Course:FNH200/Projects/2022/Wine - Prosecco

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A bottle of Prosecco Treviso by Maschio with DOC labelling

Prosecco is a type of carbonated wine, mainly white wine, that is traditionally brewed in Northern Italy. Prosecco, also known as Glera, is a grape variety that is primarily used to produce the Italian flagship sparkling wine, hence is named after it. Glera is a green-skinned, white wine grape containing fruity and floral with hints of honey notes. It is grown in Veneto and Friuli regions of Italy. This particular variety of grape has tendency to produce medium-bodied wines with carbonation ranging from crisp to gentle fizz. Compared to all other sparkling wines such as Champagne, Cava, and Crémant, Prosecco generally has lighter, sweeter, fizzier bubbles which is a characteristic that is generated from being produced in low pressure large tanks. [1] 


General Processing Steps

We can categorize prosecco by their carbonation level. Spumante refers to sparkling prosecco, frizzante is semi-sparkling, and tranquillo refers to still prosecco. Out of all, spumante, sparkling prosecco, is the most popular type of prosecco. [2]

Like champagne, prosecco is produced by mixing yeast and sugar together. What differentiates prosecco production from champagne is the method called Charmat which is the process of fermentation where its bubbles are created in a large stainless-steel tank. After the fermentation, resulting wines are bottled in a pressurized environment by a special bottling line. Charmat method makes it possible for mass production of prosecco which makes the production and the product itself more affordable than other sparkling wine counterparts, such as champagne. [3]

The Six Techniques Used for Production

There are six techniques that wine manufacturers implement to create a diverse array of sparkling wines such as champagne, Lambrusco, prosecco, and Loire. [4] These include the traditional method, tank method, transfer method, ancestral method, continuous method, and carbonation. [4] Prosecco production primarily uses the tank method, but some of the more expensive brands with more complex, yeasty flavours use the traditional method. [5]

Tank Method

1. Harvesting: Prosecco is harvested from the Glera grape variety that originated from Conegliano Valdobbiadene of the Veneto and Friuli regions in Northern Italy. [6] Glera grapes have typical fruity aromas akin to pears, peaches, apples, and melons, as well as floral notes such as honeysuckle, and white flowers. [5] [7] Glera grapes have a higher yield of wine than other grape types. [7] Glera grapes have very delicate skin and are harvested in September when they achieve the appropriate ripeness. [6]

This larger stainless steel vinification tank blends multiple wines from other tanks to form the base wine

2. Pressing: After the Glera grapes are collected, they undergo pressing in order to extract the free-run must. [6] Grape free-run is the grape must that has flowed freely or drained without pressure being applied onto the grapes and is rich in acid and sugar but contains few tannins and aromatic substances (extractives). [8] When pressing is applied harder, more tannins, phenols, higher pH and potassium will be added to the free-run and creates a bitter and astringent taste, low acidity, and aging potential. [9] However, since prosecco only applies light pressing, a low concentration of the aforementioned is present in the free-run must in order to create the fresh, fruity flavour of prosecco. [6] The must is eventually filtered and clarified, which is left to settle in steel tanks at around 14ºC to preserve the properties of the Glera grapes. [6]

3. First Fermentation (Vinification): After pressing is complete, the clear must will be used for the first fermentation process, where yeast and sugar are added. [6] The wine is refined at 18ºC for several weeks and blended with other wines until a “base wine” is formed. [6] The base wine is then evaluated for vintage and defined cuts. [6] The base wine will be transferred into an autoclave (pressure-resistant tank). [4]

4. Second Fermentation: The second fermentation of prosecco, also known as the sparkling stage and in Italian as “presa di spuma” is processed using the Charmat or Tank Method. [6] [10] The tank method for secondary fermentation is cost-effective compared to the more complex sparkling wines such as champagne due to less labour required for processing. [10]

