Carbonic maceration
Homemade wine with a fruity aroma
Carbonic maceration as a procedure for the production of young red and pink wines with a fruity, refreshing bouquet has been known for many years. The procedure was discovered by accident in 1934 in France during the canning of table grapes at a low temperature (0⁰C) and in a CO2 atmosphere .
After a few months of storage in such conditions, it was noticed that the bunches had a sharp (stinging) taste and as such were unusable for eating, but vinification produced a wine with an unusual but very fine taste and smell.
The man credited with the discovery of carbonic maceration is the French scientist Michel Flanzy who in 1934 used carbon dioxide as a grape preservation technique. However, this was not implemented until the 1960s.
Around 1980, I received a few bottles of Beaujolais Villages wine from my husband who was on a temporary assignment in France at the time. He started his work abroad in a French winery.
At that time, I was already working as a technologist in the wine cellar “GODOMIN” in Smederevo in Serbia. Tasting Beaujolais Villages wine,
I was delighted by the unusually strong fruitiness on the nose and the feeling of fresh Gamey grapes on the palate. The wine was young, but with a very rich bouquet that I did not feel with the wine in my winery in Godomin.
This intrigued me to study the making of this kind of wine, but I did not do it in the winery where I worked but in my own winery. And here is my story enriched with the experiences of other manufacturers. Enjoy!
My experience
Bottles of Beaujolais Villages wine
Like many winemaking techniques, carbonic maceration offers seemingly endless variations, depending on what best suits a particular grape variety, its terroir, and the style the winemaker is looking for.
The key to using the carbonic maceration technique properly is to allow enough time for intracellular fermentation, but not so much time for the bacteria to take over and start producing unwanted compounds like ethyl acetate and acetic acid (volatile acidity or VA).
In my experience with this carbonic maceration technique, after day 1, when I put the whole bunches in and saturate the vessel with carbon dioxide, I let the vessel warm up naturally for a few days and then open the fermenter.
During this time, intracellular fermentation takes place and 1.5 to 2% vol. ethanol. After 5 to 6 days, I put a small amount of yeast culture into the fermenter so that the yeast can continue to bring the fermentation to an end.
The yeast can be selected or you can multiply your autochthonous yeast previously prepared from the wider of your grapes. I use selected yeast for red wines.
This ensures that I capture the interesting aromas created during that first intracellular fermentation, but then I introduce yeast strong enough to bring the fermentation to an end so that the wine is below 4g/l of reducing sugar.
The whole bunch and preserved whole berries are used!
Very often, semi-carbon techniques are also called simply “carbon”.
Even in Beaujolais, the region most associated with this method, producers traditionally do not practice full carbonic maceration, but a semi-carbonic technique where whole bunches are placed in wooden, concrete or steel vessels without the addition of CO2 .
Due to the pronounced fruity aroma and freshness, wines produced by carbonic maceration are best when they are still young, such as
beaujolais primeura and beaujolais noveau (in France), i.e. wines labeled as vini novelli (in Italy).
Beaujolais is a medium to strong alcoholic French red wine, produced by the carbonic maceration process in the south of the famous Bourgogne wine region. It was named after Beaujeu , the capital of the ancient province of Lyonnais.
The difference in quality is table red wine, which only carries the label “b”, which is light and best when it is still young. This is the reason why
Beaujolais parties have been organized in a special way since 1951.
.
Beaujolais nouveau wine (Wikipedia)
Beaujolais Villages is the most prized and usually bears a closer indication of the place of origin as it is produced by numerous rural farms.
What is the essence of carbonic maceration
Carbon grape berry on the left and normal grape on the right.
There are many variations of carbonic maceration, and particularly interesting are semi-carbonic macerations that can be performed without the use of carbon dioxide.
Maceration is carried out by placing grapes with undamaged berries
(not muddy ) into a stainless steel vessel (with appropriate equipment, with thicker walls and a sloping bottom) filled with CO2 gas.
Part of the grapes at the bottom of the vessel (2 – 3%) is crushed (due to the pressure of the mass of grapes above) and gives a must that starts to ferment with the formation of ethanol and CO2.
The berries at the bottom are crushed under the weight of those at the top. They undergo yeast fermentation, which creates carbon dioxide along with alcohol. Meanwhile, the berries towards the middle and top remain intact and undergo intracellular fermentation.
