The addition of brewing alcohol in sake production and sugar supplementation in winemaking—these practices seem to be quite antagonized in many cases. They give the impression of being the dark side of fermented beverages, untouchable territories, so to speak.
This likely stems from the fact that people harbor some form of negative impression toward externally supplementing sugar levels and alcohol content that should naturally be obtained through cultivation and brewing processes, regardless of the purpose or reason behind such practices.
Alternatively, it might result from the interpretation that sugar supplementation is proof of low-quality wine, based on the fact that certain countries and regions prohibit sugar addition in categories that claim to produce high-quality wines.
Indeed, sufficiently ripened grapes can achieve juice sugar levels that eliminate the need for sugar supplementation. Nevertheless, conducting sugar supplementation despite this could understandably be perceived as proof of unripe grapes.
But is this really the case?
This article aims to shed new light on this so-called dark side of sugar supplementation.
What Is "Sugar Supplementation"?
As I have mentioned several times before, is it clear what sugar supplementation actually refers to?
Put simply, sugar supplementation means exactly what the words suggest: "supplementing" "sugar."
However, this is an extremely personal impression, but I find this term "sugar supplementation" to be quite an unwieldy expression. This is because the term contains no information about "when" or "to what" sugar is being supplemented.
Sugar Supplementation Definitions Clearly Distinguished in Foreign Languages
For example, in German, there are two distinct terms for what we call sugar supplementation:
Anreicherung Süßung
Anreicherung refers to sugar supplementation performed with the purpose of increasing alcohol content, primarily conducted before fermentation, though it may occasionally be implemented after fermentation.
On the other hand, Süßung refers to the act of adding sweetness to something that has already completed fermentation and is established as wine. These are referred to in English as chaptalisation and wine sweetening, respectively.
This article focuses on Anreicherung/chaptalisation, so unless otherwise specified, "sugar supplementation" in the text should be understood to refer to this practice.
The Purpose of Sugar Supplementation from a Definitional Perspective
As already explained, sugar supplementation means supplementing sugar. Its purpose is to increase the alcohol content after fermentation.
While the content is fine-tuned according to regional characteristics in different countries and regions, basically similar detailed rules are established everywhere. However, in all cases, the permissible scope of this sugar supplementation is limited to compensating for alcohol content after fermentation, not for adjusting taste or aroma.
In other words, sugar added for supplementation purposes must be completely converted to alcohol through fermentation and should not remain as residual sugar.
While there are various technical operational considerations regarding this point, at least the legal premise is as stated above. This is also a point where the purpose clearly differs from the addition of brewing alcohol in sake production.
Rules Surrounding Sugar Supplementation
I mentioned earlier that the somewhat negative impression associated with the term sugar supplementation might be influenced by the existence of certain rules governing this practice.
Here, I will introduce the content established by German wine law as an example.
First, the rules regarding sugar supplementation in German wine law are as follows:
- Prohibited for Kabinett and higher Prädikatswein (quality wine with distinction)
- Prohibited for wines with alcohol content above a certain level
- Maximum alcohol supplementation through sugar addition is 3.5% vol.
Let us examine each of these in detail.
The Fallacy That Sugar Supplementation Is Prohibited in Premium Wines
The classification of wines in German wine law is determined based on the juice sugar content of grapes at harvest.
This stems from the fact that Germany was such a cool region that it was once considered the northern limit of grape cultivation, making it difficult to fully ripen grapes.
The reasoning is that grapes that could be well-ripened—that is, grapes that could achieve high juice sugar content—in such a difficult environment where low temperatures made grape ripening challenging, were valuable in themselves, and wines made from such grapes naturally deserved to be treated as high-grade, rare products.
Given this background, if sugar supplementation were applied to wines or grapes classified as high-grade Prädikatswein, it would undermine the entire foundation of this classification system.
In other words, the reason for prohibiting sugar supplementation for the Prädikatswein category is based on systematic requirements and the judgment that it is unnecessary given the grade classification. This fact does not distinguish between high and low quality of grapes or wines.
It should be noted again here, as there is much misunderstanding, that German wine grade classifications are based solely on the juice sugar content of grapes at harvest, and there is no relationship between these grades and wine taste. The commonly stated relationship that Spätlese means sweet wine has no legal basis whatsoever.
No Sugar Supplementation for Sufficiently High Sugar Content
The upper limit for alcohol content in wines eligible for sugar supplementation as stipulated in Germany is 12% vol. for red wines and 11.5% vol. for other wines.
