Sparkling wine from your own wine: planning bottle fermentation safely

By Magnus von Kageneck, cellar master (who he is) · Updated: September 2026

If you want to open a bottle from your own cellar on New Year's Eve, you fill it in mid-October. The must fermenting in the demijohn right now won't do for this; it will become your base wine for next New Year's Eve. For this one you need a wine that is already finished today.

Counting backwards: the calendar to New Year's Eve

Bottle fermentation starts two to five days after filling and lasts three to six weeks; wines high in alcohol take longer, sometimes months. After that comes riddling until the yeast rests on the stopper, and that too takes a few weeks.

• End of September, two to three weeks before filling: check the base wine and clarify it if necessary.
• Shortly before filling: yeast starter, one to two days ahead with dry yeast, four to five with a liquid culture.
• Mid-October: dissolve the sugar, fill, seal.
• Until early December, longer for high-alcohol wine: fermentation at about 15 °C, shake daily.
• December, only once fermentation is over: move somewhere cool and riddle.
• Between Christmas and New Year's Eve: disgorge, top up with wine, reseal.

Every week you lose in October will be missing in December for riddling. This calendar is the tight version for a young, fresh sparkling wine. The usual practice is several months on the lees after fermentation, which gives a deeper fermentation bouquet.

The base wine matters more than any technique

A simple apple wine fermented to dryness works well, for example one from the summer (how it is made). Dessert wines are out; among fruit wines, only light table wines are suitable. This is what the base wine has to bring:

• Fermented to dryness, checked with an Oechsle hydrometer and a residual sugar test (what the instruments show). Residual sugar ferments along with the rest and drives up the pressure.
• No more than 10 to 11 % vol; more alcohol slows the second fermentation.
• 7 to 10 g/l acidity, otherwise it tastes flat. If a fruit or grape base wine is below 6 g/l, raise the acidity before filling (Getting acidity under control).
• No acetic taint: acetic acid below 0.8 g/l.
• Little sulphur dioxide (SO₂): total no more than about 50 mg/l, free below 25 mg/l.
• Clear to brilliant, so that the yeast settles cleanly later on.
• No sorbic acid: a wine stabilised with potassium sorbate (as when sweetening) will not start fermenting again and can smell of geraniums.

1 g of potassium metabisulphite per 10 litres already adds 50 mg/l, and the yeast produces some SO₂ itself. A wine that is meant to become sparkling gets only 0.5 g per 10 litres at the first racking and no second dose; sulphited twice, it is no longer suitable. Measure the free SO₂ before filling (what sulphur does in wine). Above about 25 mg/l, bottle fermentation struggles to get going. For printing, the booklet “Measure, Don't Guess” is available among the Maischewerk booklets.

Four grams of sugar, one bar

Two additions of sugar are at work in the bottle. The tirage sugar ferments completely and creates the pressure; the dosage is added after disgorging and determines the sweetness. For the first, the rule is: 4 g of ordinary white sugar per litre gives about 1 bar of overpressure at 10 °C, from the very first gram. At 20 °C the same bottle is under roughly a third more pressure, because warm wine holds less carbon dioxide in solution.

Use 20 g per litre, so 150 g for 7.5 litres of base wine. The maximum of 24 g per litre applies to all the sugar that ferments in the bottle: residual sugar counts, and so does the juice in the yeast starter. With 0.3 litres of apple juice, around 30 g of sugar, added to 7.5 litres of wine, you end up at (150 + 30) ÷ 7.8 = 23 g per litre, about 5.8 bar at 10 °C and almost 8 bar at 20 °C. So the 20 g you add is also the most you can add.

Be careful with older instructions: they treat the first 4 g per litre as producing no pressure and so arrive at 28 g for 6 bar. In reality, 28 g gives about 7 bar at 10 °C and over 9 bar at 20 °C. Calculate without this baseline. Dissolve the sugar completely in part of the wine first, otherwise individual bottles will end up with more pressure than calculated.

Bottles and closures: no improvising here

The empty weight tells you whether a sparkling wine bottle is up to the job: lightweight bottles of 460 to 550 g are single-use bottles for carbonated wine, standard bottles of 650 to 850 g are the choice for home use. Weigh every bottle empty, because even one that looks thick with a domed base can be light, and discard any bottle with a crack or chip. Wine, beer and lemonade bottles cannot withstand the pressure, not even with a swing-top or screw cap.

