When it comes to the most representative wine additive, sulfites come to mind.
If you love vin nature or naturally made wines, whether sulfites have been added to a wine is likely something that concerns you greatly.
In recent years, vin nature and naturally made wines have gained popularity worldwide, and in Japanese wine as well, wines made this way have come to be frequently seen.
And when discussing these wines, the topic of sulfites always comes up.
In this article, aimed at beginners, we would like to offer a brief explanation of the relationship between vin nature or naturally made wines and sulfites.
Understanding How Sulfites Work
Sulfites, one of the additives used in wine.
Consumers often seem to view them as "sulfites = additives → therefore bad," but let us first judge after learning how they actually work.
What Are Sulfites?
Sulfites are substances produced when burning sulfur and are food additives used in numerous foods.
Sulfites have been used since ancient times for purposes such as disinfection, and in wine, they are added to prevent oxidation, deterioration, and microbial contamination.
Although it is said that they have been added to wine since antiquity, there are opinions that this theory is dubious, and it is also said that they only began to be used in earnest in wine around the 19th century.
The Role of Sulfites in Wine (1)
As explained above, the purpose of adding sulfites to wine is to prevent oxidation and microbial contamination.
However, rather than preventing oxidation outright, sulfites function to inhibit the damage caused by oxidation.
As an example, here is the sequence of events when wine is oxidized by oxygen in the air:
Phenols contained in the wine come into contact with oxygen and react
↓
Components with strong oxidizing effects, such as quinones and hydrogen peroxide, are generated
↓
If left unchecked, they continue to react with various substances in the wine, degrading its aroma and flavor
↓
Furthermore, a component called acetaldehyde, produced by the reaction between alcohol and oxygen, is generated
↓
Giving rise to burnt or sour aromas characteristic of oxidation... and so forth
Because sulfites (strictly speaking, free sulfur dioxide) easily bind with these products that are harmful to wine, they suppress the spread of damage and protect the wine from deterioration.
Since it is impossible to 100% avoid oxidation during the winemaking process and after uncorking, without the addition of sulfur dioxide, the rate of wine deterioration advances markedly.
The Role of Sulfites in Wine (2)
While sulfites are often added before bottling after the wine is completed, they are also used at various points throughout the production process.
A prime example of this is addition at the must stage.
Must refers to the crushed fruit before alcoholic fermentation begins, but when harvesting and crushing grapes, grapes in poor condition can sometimes get mixed into the must.
Such poor-quality grapes have high concentrations of oxidative enzymes (oxidases), and if countermeasures such as the addition of sulfites are not taken, oxidation reactions will occur within the must.
There is a risk that oxidizable components in the wine will be affected by oxidative enzymes to emit unpleasant aromas or produce compounds that degrade the taste, resulting in low-quality wine.
Because sulfites possess antibacterial properties, they destroy these enzymes and neutralize wild yeasts and bacteria that adversely affect wine fermentation, making them indispensable in winemaking. (They are also used for brewing equipment.)
Do Sulfites Strip Away the Charm of Natural Wine?
Sulfites are an indispensable additive in winemaking.
On the other hand, as mentioned at the beginning, many naturally made wines such as vin nature contain only small amounts of sulfites or none at all.
Even on the certification mark for "Vin Méthode Nature," a natural wine certification system launched around spring 2020...
- Wines with no added sulfites at all
- Wines with a maximum of up to 30 mg/l of added sulfites
Two such categories are provided, stipulating that sulfites should not be used as much as possible in order to claim the name vin nature. (Naturally, methods such as pasteurization, reverse osmosis, and filtration are also not permitted.)
While some experts voice opinions that it is quite an ambiguous certification system and lenient regarding the amount of sulfites added, there appears to be general agreement on the direction that "the addition of sulfites is not very desirable" when claiming to be naturally made wine.
Why is the addition of sulfites not recognized in natural wine...?
Because It Eliminates the Charm of Wild Yeast
As mentioned regarding the function of sulfites, sulfites have the action of wiping out wild yeasts.
In recent years, however, it has been reported that certain wild yeasts among yeasts play an important role, such as imparting complexity to the aroma and flavor of wine.
Additionally, in a well-known study, Matthew Goddard's team researching yeast in New Zealand announced that yeasts (Saccharomyces cerevisiae) with unique genes exist depending on the land, and they may carry out fermentations unique to that land.
The view is that if one wipes out wild yeasts with sulfites and brews wine with cultured yeasts, rather than flavors unique to that land (terroir), the result will be cookie-cutter wines found anywhere.
Because There Is Little Need to Use Them
While using sulfites is important for sound winemaking, some producers seem to hold the view that there is no need to use sulfites in the first place.
To begin with, the situation where sulfites are most commonly added is prior to bottling, but given how sulfites function, they eventually cease to exist.
Sulfites exist in two forms, free sulfur dioxide and bound sulfur dioxide, and not all of the amount actually added works; only a tiny amount of active free sulfur dioxide molecules does the job.
Naturally, after binding with various substances in the wine, the free sulfur dioxide molecules change form, and ultimately the sulfites disappear. (They disappear within 3 months at the earliest, or within 2 years at the latest.)
Since sulfites are produced naturally during the fermentation process in the first place, considering that fact, some hold the view that it makes no sense to forcibly add them and ruin the wine's flavor.
Philosophy
Many producers who make vin nature and natural wine value terroir. (Although some producers claim this for marketing purposes...)
In certifications that define vin nature, including "Vin Méthode Nature," the only wine additive permitted is sulfites, and none others are allowed. (Many additives are permitted in wine.)
As long as naturally made wines claim to express terroir and vintage to the utmost, it is only natural to want to bottle them in as natural a state as possible.
Moreover, while there are various theories, consumer psychology—such as believing sulfites are bad for health, cause hangovers, or are used to mask deteriorated wine—may also be related.
Before Deciding Good or Bad, First Learn About Sulfites
Sulfites are additives that play an important role in making sound wine.
To make sound vin nature and naturally made wines, the skill, experience, and scientific knowledge to brew wine without relying on the function of sulfites are likely necessary.
Personally, while the wines I find "interesting" are natural-style wines made without sulfites, that does not mean I think standard wines that use sulfites according to regulations are not delicious.
Judging good or bad is up to the individual.
However, rather than relying solely on preconceptions, isn't it also necessary to understand sulfites before deciding on the wines you choose for yourself?
References
Natural Wine: An introduction to organic and biodynamic wines made naturally | Isabelle Legeron, translated by Reina Shimizu
“Vin méthode nature”, the natural wine method, new private natural wine label, with fuzzy rules