of London, and that perignon had been the owner of the cellar a few years later.
Traditionally, the process of making Champagne involves the first fermentation of the grapes, the making of the base wine, followed by the addition of sugar cane, beet sugar and yeast for secondary fermentation. After two fermentations, the wine should be left to rest for at least 15 months (sometimes decades) in order to allow the dead yeast cells to improve the taste of the wine. To remove the dead yeast, the yeast can be transferred to the bottle mouth, and then by freezing the bottle mouth, the frozen part is ejected, and some gas will leak out in the process.
Before re-inserting the cork, some additional sugar may be added to bring the space of air and liquid in the bottle back into equilibrium, which determines the amount of carbon dioxide that will eventually dissolve. (Each stage will have equations to describe the amount of gas for those who are curious about mathematics)
Scientists have found that a good cork is made from countless small particles stuck together without leaking for at least 70 years. (Source: G RARD LIGER-BELAIR)
Of course, the taste of the final product depends mostly on the ingredients originally added. Kenny McMahon, a food scientist who studies sparkling wine at Washington State University and founded his own winery, said: "Grapes are the most important factor affecting the quality of wine. "It's also a big part of the reason for how much sugar was added in the final stages. McMahon said that in the hustle and bustle of the United States in the twenties, the introduction of Champagne from the United States was really sweet. But modern people's tastes have changed, and there are also great differences between countries.
But bubbles are still important: the proteins in the wine, including dead yeast cells from rupture, stabilize smaller bubbles, form a "mousse" foam at the top of the champagne glass, and create a stronger impact when ingested. According to Siegfredo Fuentes of the University of Melbourne, most of the impressions of amateurs on sparkling wine are actually unconscious evaluations of bubbles.
"Basically, whether you like champagne or sparkling wine or not, you can tell from your first reaction." Fuentes says his research includes digital agriculture and food and wine science. He found that this effect was so pronounced that people would highly value cheap wine without bubbles— if it was made to bubble by the action of sound waves before the wine was poured into the glass. People are even more willing to buy this wine that uses sound waves to bubble. He laughs and says, "Even the worst wine can sell for $50." ”
The foam at the top of the champagne glass is essential for the enjoyment of the wine taster. However, too much carbon dioxide can irritate the nose. (Source: G RARD LIGER-BELAIR)
Usually, in a bottle, the carbon dioxide content per liter of liquid is not less than 1.2 grams, which will produce the desired bubbles and the irritating taste of carbonic acid. But it often happens that the amount of carbon dioxide in the air in the glass has exceeded 35.5%, which stimulates the drinker's nose and brings an unpleasant tingling sensation. If a flute-shaped champagne glass is used, the drinker is more likely to feel unpleasant because the carbon dioxide content above its liquid is almost twice that of the larger diameter French saucer champagne cup. Compared with ambient wine, frozen wine will have a lower carbon dioxide content.
His team found that a quality cork (made up of a large number of countless small particles stuck together) would guarantee that the bottle would not leak air for at least 70 years. After more than 70 years, it is disappointing that the drinking party has become no longer bubbly at all. This is the fate of champagne, which has been buried for 170 years in the shipwreck discovered in 2010.
Ligg Bel Air and his colleague Clara Silinde received a few milliliters of this precious "holy water" to conduct the study. They and colleagues said in a 2015 report that the wines had some interesting properties, including an unusually high ratio of iron and copper (which could come from nails on barrels used to age wines, or even from pesticide residues on grapes). They are also high in sugar, but surprisingly not high in alcohol, perhaps because their fermentation environment is lower than usual. While it's a shame that neither of them has tasted the samples themselves, others who have tasted them use words like "wet hair" and "cheap" when describing the taste.