Close with polyethylene stoppers, driven in with a rubber mallet or a hand stoppering tool. For fermentation and riddling, use the open hollow stopper with its small cap insert, into which the yeast will later slide. Secure every stopper immediately with a wire cage, twisted tight with pliers; without a cage, no stopper holds.

Full bottles belong in a closed crate away from walkways, never in the sun, next to a radiator or in the car. Wear safety goggles and gloves when handling them. If one does burst, move the rest somewhere cooler.

The second fermentation: cool and shaken

The yeast gets going in 0.3 litres of clear apple juice without preservatives for 7.5 litres of wine, with one portion of sparkling wine yeast, under a cotton wool plug at about 20 °C. Grape juice brings far more sugar and throws the calculation off. Fill only once the starter is visibly fermenting. Fruit wines get 1 g of yeast nutrient salt per 10 litres, so 0.8 g for 7.5 litres.

On filling day, stir the dissolved sugar, nutrient salt and fermenting starter in thoroughly and fill bottle after bottle with the siphon. Leave about 15 ml of air and secure each stopper before you fill the next bottle. For 7.5 litres, have an eleventh bottle ready, because the starter increases the volume.

The bottles then rest at about 15 °C, no cooler at first and as evenly as possible. Shake them daily, at least every other day, so that the yeast stays in contact with the sugar. Do not open a bottle to check. Because you cannot reliably tell from the outside when fermentation has finished, they stay like this for at least six weeks, longer if in doubt. Only then move them somewhere cool, because cold can halt an unfinished fermentation.

Riddling and disgorging in December

For riddling, put the bottles somewhere cool in a crate, necks angled downwards. Give each one a short, sharp turn about its long axis every day and gradually tilt it more steeply. After a few weeks it stands vertically, and the yeast sits as a deposit on the stopper.

Only disgorge bottles whose fermentation is definitely finished; if in doubt, wait until after New Year's Eve. The cold helps with disgorging: about 6.5 bar at 20 °C becomes around 3 bar at −4 °C. Chill the bottles upside down outdoors on a frosty night to about −4 °C. Or put them upside down in the chest freezer for three to four hours; this way you lose only 30 to 40 ml when opening. If it gets much colder, the contents freeze and burst the bottle; don't forget any in the freezer.

Wear safety goggles and sturdy gloves. If the yeast plug is frozen, turn the bottle up so it points upwards at an angle and only then open it, with the mouth pointing away from people, into an open crate or a bucket lying on its side. If the deposit is not frozen, open it upside down and, in the same movement, turn the bottle so it points upwards at an angle. Only ever one bottle at a time.

For New Year's Eve bottles that have spent only a few weeks on the lees, brut is the safe choice: you top up with wine only. If any yeast is still alive, it will ferment any sweetness, and 30 g per litre would add a further 7.5 bar at 10 °C. The sweet dosage is intended for bottles that have spent months on the lees: 225 g of sugar dissolved warm in 90 ml of water gives about 225 ml, made up fresh because it crystallises on standing. 22.5 ml per bottle, measured with a liqueur glass, equals 30 g per litre.

Reseal with a closed stopper and a new wire cage; after that, store the bottles cool, lying down or upside down, never upright.

Name and tax: clarify beforehand

Legally, “Sekt” means only quality sparkling wine made from grapes. What you make from apple wine is sparkling apple wine; the German name of the sparkling wine yeast (Sekthefe) only describes the type of yeast. For tax purposes in Germany, wine and wine-like beverages of more than 1.2 up to 15 % vol count as sparkling wine if they have at least 3 bar at 20 °C, and, regardless of pressure, in any bottle with a sparkling wine stopper and wire cage. The law contains no exemption for private households. Ask the main customs office (Hauptzollamt) before your first batch.

Safety note: potassium metabisulphite is a hazardous substance, as are potassium sorbate and the acids used for acidification; the signal word, pictogram, hazard statements (H) and precautionary statements (P) are given on the product page and the packaging. Never bring potassium metabisulphite into contact with acid, not even in the same measuring cup, otherwise toxic gas is released. What counts is the label of the product delivered, not a figure from an article. The greatest danger with sparkling wine remains the pressure in the bottle; the limits above apply without exception.

Legal basis: Regulation (EU) No 1308/2013, Annex VII, Part II; German Sparkling Wine and Intermediate Products Tax Act (Schaumwein- und Zwischenerzeugnissteuergesetz), § 1.

Magnus von Kageneck is Maischewerk's cellar master character. The texts in this series are written with the support of artificial intelligence and are checked for technical accuracy before publication.

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