The Charmat process comprises sugar and more natural and selected yeast culture 1-2% added to the base wine in stainless steel pressure tanks. [11] As the yeast consumes the sugar, it releases carbon dioxide, which increases the pressure inside the tank up to 5-6 atm. [11] Since the tank is completely sealed, the prosecco is carbonated to produce sparkling wine. [10]The tank process is carried out at 10-12ºC for maximum CO2 absorption, but it is often conducted at 15-17ºC or higher to speed up the process. [11]

The original alcohol content should be 10-11.5% but will increase by about 1% after secondary fermentation. [11] The pH should be around 3.3 or less, with 0.7 being tartaric acid. [11] The prosecco should have a fresh fruity flavour with no dominating yeasty aromas present. [5] Sulphur dioxide may be added to the tank to prevent refermentation and oxidation. [11]

The quality of the prosecco depends on the time for the secondary fermentation in the tank - the longer the yeast ferments, the greater the preservation of the aroma of the wine and more delicate bubbles. [10] Cooling the wine when the desired atmospheric pressure is obtained prevents rapid fermentation and retains the aroma and freshness of the Glera wine. [11] Secondary fermentation takes ten days to two weeks to complete. [11]

5. Filtering: Sediment is then filtered out of the wine through a pressure-resistant filter. [4]

6. Dosage: The final step is to dose the wine, which entails adding a mixture of sugar/must, depending on the type of prosecco. [4]

Since there is less contact between the yeast and the prosecco, the typical autolytic flavours found in bread that are characteristic of champagne will be less strong and its aromatic, light, fresh flavours will dominate. [5]

Prosecco that has had a longer fermentation process will be of higher quality and thus be more expensive. [10] Since the traditional method requires more steps than the tank method, some argue that the quality of prosecco is lower than other sparkling drinks such as champagne. [10]

Due to its efficiency, prosecco production takes between thirty days to six months, depending on the yeast’s ability to transform sugar into alcohol and carbon dioxide to create a consistent perlage.[6] Perlage is the fizz caused by carbon dioxide bubbles rapidly released from the highly-pressured tank or bottle to the low-pressure surroundings. [12]

Traditional Method

While the majority of Prosecco is made using the tank method to lift the fruity light flavours of prosecco, some of the renowned prosecco styles will use the traditional method that is used to ferment wines that require a richer, complex brioche taste such as the sparkling wine champagne. [5] [13] This process is more expensive than the tank method due to its higher labour demand and longer processing time.[10]

Sparkling wine is riddled automatically using a machine called a gyropalette

1. Base Wine/Cuvée: Grapes slightly under-ripened are picked due to their higher acidity and fermented into a dry wine. [4] The base wines are blended together into a “cuvée”, the final sparkling wine blend. [4]

2. Tirage: Instead of large vats to ferment the base wine, wine bottles are used where yeast and sugar are added to the base wine to create the “liqueur de tirage.” [4] The bottles are bottled and topped with crown caps. [4]

3. Second Fermentation: The yeast will consume the sugar to produce carbon dioxide and ethanol. [4] About 1.3% more alcohol is produced during this stage. [11] The yeast cells die in the wine bottles in this step in a process called autolysis. [11] When the cell wall ruptures, nitrogenous compounds, polysaccharides, nucleic acid components, fatty acids, vitamins, and aromatic compounds are released into the wine. [14] The amino acids in nitrogenous compounds add stability to the foam of the wine and enhance sweetness. [14] The mannoproteins released from the yeast cells prevent crystallization of tartaric salt and stabilize fine and consistent bubbles. [14] The lipids discharged from autolysis stabilize the foam to form a richer, creamier texture of the wine with consistent bubbles and add flavour to the prosecco. [14] Volatile compounds such as heavy esters, and terpenes will add fruity aromas to prosecco. [14] These compounds overall increase the pH and change the low acidity of prosecco into high pH to give a “toasty” or “hazelnut” aroma. [15]

