Bubbles

"Bubbles in a glass of champagne may seem like the acme of frivolity to most people, but in fact they may be considered a fantastic playground for any fluid physicist"

Professor Gérard

Liger-Belair

"Some one million bubbles form in the average glass of champagne" Daily Telegraph

This is one of those posts inspired by a picture - one from those glossy magazines I was flipping through the other day. When I saw it it just stopped me in my tracks. I have no idea whether it has been manipulated at all, but the end result, in my view anyway, is art. The pattern of the bubbles is so symmetrical, the colours are so rich and the bubbles seem to be going down rather than up - which is surely not the case. Anyway it inspired me to do something on bubbly wines, or maybe just bubbles. Search the net and see what comes up is my dictum and I certainly found a lot. A lot of it was detailed, and I refer you to the articles here and there, but there was also a whole lot of really interesting stuff - even for non-scientists like myself. For it is basically all very scientific. It's a marriage of science and art. They call winemaking an art, but really it is a science it seems.

As I searched the net I was, of course, quickly overwhelmed with details of the winemaking kind - see Wine Folly for a pretty comprehensive explanation of how sparkling wines are made. Or if you live here in Melbourne, go to Domaine Chandon in the Yarra Valley where they have a pretty good self-guided tour that shows you how it's done. And yes they still do some of the riddling (turning the bottles every day) by hand, but they also have huge machines that do it for them. And since this is a company owned by Moët et Chandon I assume that they do it in France too.

I sort of knew it all, but one thing I learnt today that I didn't know is that there are actually four different ways of making those bubbles:

• Méthode Champenoise (the one they show you at Domaine Chandon and which I thought was the only way),

• Metodo Italiano (for Prosecco and Lambrusco, etc.)

• Tank method

• Carbonation - which you might think is common for cheap bubbly, but apparently is not really that common.

Actually I think the Tank method is possibly the most common for the cheaper ones. And we all know we can't use Champagne to describe anything that is not made in the Champagne area of France, but I have a feeling we can't even use 'méthode champenoise' to describe how it's made. Not sure if they fought that one and won or not. But that's not about the bubbles, that's about the method.

So back to the bubbles. I found an excellent article in the Daily Telegraph which, whilst reporting on the work of Professor Gérard Liger-Belair of the University of Reims, explained all about the physics, if that's what you call it, of the bubbles. Bigger is, in fact better, which is contrary to past popular belief. This is because:

"the effect of the larger bubbles is to drive the important aromatic compounds that give champagne its distinctive smell and flavour upwards into the drinker's nose when they take a sip."

Previously a mark of quality was fine bubbles - which when you think about it is probably an aesthetic thing - fine = skilled, time-consuming and therefore expensive. There are still 'experts' out there singing the praises of fine bubbles I have to say. And I guess they do look more beautiful - and expensive.

The carbon dioxide trapped in the wine is released explosively when the bottle is opened and the rest of it travels to the surface in those magic bubbles. Originally there was great danger that the cork would explode outwards at any time, but in 1844 Adolphe Jaquesson invented the muselet (muzzle) to prevent this. The muselet is the wire bit around the cork that holds it in.

"Just before you uncork the bottle, the pressure inside is five to six times as great as the pressure in the room. That's why champagne bottles have to be so thick – each one is a prison fortress, keeping the pressurized fluid confined. As soon as the cork is gone, the huge amount of gas dissolved in the liquid can start to escape." Helen Czerski, The Guardian.

If you would like an even more detailed and scientific explanation of it all then go to the Wine Lessons site. Obviously the University of Reims professor is the world authority on all of this, because he is also much quoted in this article. He has written papers and even a whole book on the subject. Who knew there was so much to explore? This article came up with this little gem which rather grabbed my fancy:

"If you wipe your glass with a rough cloth leaving many cellulose fibers, there is no doubt there will be more bubbles!"

But this is not necessarily a good thing. For I then found another excellent article by Helen Czerski in The Guardian where the focus is on the glass you drink it from. She states:.

"bubbles won't form unless they've got a starting point. Any slightly rough surface will do, so you'd better have polished the glass or the bubbles will tell tales on you. If there are any specks of dust or fibre inside the glass, you'll see a stream of bubbles coming from that point. The only acceptable place for bubbles to start is the centre of the bottom of the glass, and the manufacturers of posh glasses will etch the surface there to roughen it and make sure the bubbles start where they're supposed to."

And yes a flute is better than the old Marie Antoinette type glass, which does not have sufficient height for enough bubbles to form and is so wide that the aromas, released escape into the atmosphere. But if you are lucky enough to taste a really, fine, old champagne, then apparently you should,

"use a wide glass that curves back in towards the top, but only fill it a little way. The shallow liquid means that small slow bubbles can deliver aromas slowly, allowing complexity to develop, and the large space at the top of the glass traps it for you to enjoy." Helen Czerski, The Guardian

So there is obviously a lot to learn about bubbles. When that Guardian article was written, Helen Czerski was making a BBC documentary on the subject - not champagne - but the bubbles.

There is something magical about the bubbles in a bottle of sparkling wine. And the pop of the cork as it leaves the bottle, although, again, if you are doing it properly there really shouldn't be that much of a pop; The bubbles are light and dazzling, and they fizz as they sputter in the glass. So your sense of hearing comes into it as well. In fact all five senses are involved in drinking bubbly - taste (of course), smell (also of course), hearing, sight (the beautiful colours and the even more beautiful bubbles and touch (the fizziness on the tongue). Sparkling wine has to be light and effervescent - to float somehow - so pink or white (well white really means a whole range of colour from barely any colour at all to deepest gold or amber). I think red sparkling wine is no good. It's just too heavy,

So to end with the art - which was, after all, the inspiration of this article - here is something else from the University of Reims, and Professor Gérard Liger-Belair, via the Daily Telegraph. A picture of bubbles on the surface of champagne. Like flowers.

"the bubbles form a regular hexagonal pattern on the surface. When a bubble collapses, it creates a cavity that stretches and strains the neighbouring bubbles, producing a pattern that looks similar to the petals of a flower." Daily Telegraph

"liquid decadence" Guardian