Fermentation inside the cells of undamaged berries is not caused by yeasts, but by endogenous enzymes in the berry, and this is precisely what results in the creation of specific fruit aromas characteristic of each variety and terroir.
If you’ve ever tasted a red wine that sparkled brilliantly with ultra-fruity, bubblegum aromas or was lightly crisp with cinnamon, vanilla, and earthy, herbaceous flavors, you’ve probably encountered carbonic maceration.
At the end of this process, the grapes contain a smaller amount of acids compared to the initial state (especially the malic acid is reduced), and in addition to the intense smell of grapes, new aromatic compounds are formed that resemble strawberries and raspberries.
Additional stomping of the beak after the Carboniferous phase.
Therefore, it is a process of processing black grapes by which they are macerated in a CO2 atmosphere in order to carry out intercellular fermentation.
Such a processing procedure is carried out with black varieties with a firmer skin of the berry (carignan, grenache, gamay, prokupac, etc.) with the aim of producing wines with better aroma, vinosity and color.
The resulting CO2 (in addition to the added one) quickly saturates the environment, as a result of which living cells of undamaged berries are forced to change their metabolism, i.e. to intercellular fermentation (autofermentation). In such a filled and closed container and in a CO2 atmosphere , the berry cells soon die; their membranes burst, and juice enriched with aroma and colors pours out.
After partial or complete fermentation (7-20 days), at a temperature of approx. 30-32⁰C, the usual operations follow – swelling and squeezing, after which the conversion of sugar into alcohol is completed within 2-3 days.
How carbonic maceration is performed
Whole bunches are placed in a vessel saturated with CO2, and at the end of the filling the grapes are in three forms: Whole undamaged bunches that are in the gaseous phase, poor in oxygen, and highly saturated with CO2 (they are most exposed to the effects of anaerobic metabolism).
Crushed bunches are at the bottom of the vessel (due to the weight of the grapes above). Crushed grapes are macerated, and alcoholic fermentation caused by yeasts begins. Fermentation must be controlled to avoid bacterial growth (by addition of the desired bacterial strain or sulfurization).
The whole bunches are dispersed in the liquid phase (the spread formed from the crushed bunches). Those clusters are exposed to less intense anaerobic metabolism.
It can also be done this way: Carbonic maceration
of grapes enclosed in a bag that needs to be filled
with carbon dioxide.
In the first phase of fermentation, three parallel processes take place:
1. Anaerobic metabolism (intercellular fermentation) of whole, undamaged berries (either those in a CO2 atmosphere , or those immersed in crushed berries),
2. Maceration (leaching of colors, aromatic ingredients, etc. from the solid parts of the grapes into the wine) and
3. Alcoholic fermentation spreads more widely (at the bottom of the container) thanks to yeast activity, and apart from the above,
malolactic fermentation also begins .
The temperature and duration of this first phase determine the sensory characteristics of the future wine, and a relatively high temperature (up to 32⁰C) is most often applied.
At the end of the first stage of fermentation, after draining, we get a fraction of the single-flow shrew that represents an almost over-boiled young wine (spec. weight 1.000 – 1.010), and after straining we get a shrew that still contains a lot of unboiled sugar (spec. weight 1.020 – 1.050). After squeezing, sugar can be adjusted if necessary.
After draining and pressing, in the second stage of fermentation, the secondary alcoholic fermentation is completed, i.e. addition (under the influence of yeast) and malolactic fermentation, as well as the single-flow fraction from the pressing (each on its own, or mixed).
The temperature of this second phase should be lower than the previous one and is 18-20⁰C. After the completion of this second phase, the first air transfer follows, followed by other transfers as needed.
What are the chemical processes of carbonic maceration
Vinification with carbonic maceration is a technique that takes advantage of the processes that occur spontaneously in undamaged berries (not muddy grapes) when they are subjected to
anaerobic conditions (CO2 atmosphere ).
The complex of these changes is the anaerobic metabolism of the grape berry, and consists of various phenomena of synthesis, decomposition and diffusion: intercellular fermentation, transformation of organic acids and nitrogenous substances, diffusion of CO2 and polyphenolic substances, formation of new aromatic compounds.
