The Oxney view on sparkling bubbles
Have you ever asked yourself why bubbles make sparkling wine such a delight to drink? We wouldn’t blame you if the answer was a resounding no. Like any well-adjusted person, you’re no doubt far too busy enjoying what’s in your glass to be distracted by such thoughts.
However, these are the questions that keep us wine geeks up at night – and it turns out the answers are quite fascinating. Read on to see if you agree!
What puts the bubbles in sparkling wine?
There are a few ways to add the sparkle to wine but for quality producers like us the traditional method is the only way to go.
This method sees a still wine undergo a second fermentation in a sealed bottle, with the CO2 released from the process dissolving in the liquid as the pressure in the bottle rises to around 6 bar. There the CO2 will quietly reside until the bottle is opened, the pressure equalises with the air and the gas finds an escape route.
Most commonly, this is in the form of bubbles. And the science of how those bubbles enhance the pleasure of drinking sparkling wine is extraordinary.
Where do bubbles actually come from?
Bubbles aren’t the only way for CO2 to escape from a wine. They only appear when there is a microscopic ‘point of nucleus’ to form on, typically a fleck of cellulose left behind by a cleaning cloth. Glass makers tend to etch the inner surface of the glass directly above the stem to create a steady central stream of bubbles upwards.
So what happens if there are no imperfections in the glass for bubbles to form on? Champagne bubble physicist Gérard Liger-Belair constructed an ingenious experiment to find out. After sterilising wine glasses in a powerful acid to remove any contagions, he poured in sparkling wine… which resolutely failed to sparkle. The wine looked like a still wine, no bubbles appeared and the dissolved CO2 dispersed unseen from the surface.
How do bubbles affect the wine in your glass?
Interestingly, the most honest answer to this question is ‘It depends on the type of glass’. Different glass shapes concentrate and disperse bubbles in different ways.
Old-fashioned coupes are old-fashioned for a reason: the wider surface area of the glass and the liquid inside mean bubbles form from more points, CO2 is released faster and your fizz quickly falls flat. At the other end of the scale, champagne flutes concentrate the bubbles up the narrow channel at the centre of the glass for more vigorous effervescence.
Neither of these options is ideal for reasons explained below. Nowadays most experts in the art of drinking sparkling wine recommend drinking from a glass with a wide bowl tapering to a narrower rim, such as a decent white wine glass.
How do bubbles enhance flavour?
Bubbles in sparkling wine don’t just look great. They influence the aromas and flavours in the glass in numerous ways. First, they create upward current on their journey from the bottom of the glass, collecting all kinds of aroma molecules on their way. When the bubbles pop on the surface, they eject these molecules several centimetres up into the air just above the glass, where your grateful nose is waiting.
This is why tall, thin flutes are now considered suboptimal. In generating such a powerful stream of bubbles, they launch plumes of flavour through a narrow space, with most of it flying out and getting lost in the air around the glass. A wider fluted glass, on the other hand, delivers just the right amount of aroma mist to the rim, maximising your enjoyment.
Another effect of bubbles is their ‘bite’ on the tongue. This is more than the feeling of bubbles bursting. In fact it’s carbon dioxide producing a tingling sensation by activating nerve endings on your tongue. Sparkling wines literally transform your mouth’s biochemistry in their quest to bring you pleasure.
So there you have the Oxney Organic take on bubbles. Not just a treat for the eyes but the engine of just about everything that makes sparkling wine so uniquely enjoyable to drink. We’ll raise a glass to that!