4. Aging: “Lees aging” is the process of leaving dead yeast cells inside the wine. [13] “Gross lees” are larger particles of yeast that travel to the bottle’s bottom and are separated later, while “fine lees” are smaller particles that settle more slowly. [13] They can be left to add complexity to the flavour of wine and even stirred in a process called batonnage to add texture and aroma. [13] For example, non-vintage champagne must be aged for 15 months in bottle and 12 months with lees and vintage for 3 years minimum. [13]

Lees will create the autolytic flavours in bread, brioche, or biscuit, but nutty aromas such as almond can also be created. [13] Lees will also give a complex texture and better perlage consistency than prosecco without lees. [11] [13] Unlike the tank method, sulphur dioxide cannot be added since it will interfere with the brioche, nutty flavours created by the lees aging process. [11]

5. Riddling: The wine is clarified by placing the bottles upside down so that the dead yeast cells can accumulate at the neck of the bottle. [4] The bottle may be repositioned several times until all the sediment collects at the neck. [4]

6. Disgorging: The bottles are left tipped, neck down in racks filled with freezing liquid so that the dead yeast cells, called “lees” collect at the neck when fermentation is complete. [4] The crown cap is then popped off so that the frozen pieces of lees can escape the pressurized bottle. [4] This is to remove the sediment from the wine. [4]

7. Dosage: Exposition liqueur, a blend of sugar and wine, is incorporated into the bottles to add sweetness depending on the type. [4] [11] The bottles are finally corked, wired, and labelled. [4]

The Six Types of Prosecco

Visual sweetness scale of Prosecco[16]

Here are the different sweetness levels of Prosecco according to the International Sparkling Wine Scale (which also applies to Champagne, Cava, and English sparkling wine)[17]:

  • Brut Nature (Very Dry Prosecco): 0-3 grams of residual sugar per litre.
  • Extra Brut (Extra Dry Prosecco): 0-6 g/L of residual sugar.
  • Brut (Relatively Dry Prosecco): with 0-12 g/L of residual sugar.
  • Extra Dry (Notable Sweetness): 12-17 g/L of residual sugar.
  • Dry (Sweeter): 17-32 g/L of residual sugar.
  • Demi-sec (Sweetest Prosecco): 32-50 g/L of residual sugar.

In conclusion, relatively same production methods, but with different residual sugar added, or different grapes have been used.

Generally, prosecco can be categorized into 6 different flavours, and they have relatively the same production methods, but with different residual sugar added, or different grapes have been used.

Packaging and Storage

Prosecco Packaging Material

In general, Prosecco is packaged in a glass bottle. Glass bottle is sturdy, inert and highly unreactive, making it the perfect packaging material for prosecco. [18] In addition, glass is timeless and will not degrade over time, which is best for long-term storage. Besides, it provides a high-end feeling, which consumers highly prefer. [19] From a marketing perspective, prosecco is an ideal packaging material although it comes with the disadvantage of having a high carbon footprint. [20]

How to store Prosecco before opening

Before opening, Prosecco is best to preserve its quality when stored in a dark and cool place. Although refrigeration is a common approach, the vibration created from the refrigerator could potentially wedge the cork of the bottle, which decreases the amount of carbonation of Prosecco as the bottle shakes, leading to a change in taste. In addition, the flavour profile will be altered by the light exposure in the refrigerator. Simply storing the bottle in a dark, cold place is the best approach for storing Prosecco. The bottle only needs to be chilled before serving to ensure it is not too warm to drink. [21]

How to store Prosecco after opening

After opening, prosecco is best preserved in the refrigerator in a household setting, especially with sparkling prosecco. The rate of losing carbonation slows down as the temperature of the bottle drops. As such, keeping the bottle ice cold is critical to maintaining bubbles in the prosecco. Losing bubbles in prosecco not only affect the mouthfeel of the beverage but also influence the taste. The more carbonation is lost, the sweeter the prosecco. Additionally, resealing the bottle plays an important role in preserving prosecco after opening. Using hermetic corks would be most effective to conserve the carbonation in the bottle. Alternatively, using a plastic wrap covering secured with a rubber band would be a good choice. [21]

Prosecco Grading

Sample of grading scale for qualities of Prosecco between DOC and DOCG [22]

Different kinds of Prosecco are categorized by region. These are marked by the certain acronyms, such as DOC (Denominazione d’Origine Controllata) and DOCG (Denominazione d’Origine Controllata e Garantita).

