The Reality of Microbial Contamination
How many of you have ever heard the term "microbial contamination"?
Working in winemaking, albeit in a small corner of the world, one encounters various challenges. Wine often carries an image of luxury and high society (though perhaps that term is already outdated), but the reality is remarkably diverse. It ranges from wines crafted like works of art by producers with the temperament of artisans or artists, to those mass-produced industrially under the principle that quantity is king. The fact that all of these are lumped together under the single word "wine" may well be the source of unfortunate misunderstandings and misconceptions in society. These are the kinds of thoughts that occasionally cross my mind.
Yet even within this diversity of winemaking, certain taboos exist. These are practices that, if committed, will almost certainly result in unpalatable wine—a certainty in the worst sense of the word. One such taboo is the microbial contamination I mentioned at the outset.
Wine as Food
Wine is, needless to say, a food product. In other words, something that enters the human body.
Therefore, wine must be sanitary. While it's true that society sometimes treasures moldy or partially spoiled items as delicacies or delicacies of the highest order, these are exceptions. Fundamentally, no one wants to deliberately consume something contaminated with microorganisms. We can consume "live lactic acid bacteria that reach the intestines" precisely because we know what they are and that they're safe.
If someone were to claim "this contains multiple species of unidentified microorganisms that will reach your intestines," it would immediately become a case for consumer protection agencies.
In wine production, microbial contamination refers to a state where microorganisms that should not be present have entered the wine at some point during the manufacturing process and, in most cases, have proliferated there. The typical route is that microorganisms proliferate in the production equipment or winery, and by using equipment or locations in this unsanitary, contaminated state to make wine, the microorganisms transfer to the wine, resulting in contamination.
To give clear examples: the unintended introduction of film-forming yeasts, as described in this article. Additionally, the introduction of a yeast called Brettanomyces is also classified in most cases as an instance of microbial contamination.
The Importance of Sanitation Management
The method for avoiding such microbial contamination is, simply put, cleaning.
First cleaning, second cleaning. Third and fourth are also cleaning, and fifth is cleaning. It's crucial to keep the winery and all equipment sanitary. This is no different from keeping a household kitchen or drain clean. The most important task at a winery before harvest is thorough cleaning.
To deliver wine made hygienically in such sanitized locations with sanitized equipment—and to deliver it to customers in a sanitary state—we use sulfites, known as antioxidants. The chemical name is sulfur dioxide, written as SO₂.
In Japan, this substance frequently comes up in conversation as the cause of headaches from drinking wine, so many of you may have some familiarity with it.
Because this substance is often labeled as an "antioxidant" in Japanese, many people understand it as something to prevent wine oxidation. However, it actually serves multiple roles, one of which is the suppression of microbial activity in wine.
When making sweet wines, it's necessary to stop the activity of actively working yeast during fermentation, and SO₂ is used for this purpose as well. Furthermore, empty wooden barrels after bottling wine provide an ideal environment for microbial growth, so we either store water with dissolved SO₂ in them or burn SO₂ inside the barrels to sterilize them with the smoke (this is called fumigation).
Even knowing that consumers may well view its use negatively, we winemakers endure the criticism and make daily efforts to produce sanitary wine while using such substances, all to deliver safe and secure wine.
Sanitation Management Undermined
Despite all these efforts to avoid microbial contamination and deliver clean wine to our customers, I frequently witness scenes that completely undermine all of this work. Moreover, these scenes exist in every context surrounding wine. Indeed, I even see them inside wineries.
That scene is the reinsertion of corks into opened wine bottles—in reverse.
Wine bottles are typically 750ml. In some parts of Japan, there may be 720ml bottles as well. In any case, it's just under one liter. Converted to beer, that's just under two large mugs. For someone who isn't particularly fond of alcohol, this is a bit too much to finish alone in one sitting. Therefore, a drinking pattern emerges where one doesn't finish the entire bottle on the day it's opened, but rather seals it at an appropriate point and enjoys it on subsequent days.
