The first sparkling wine I made nearly took my eye out with the explosive force when we popped the cork. After Ms Gazette had stopped laughing and the cat was found we had a great strawberry champagne that was far beyond what I had imagined I could make and was better than the commercial bottle I used as a control. The second was a little nerve racking as it was 12 bottles for a friends wedding but that all went swimmingly too… he still talks to me at least.
I already plan to make an elderflower shampagne and might make a dandelion fauxseco this year and have just turned last years gooseberry wine into the latest batch of er… sparkling wine. Crisp dry whites are probably best but I may well try and carbonate a second run medium bodied elderberry & blackberry wine about this time next year. You’re making it so go crazy as the world is your lobster.
I am assuming that like me you are making a small batch of champagne – six to twelve bottles using a British gallon or two of wine. If you are making a bigger batch have a read through this exhaustive guide by Jack Keller: http://winemaking.jackkeller.net/sparkling.asp
The process is surprisingly easy using a simplified “méthode champenoise” to create a second fermentation in the bottle. As the new fermentation happens the gas is trapped and dissolves in the wine creating all those lovely bubbles. As there is a lot of pressure created you must use champagne bottles. They are made with thicker glass, stronger necks and may well be shaped or have a domed base to deal with the pressure. Along with those you need some hollow plastic corks and cages. The bottle is stored upside down so that the yeast collects in the corks cavity and either compacts enough to be removed when opened or the bottle can be riddled – freezing the wine in the cap then swapping it for a new sediment free one. The cage and upturned bottle keeps the cork in place so the pressure does not create a wine time bomb popping the cork out.
There are a few yeasts that can be used for the second fermentation and the most popular is EC1118 though others like Premier Curvee, WLP715 or CL23 are all available. The yeast does not need to be used for the the initial fermentation when making the base wine so you can match two yeasts to make the best base wine and then carbonate with the sparkling wine yeast. Most people will just happily plough through with EC1118 as it is easy, dependable and tastes excellent.
The gooseberry wine was over six months old and at the age I normally bottle. When making it I did not use any campden after the primary fermentation so that there is little to hamper the new yeast as it is already being introduced to hostile alcohol rich environment. The wine was totally dry at 0.99 gravity so I know how much it will carbonate as the sugar is directly responsible for the carbon dioxide produced thus pressure created. No sediment was falling being nice a clear and almost totally degassed naturally. 17g of sugar will make an American style four atmosphere fizz and 25g creates a French style six atmosphere fizz. Sparkling wines are always more carbonated than bears that will be between one and a half to three atmospheres. If using a young wine with lots of carbon dioxide still dissolved plan for the US style four atmospheres for safety.
Two days work will need to happen before bottling so make sure you have the nights set aside. Also kit needs to be scrupulously sanitised as you go.
First a starter needs to be made to kick start the second fermentation. Separate 750ml of wine from the demijohn into a sanitised litre bottle or jar. Reseal the demijohn and pop it away safely, as there is head space here is a slight chance of oxidation but unlikely. The wine needs 13g of sugar and perhaps a 1/4 tsp of yeast nutrient stirred in before adding the yeast. Some yeasts like Vintners Harvest/Mangrove Jacks have the nutrient already present so have a check. When the yeast is added seal the bottle as you would with any other fermentation with a bung and airlock and allow the yeast to sit and hydrate for a couple of hours. Some yeast may float some may fall but if it is happy it will start to swell and dissolve and it is then ready to stir in thoroughly.
There will never be a heavy bubbling during this second fermentation as the yeast is really pushing towards its limits in an alcohol rich environment. There may be small bubbles rising, some may collect on the surface and there will certainly be gentle airlock activity. The must should be kept at more or less room temperature rather than in a cooler bulk ageing environment.
After 24 hours add 40ml of sanitised water to dilute the new alcohol and add another 13g of sugar to feed the yeast and leave for another 24 hours. This time will allow the yeast to acclimatise as much as possible and minimise the chance of a stuck second fermentation.
It might be a good time to start and clean and sanitise the bottles and caps at this point. The bottles should be spotlessly clean as always and the caps can either be boiled for ten minutes and left to cool or sanitised in campden or no rinse sanitiser. If boiling the caps to sterilise them be sure to make sure they are cool and thus strong enough to push into the bottles. Hot caps are soft and deform easily!
Once the starter is viable and happy the remainder of the wine should be prepared. Decide on either a four or six atmosphered wine. Four atmospheres will need 17g of sugar added per bottle thus 102g per British gallon. A European style six atmosphere wine will need 25g per bottle thus 150g per British gallon. Add the sugar to the demijohn and stir into the wine thoroughly. Then add the starter and stir thoroughly again.
This sugar and yeast rich wine is now ready to pour into the champagne bottles and cap. Personally I choose to use a jug rather than an auto-syphon as it allows the wine to be stirred between pours dispersing the dense sugar and yeast evenly. Cages are essential should be used twisting to get a good tight seal – this may take a few attempts as the brittle wire will tear if over tightened. Once capped upend and stand on their heads and cellar. After a month give the bottle a swift twist to encourage the sediment to settle into the caps but resist the temptation to shake the bottles.
Fermentation may take about a month but the originating fruit will determine how long the wine should be matured. Rhubarb and gooseberry will need at least 18 months from the initial fermentation, elderflower about a year and strawberry possibly as little as six to nine months.