These acronyms are used to identify and legally recognize the quality of the wine that comes from their respective regions. It also ensures that the product is authentic and has followed the standard winemaking processes and regulations.[23]

DOC and DOCG are the main classification labels on Prosecco products and they differ by the geographic areas they cover. They can also be accompanied by the specific region they came from which can further indicate the increase in the quality it has depending on that region.[7]

DOC, translated to “Controlled Designation of Origin”, is the most general kind of Prosecco that comes from a broader area where mass production is possible. Prosecco DOC is the most common label that can be found on Prosecco products.[23]

DOCG (“Controlled and Guaranteed Designation of Origin”) covers a much smaller geographic region where the wine production has an extremely strict set of rules to follow to ensure the highest quality of Prosecco. A variety of factors like the soil, fertilizer, climate, manual harvestation, and exclusive taste-testing are all considered to enhance the quality of the grape and thus the high quality of the wine.[23]

Fun Facts

  1. “Prosecco is made from a blend of grapes that must be at least 85% glera, with the rest being local and international varieties including verdiso, bianchetta trevigiana, perera, chardonnay, pinot bianco, pinot grigio and pinot noir.” [24]
  2. “The majority of prosecco is produced using the Charmat method. Also called the tank method, this winemaking process involves a second fermentation in large closed tanks that trap carbon dioxide, a byproduct of the fermentation process, in the wine. The wine is then filtered and bottled under pressure with the desired level of dosage for sweetness. The fermentation is usually quick, lasting about one month, but the lungo (long) variation can last 9 months, leading to more complexity in the wine.” [24]
  3. “A new trend, especially among low-intervention or “natural” producers, is a return to the much older ancestral method. This style, called col fondo (“with sediment”), is made by bottling still-fermenting wine, which becomes fizzy in the bottle. The sediment adds texture and yeasty flavour to the wine. Col fondo wines do not receive additional dosage, so they are dry. Some Prosecco DOCG wines may, alternatively, be carbonated using the traditional method, where the second fermentation occurs in the bottle, similar to Champagne.” [24]
  4. “Depending on the producer’s style and amount of residual sugar, alcohol levels can range from 8.5% to 12.5% for fully dry wines.” [7]

Exam Question

Match the type of prosecco with the appropriate sweetness level (Match Number)

1) Brut Nature
2) Extra Brut
3) Brut
4) Extra Dry
5) Dry
6) Demi-Sec

a) 12-17 g/L of residual sugar

b) 0-3 g/L of residual sugar

c) 32-50 g/L of residual sugar

d) 0-6 g/L of residual sugar

e) 0-12 g/L of residual sugar

f) 17-32 g/L of residual sugar

To view answers, click the down arrow in each box after submission.
This question is a good way to learn and familiarize the different types of prosecco and the terms used to categorize them. We can also learn how the sugar level affects the taste/mouthfeel of the prosecco.


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  11. 11.00 11.01 11.02 11.03 11.04 11.05 11.06 11.07 11.08 11.09 11.10 11.11 11.12 Amerine, Maynard (April 19 2022). "Wine". Britannica. Retrieved August 8 2022. Check date values in: |access-date=, |date= (help)
  12. "What Is Perlage? Definition And Science Explained". Advanced Mixology. December 15 2020. Retrieved August 8 2022. Check date values in: |access-date=, |date= (help)
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  19. "5 Benefits of Using Glass for Your Wine Case". June 24 2020. Check date values in: |date= (help)
  20. "Glass, Plastic Bottles or Bag-in-Box; How Environmentally Friendly Are They? ​Wine Packaging Trends Part I". October 25 2020. zero width space character in |title= at position 78 (help); Check date values in: |date= (help)
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