This has the same meaning as the grade-based restrictions mentioned above, based on the idea that grapes with juice sugar content sufficient to exceed 12% vol. alcohol content would not need sugar supplementation.
Incidentally, achieving 12% vol. alcohol content corresponds to approximately 90 Oechsle or around 22 Brix in terms of juice sugar content. In terms of sugar quantity, this is about 200 g/l. This is a sufficiently sweet level, and conversely, even a slight decrease from this amount would fall within the range where sugar supplementation is permitted.
From this point, you can understand that the equation "grapes requiring sugar supplementation = non-sweet grapes" does not necessarily hold true.
Sugar Supplementation Cannot Be Done Without Limits
It would be problematic if one could ferment sugar water and claim it to be wine.
Therefore, the necessary regulation is setting an upper limit on the amount of alcohol that can be obtained through sugar supplementation.
The amount of alcohol permitted to be supplemented through sugar addition is differentiated by grape production regions: in Germany, it is 3.5% vol. except for some southern regions, and 2.5% vol. in other regions.
This upper limit, established not as German wine law but as higher-level EU wine law, is further reduced to 2.0% vol. in more southern countries.
Within the EU, annual temperatures become higher and annual sunshine hours longer as one moves south. This relatively reduces the difficulty of grape ripening, thereby lowering the fundamental necessity for sugar supplementation.
Is Sugar Supplementation Necessary?
The image that unripe grapes immediately require sugar supplementation seems surprisingly widespread, but I find this puzzling.
It is true that cooler climate regions do indeed have more opportunities for sugar supplementation.
However, even in such regions, if we assume complete fermentation of all sugar content in the juice without leaving any residual sugar, sugar supplementation is far less necessary than commonly believed.
For example, let's say grapes are harvested at 60 Oechsle, 15 Brix juice sugar content.
Complete fermentation of this juice would yield 60.4 g/l alcohol, just under 8% vol.
Normally, harvesting at such a low level as 60 Oechsle would virtually never occur, at least in Europe, because this level indicates grapes that are still very green and far from ripe. The acidity would be too high, resulting in terrible taste balance.
However, conversely, this would still yield just under 8% vol. alcohol content.
Waiting just a little longer for harvest would easily bring alcohol content up to around 10% vol. While opinions may vary on how to view these figures, from a winemaking perspective, there is no necessity to resort to sugar supplementation, which faces societal criticism or cold reception.
One could simply release the wine at 10% vol. alcohol content.
So why do winemakers practice sugar supplementation?
The following reasons can be cited:
- Weather conditions necessitating harvest at low sugar content
- Necessity for residual sugar management
- Low sugar content resulting from prioritizing grape taste and flavor
Increased Need for Sugar Supplementation Due to Climate Change
Some may find this surprising, but recent climate change has increased the necessity for sugar supplementation in some aspects.
One factor is cases where diseases occur due to prolonged rainfall just before harvest, forcing earlier harvest timing to maintain grape health. Another is cases where summer temperatures become too high, causing sugar content to rise rapidly and excessively.
Pressure for Reduced Ripeness Due to Early Harvesting
While many people associate climate change with warmer winters and extreme summer heat, reality extends beyond this.
In addition to such temperature fluctuations, changes in rainfall amounts and timing occur.
Recently, prolonged rainfall during flowering periods and summer, particularly after grape ripening begins, has increased both directly and indirectly, raising the risk of diseases such as mold.
In response to these situations, there are increasing instances where early grape harvesting must be implemented.
Waiting for full ripeness could lead to excessive disease damage, potentially creating fatal situations.
Advancing harvest timing naturally reduces fruit ripeness and lowers juice sugar content. As a result, sugar supplementation becomes necessary.
Early Harvesting to Secure Acidity
On the other hand, there are increasing cases of early harvesting to secure necessary acidity levels.
As a physiological response in grapes, acidity decreases in inverse proportion to advancing ripeness and increasing sugar content.
Recently, high summer temperatures have accelerated grape ripening speed. This causes grapes to become somewhat overripe relative to desired ripeness in just a few days, resulting in insufficient acidity securing.
It should be noted that regarding winemaking technique regulations, acid supplementation is often more strictly controlled than sugar supplementation. In other words, while wineries can relatively easily perform sugar supplementation within rules, acid supplementation may require applications or may not be permitted at all, making it less feasible.
Therefore, in cases where acidity is prioritized, deviation from harvest timing that results in decreased acidity is far more problematic than slight juice sugar deficiency due to grape under-ripeness.
