Highlights
- Tank-method sparkling wine gets its bubbles from a second fermentation in a sealed, pressure-rated tank.
- The method is also called the Charmat or Martinotti method.
- Yeast converts added sugar into alcohol and carbon dioxide. The sealed tank keeps the carbon dioxide dissolved in the wine.
- The wine is usually clarified and bottled under pressure after fermentation.
- Tank method often helps preserve fresh fruit and floral character, but it does not determine quality by itself.
- Prosecco is commonly made using the tank method, but Prosecco and tank method are not interchangeable terms.
- Traditional method uses a second fermentation in the bottle; ancestral method completes an earlier fermentation in the bottle.
- Directly carbonated wine gets its bubbles from added carbon dioxide, not a second fermentation.
Quick answer: what is the tank method?
Tank-method sparkling wine is made when a still base wine undergoes its bubble-producing second fermentation in a large, sealed tank rather than in individual bottles.
WineDaddy quick explainer
What alcoholic fermentation changes
Yeast uses fermentable grape sugars and transforms grape juice or must into wine.
Grape sugar
Mainly glucose and fructose provide the starting material.
Yeast activity
Yeast metabolises sugar while conditions such as temperature and nutrients affect progress.
Main outputs
Ethanol, carbon dioxide and heat are produced as sugar falls.
Style effects
Other fermentation compounds can influence aroma, flavour and texture.
RememberSugar → ethanol + carbon dioxide + heat, with other compounds also formed.
The winemaker adds sugar and yeast to the base wine. The yeast consumes the sugar and produces alcohol and carbon dioxide. Because the tank is closed, the carbon dioxide cannot simply escape. It dissolves into the wine, creating its sparkle.
After fermentation, the wine may be left in contact with the yeast deposit for a time. It is then clarified, cooled, adjusted if needed and bottled under pressure. This last step is called isobaric bottling: the wine is transferred while pressure is maintained, helping retain its dissolved carbon dioxide.
You may also see the method called the Charmat method or Martinotti method. These names are widely used for the same modern production approach, although historical accounts distinguish Martinotti’s early tank-fermentation concept from Charmat’s later development of pressure-tank equipment.
How tank-method sparkling wine is made
1. A base wine is prepared
The process begins with a still wine, often called a base wine or cuvée. A cuvée may be a blend of wines prepared for sparkling production.
The base wine provides the wine’s starting flavour, acidity and structure before the second fermentation creates the bubbles.
2. Sugar and yeast are added
Sugar and yeast are introduced for the second fermentation. Yeast converts the sugar into alcohol and carbon dioxide.
This is different from simply adding bubbles to finished wine. In tank-method production, the carbon dioxide is created by fermentation.
3. Fermentation takes place in a sealed tank
The wine is transferred to a pressure-rated tank. In some wine regions and technical descriptions, this vessel is called an autoclave.
The tank is sealed so it can contain the pressure produced by fermentation. Temperature is controlled to manage yeast activity and help the fermentation proceed in a controlled way.
4. Carbon dioxide dissolves into the wine
As the second fermentation produces carbon dioxide, the closed tank retains the gas. Some of it dissolves into the wine, creating the fine bubbles released when the bottle is opened.
The wine may remain in contact with the yeast sediment, known as the lees or deposit. The length and style of this contact can influence texture and flavour.
5. The wine is clarified and cooled
Yeast and other sediment can be removed through processes such as settling, racking, centrifugation or filtration. These operations may be carried out under pressure.
Cooling can help stabilise the wine and reduce pressure before bottling. The precise order and combination of operations can vary.
6. The wine may be adjusted and bottled
A final adjustment, sometimes called dosage, may be used to refine sweetness and balance. It is not correct to assume that every tank-method wine receives dosage in exactly the same way.
The finished sparkling wine is bottled under pressure. This protects the dissolved carbon dioxide and prepares the wine for its final bottle and label.
What does tank-method sparkling wine taste like?
Tank method often suits wines where fresh, primary fruit and floral aromas are important. This is one reason it is strongly associated with aromatic sparkling styles.
However, these are tendencies, not guarantees. A tank-method wine can vary according to:
- grape variety;
- harvest decisions;
- the base wine;
- yeast strain and fermentation temperature;
- time on lees;
- blending;
- clarification;
- dosage; and
- time after bottling.
Tank method alone does not tell you whether a wine is simple, complex, high-quality or inexpensive. It describes where the second fermentation takes place, not the ambition or quality of the finished wine.
Tank method, traditional method and ancestral method
The easiest way to compare the methods is to ask: where does the bubble-producing fermentation happen?
| Method | Where the bubbles are created | Basic starting point |
|---|---|---|
| Tank method | In a sealed, pressure-rated tank | A finished or blended base wine |
| Traditional method | In the individual bottle | A finished or blended base wine |
| Ancestral method | In the bottle, as an earlier fermentation is completed | Partially fermented wine |
| Carbonation | No fermentation creates the bubbles | Finished wine with carbon dioxide added directly |
In the traditional method, sugar and yeast are added to the base wine in each bottle. The second fermentation happens there, followed by further handling and maturation.
In the ancestral method, fermentation begins before bottling. The wine is bottled while it still contains fermentable sugar, and the remaining fermentation produces the bubbles in the bottle.
Carbonation is different again: carbon dioxide is introduced directly rather than being generated by a second fermentation in a tank or bottle.
For a broader introduction to sparkling wine, see What Is Sparkling Wine?. You can also compare the traditional method and ancestral method.
Why is tank method associated with Prosecco?
Prosecco is commonly made using tank fermentation, so the two are often mentioned together. But Prosecco is a wine identity, not another name for the tank method.
Prosecco has grape, geographical and regulatory meanings. In Australia, Wine Australia recognises Prosecco as a grape-variety reference, while treatment in export markets can differ because Prosecco is protected as a geographical indication in some markets.
That means:
Prosecco is commonly made by the tank method, but not every tank-method sparkling wine is Prosecco.
Australian domestic and export labelling rules should not be assumed to be identical, particularly as international arrangements and market requirements change. If you are reading a label, separate the production method from the grape, region and sweetness information.
How to recognise the method on a label
A label may state a production method, grape variety, geographical name or sweetness category. But you cannot safely identify the method from the wine’s appearance, price, sweetness or the mere presence of bubbles.
Look for specific wording such as “traditional method” when it is provided. If the method is not stated, the label may not tell you whether the wine was made in a tank, bottle or by direct carbonation.
The useful distinction is:
- Production method: how and where the bubbles were created.
- Grape variety: the grape or grapes used.
- Geographical name: where the wine comes from or which GI applies.
- Sweetness category: how sweet the finished wine is.
These categories can work together, but none is automatically a synonym for another.
FAQs
Is tank-method sparkling wine the same as Prosecco?
No. Prosecco is commonly made by the tank method, but tank method is a production technique that can be used for other sparkling wines.
Is tank-method sparkling wine lower quality?
Not automatically. The method influences the wine, but quality and complexity also depend on the grapes, base wine, fermentation management, lees contact, blending, dosage and maturation.
Does tank method mean the wine is carbonated?
No. In tank-method production, the bubbles come from a second fermentation in a sealed tank. Carbonated wine has carbon dioxide added directly.
Does tank method have lees contact?
It can. The wine may remain in contact with yeast sediment in the tank, although the duration and handling vary.
What is the difference between Charmat and Martinotti?
They are widely used as names for the tank method. Historical accounts distinguish the people and developments associated with the terms, but they generally describe the same modern category of tank-based sparkling production.