The 170-year-old champagne bottle salvaged from the shipwreck contained a disappointing bubble-free liquid and tasted "cheap" (Source: ILES ALAND)
For the more common sparkling wine, the method of pouring the wine may have an impact on the bubbles. If 100 ml (about 3.4 fl oz) of champagne is poured directly into an upright flute-shaped champagne glass, a million bubbles will be generated in the glass, according to Ligg Bel Air's calculations. If you take another, gentler way, which is "beer pouring", pouring down the wall of the glass will only produce tens of thousands of bubbles. "If the wine is poured in the wrong way, a large amount of dissolved carbon dioxide will be useless," he said. "Rough spots inside the glass also help create bubbles, and to do this, some glass makers also carve some shapes inside the glass. McMahon said some people don't even wash cups with soapy water to avoid bursting bubbles caused by residual surfactants in the cups.
Champagne taste test
Ligg Bel Air says everything in this science is directly related to how to best serve and taste champagne. Similarly, McMahon believes that the wine industry has changed its approach, based on scientific research, though he can't say which distillery did. Many university departments study wine, and McMahon says there's a reason for that, because their job is to find productive, economically beneficial applications. Fuentes said he knew there were some sparkling wine makers ( though he wouldn't name them ) that would add egg protein to the wine, creating a small bubble that could last an hour.
Fuentes tried to achieve commercial applications from another perspective: his team created a simple robotic device (prototyped from Lego bricks), called FIZZeyeRobot, that ensured that the production of each pour was consistent. His team also uses a video camera to measure the volume and life of the foam on top of the glass, and a metal oxide sensor to detect carbon dioxide, alcohol, methane and other gases in the air above the glass. The team also used artificial intelligence software to use these factors to predict the aromatic compounds contained in the wine itself and, more importantly, the taste of the wine. (While much of this study was conducted with beer, because beer is cheaper and faster to brew, the same applies to sparkling wine.) ）
Fuentes said: "We can predict the acceptance of different consumers, such as whether they will like it and why they will like it. The prediction was made through the team's data set, which came from the personal preferences of the wine tasters, while also taking into account biological features such as body temperature, heart rate and facial expressions. He said that in order to achieve the ultimate enjoyment, this information can be used to determine the best time to drink sparkling wine with dead yeast. He estimates that the system will be put into commercial use sometime in 2022.
Of course, people have their own tastes, and their tastes can be deceived. Many studies have shown that the experience of wine tasting is deeply influenced by the psychological expectations that arise about the appearance or environment of the wine, such as who to be with, the brightness of the room, and the music. Still, Ligg Bel Air, who has been tasting wines for decades, has developed a preference for aged champagnes (with less carbon dioxide) by slowly pouring wine into a large, spacious tulip glass (often used for white wine) at nearly 12 degrees Celsius (54 degrees Fahrenheit) to preserve as many bubbles as possible.
"Since I became a scientist, many people have told me that I seem to have found the most ideal job related to physics because my career revolves around bubbles, because I work in a laboratory full of top champagne," he says. But he added that his true professional pleasure "comes from his obsession with bubbles as he always did as a child."
Originally titled "Champagne bubbles: the science", by Nicola Jones, posted on .2021.12.20 Knowable Magazine. Link https://knowablemagazine.org/article/foodenvironment/2021/champagne-bubbles-science
Translation name comparison table: (Slide to see more)
Gérard Liger-Belair Gerald Ligg Bel Air
Dom Pierre Pérignon don Pierre Perrignon
Christopher Merret Christopher Merett
Kenny McMahon Kenny McMahon
Sigfredo Fuentes Siegfredo Fuentes
Clara Cilindre Clara Silinde
University of Reims Champagne-Ardenne
Reims University
Annual Review of Analytical Chemistry
Analytical Chemistry Annual Review
Uncorked: The Science of Champagne
Opening the Bottle: Demystifying the Scientific Mysteries of Champagne
Saturn's moon Titan Titan
Roaring Twenties flourished in the twenties
Flute flute champagne glass
coupe disc champagne glass
Tulip-shape glass tulip cup
aromatic compounds aromatic compounds
Plate editor| Wang Lejia
The reproduced content represents the views of the author only
Does not represent the position of the Institute of Physics, Chinese Academy of Sciences
Source: Mr. Sai
Edit: Fun Superman