The result is intentional early harvesting to secure acidity, with insufficient sugar content compensated through sugar supplementation.
This becomes more prominent in cases like Champagne, where alcohol content can be supplemented through secondary fermentation.
Sugar Supplementation to Maintain Residual Sugar
Adding sugar to sweeten wine after fermentation is generally not permitted.
The basic rule is that if you want to finish wine sweet, this should be adjusted through fermentation management alone.
Note In actual winemaking operations, blending dry and sweet wines to sweeten the overall product is commonly practiced, but this is treated as non-contradictory since the "sweet wine" for blending is sweetened through fermentation management.
This leads to the concept of supplementing through sugar addition the sugar content lacking in juice necessary to maintain the residual sugar amount desired by the winemaker.
At first glance, this seems to lead to the opinion that added sugar ultimately remains as residual sugar—essentially no different from adding sugar to finished wine.
In reality, it is difficult to distinguish whether sugar remaining as residual sugar in wine originates from original grapes or from sugar supplementation.
Therefore, the following rules are required:
- Sugar added during supplementation must consist of 99.5% or more fermentable components
- Addition amounts must be based on precise calculations with appropriate quantities added without excess or deficiency
- Added sugar must use legally specified substances with basically identical composition to sugar naturally contained in grapes
These rules establish the premise that sugar added through supplementation is "entirely" appropriately converted to alcohol. Even if sugar added through supplementation were to remain as residual sugar by replacing original grape-derived sugar, since they are chemically identical components, mutual exchange is possible, and the logic holds that sugar from supplementation does not remain as residual sugar.
Is Alcohol What Matters Most?
I believe the most important point in debates surrounding sugar supplementation is whether there exists a rule stating "wine must have high alcohol content."
Must red wine have 14% vol. alcohol content?
Is red wine with 10% vol. alcohol content unacceptable?
What makes wine wine is not alcohol content.
Certainly, there are aromas, tastes, and flavors brought about by alcohol content, so I do not categorically deny alcohol. However, whether these should be given top priority is highly questionable.
When cultivating grapes and determining harvest timing, sugar content should not be the primary consideration.
Of course, minimum sugar content is necessary. Furthermore, higher sugar content relates to higher ripeness, and aroma components also relate to ripeness, so all these factors are interconnected. Therefore, using sugar content as a harvest indicator is natural. However, more important than this is harvesting at the optimal timing for grape-derived aromas and flavors—this is the most crucial point for subsequent winemaking.
Nevertheless, delaying harvest for reasons such as "aroma and flavor are at their peak now, but sugar content is the only insufficient factor, so the wine would only reach around 11% vol. alcohol content" is utterly foolish.
For creating excellent wine, one should harvest at that timing and perform sugar supplementation.
Sugar supplementation is a legally recognized winemaking technique, and if conducted within rule-compliant ranges, there is no justification for criticism.
If one believes that naturally acquired alcohol content determines wine quality, that is one perspective. However, if not, there is no need to unnecessarily view this technique negatively or avoid it.
Conclusion
Particularly among Japanese people, I am often asked about the presence or absence of sugar supplementation in winemaking contexts. Conversely, I barely recall receiving such questions from Germans or other Westerners.
As someone involved in winemaking, honestly, I don't understand why there is such focus on the presence or absence of sugar supplementation.
Moreover, when I respond that sugar supplementation was used, there is invariably a tone-down in atmosphere.
Is the presence or absence of sugar supplementation really that concerning?
Are you predicting grape inadequacy based on sugar supplementation presence?
Or does learning this allow more accurate understanding of harvest timing?
Honestly, if you want to know harvest timing, simply asking directly about that point would suffice, and the same applies to grape conditions.
The fundamental purpose of sugar supplementation is alcohol content compensation, but the reasons for doing so are separate. Without particularly inquiring about these reasons, simply asking about sugar supplementation presence and ending the conversation there leaves only a puzzling impression.
As I have written, except in intentional cases, grapes are virtually never harvested in such under-ripe, low-sugar states that absolutely require sugar supplementation.
Yet the point that sugar supplementation is still performed is what deserves attention. There are always positive reasons behind it.
Criticisms that wine should be pure and sugar supplementation is unacceptable should rather be directed toward barrel-aged winemaking.
I have no intention of denying the perspective held by those who maintain that sugar supplementation is negative. That view is perfectly fine.
However, I would like you to thoroughly consider why it is negative. Does sugar supplementation truly have negative aspects?