Anaerobic metabolism of the grape berry
These complex changes in the grape berry (anaerobic metabolism) occur only under the influence of the enzyme systems of the berry.
The intensity of anaerobic metabolism depends on:
undamaged (berry damage),
-ambient saturation with CO2 ,
-temperature and altitude
-duration of temperature.
Intercellular fermentation refers to the conversion of sugars into ethyl alcohol (and other secondary products, as in alk. fermentation caused by yeasts), but under the influence of endogenous enzymes of the berry, not yeast, and takes place inside the intact grape berry.
In this way, a maximum of 2 vol.% ethyl alcohol is produced (the highest concentration of ethanol occurs at temperatures of 30-35⁰C), glycerin 1.5-3 g/L, acetaldehyde 15-20 mg/L.
The degree of anaerobiosis (temperature and concentration of CO2 has a decisive influence on the amount of ethanol produced. At a lower temperature (10 – 20⁰C), and an initial lower CO2 concentration of 20%, not even half of the ethanol created at 100% ambient saturation is created.
The total acidity of grape berries is reduced due to the decomposition (catabolism) of malic acid (without the simultaneous formation of lactic acid as in malolactic fermentation).
Succinic, shikimic and fumaric acids are formed, while the content of tartaric and citric acids remains unchanged (
Peynaud and Guimberteau, 1971 ). The sum of ascorbic + dehydroascorbic acid decreases and after 10 days at 35⁰C is 50% of the initial valu.
Carbonic maceration wines are rich in fruit aromas.
The temperature has a particular influence on the development of these processes, so for example for the Carignan variety, after 8 days of anaerobic metabolism (carbonic maceration) at a temperature of 35⁰C, the amount of malic acid decreased by 50%, compared to a decrease of 15% at a temperature of 15⁰C.
The content of pectic substances progressively decreases, and the amount of free amino acids increases, with a simultaneous decrease in the ammonia and protein form of nitrogen.
Polyphenolic compounds move (diffuse) from the skin of the berry to the cells of the flesh (pulp), and the transition is faster and more intense the higher the temperature and the longer it lasts, where the colored substances (anthocyanins) diffuse faster than tannins.
New aromatic compounds are formed
Volatile aromatic esters with a very intense smell are present in carbonic maceration wines: vinylbenzene, phenylethyl acetate, benzaldehyde,
ethyl cinnamate (ethyl ester of cinnamic acid), and this last ester is proposed as an indicator that the wine was produced by carbonic maceration technology.
In addition to volatile esters, various volatile phenolic components are present in larger quantities in carbonic maceration wines: 4 – vinyl guaiacol, 4 – vinyl phenol, 4 – ethyl guaiacol, 4 – ethyl phenol, eugenol, methyl and ethyl vanillates.
These compounds with a very intense smell resemble the smell of cloves (eugenol), strawberry marmalade (ethyl cinnamate), and various other fruity smells (amyl caprylate, amyl butyrate, ethyl laureate).
These aromas are very pronounced in young wines, and they are quickly lost as they age, so wines produced by carbonic maceration are suitable for quick consumption.
Conclusion
Carbonic maceration produces young wines that are consumed during autumn and winter because they quickly lose their fruity character during long aging.
Also, these wines are served as festival wines and on the occasion of an important date or jubilee.
With carbonic maceration, wines can be produced at home and enjoyed during the festive, New Year and Christmas days. There is no need for expensive equipment except for a carbon dioxide bottle with pressure gauges and a CO2 filter.
Instead of carbon dioxide, “dry ice” can be used in bags (Australian patented technology) that are inserted into the vessel where the maceration will take place.
After melting the dry ice, in a hermetically sealed container, the temperature should be raised from 30 to 32⁰C and continue to maintain the same temperature until the end of the maceration, i.e. until the time required for leaching optimal amounts of polyphenolic substances in which aromatic, colored substances and tannins are present.
Source:
https://bit.ly/4lL26BX
How to order an e-book
By clicking on the “Buy Now” button, you can pay via PayPal or pay with a debit or credit card.
The price of the E-book is $9,99
After payment, a page with links to download the e-book opens.
By clicking on the link, you will receive a book in pdf format that you can permanently download to your computer or smart mobile phone.