If it's a screwcap, there's no problem at all. Simply retighten the cap and put it in the refrigerator.
The problem is with corks.
Anyone who has pulled a cork from a wine bottle has almost certainly experienced this: the shape of a cork extracted from a bottle is not a perfect cylinder. In most cases, the end that was inside the bottle is thicker, while the outer end where the corkscrew was inserted is thinner.
This means the easier end to insert into the bottle is the thinner outer end. In other words, the cork gets reinserted into the unfinished wine bottle upside down from its original position.
This is an extremely common sight. I see it in ordinary households with little interest in wine, in the homes of wine enthusiasts, in the hands of certified sommeliers, at wine shops, and even at wineries. Most people probably do this without a second thought.
But consider this for a moment: what is currently inside that wine bottle?
A Warning from the Producer
I make wine, but I'm not particularly strict about how wine should be handled.
Once it leaves my hands, I believe how it's treated is that person's freedom. I don't think it's appropriate for producers to interfere that far. Therefore, I generally turn a blind eye to what others do. Yet there is one thing—almost the only thing—that I absolutely never do myself and advise those around me not to do either. That is reinserting corks upside down.
This isn't about respect for the producer. It's simply because it's unsanitary. Yes, it's unsanitary.
We producers are extremely careful about sanitation issues in wine production.
This applies not just to the wine itself, but to everything that goes inside the bottle. We wash bottles before filling them with wine, and we naturally sterilize and disinfect all equipment and instruments, including the filling nozzles. Furthermore, we handle corks so as not to touch the top and bottom surfaces.
However, this only extends to the inside of the bottle. The outside of the bottle is beyond our control. In other words, we have no knowledge of the sanitary condition of the bottle's exterior. Including the outer surface of the cork.
The Contradiction Between Wine and Sanitation
Wine is a troublesome beverage in that long-term aging is often considered desirable. However, this aging doesn't occur in sanitarily controlled environments like raw meat storage. Rather, it happens in places with low temperatures but high humidity, sometimes dusty locations where bottles are stored, in a sense, haphazardly. How many people could honestly claim that the surface of something stored in such an environment for several years remains sanitary?
Let me be blunt: the surface of a cork that faced the outside of the bottle is extremely unsanitary. Exposed to humidity for years, it may have grown mold. Insects may have touched it. Certainly, dust will have adhered to it.
If this were food, probably no one would try to put it in their mouth—they would throw it in the trash. At the very least, people would surely wash it thoroughly. Then they would heat it to sterilize it before consuming it. After all, it's loaded with live microorganisms that will reach the intestines.
Yet what did you do to that opened bottle?
Admittedly, when a cork is reinserted upside down, the bottle isn't laid on its side, so the cork may not directly touch the liquid surface. But can you still say that bottle, that wine, is sanitary?
True, we add sulfur dioxide to wine. This stops the activity of microorganisms in the wine. However, this is a calculated amount added after making every effort to reduce the quantity of microorganisms as close to zero as possible. It's not designed to handle large quantities introduced from the outside. We are utterly powerless against this act of terrorism.
The Fundamentals of Sanitation
Microbial contamination is one of the concerns in winemaking.
This isn't unique to wine—it's a natural concern anywhere food is handled. And consumers watch this aspect closely. If a hair were found inside packaged food, it would become a major issue. Food must be sanitary. This is an important theme related to our health.
Wine is often accompanied by extensive commentary.
How does it look? How much noble and mysterious aroma, flavor, and story does it contain? There are many people who, once they start talking, cannot stop. Qualifications and examinations related to wine are also popular. Many people study extensively, and these receive considerable attention. Yet not a single one of these people seeks wine that will upset their stomach or wine with unpleasant tastes and aromas.
We wine producers face these various demands and requests daily. And we employ various means to meet them.
Yet there is something that all these people, in most cases, overlook.
The outside world is filthy.
