Re: How are wines carbonated?

Sorry to take so long to get back to you, Tony. I had to do a bit of digging for information but I think I can get you pointed in the right direction.

By carbonated wines, I have to assume you are referring to champagne and other sparkling wines (note: "champagne" comes only from the Champagne region of France. Everything else is a sparkling wine, often made from the methode champenoise). These products go through two fermentation steps, instead of just one for other wines. The first fermentation usually takes place in stainless steel tanks but the second fermentation occurs in the bottle. A yeast mixture is added to the fermented blend and the liquid is bottled in heavy-weight glass bottles. Bottles are stored on their sides for the second fermentation and ageing processes, typically for three years.

The bottles are then turned and tilted neck-down little by little every day - a process called 'riddling' - to slowly move the yeast sediment up into the neck of the bottles. Once the bottles are almost completely upside down and the sediment is up near the cork, bottles are sent through a 'disgorging' process. The sediment and corks are removed, a bit of liqueur de dosage is added back to make up for what was removed with the sediment, and the bottles are recorked.

Below are some links you can access for more information about champagne:

Making champagne
Brief description of methode champenoise
Wine-making resources
Champagne trivia

and I found another brief explanation of champagne making in the following book: The Wine Atlas of France by Hubrecht Duijker I am sure your local library can find you something similar. Thanks for your question and good luck with your project - you've chosen a rather complicated undertaking! Kieran