When you take a sip of delicious wine, you might not think about the processes involved in making that wine, other than perhaps what ingredients and flavors were chosen during the production process.
But wine is the perfect example of biotechnology. One of the reasons for this is fermentation!
What is fermentation?
Fermentation is a chemical process in which molecules like glucose disintegrate anaerobically. It can be defined as the foaming that occurs when beer or wine is produced.
But, fermentation is just one of many ways in which biotechnology has developed and continues to develop wine in exciting new ways. So, with that as our starting point, let’s look at the important roles biotechnology plays in wine production.
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How Is Wine Made?
Over the last two decades, technology has made huge leaps when it comes to making wine. The quality of wine has been improved and wine has been infused with many different flavors.
Yeast, which is single-celled microorganisms that form part of the fungus family, form a big part of how wine is made. Let’s take a look at the wine-making process.
- Grapes are collected and crushed. They are put in a de-stemmer, which is machinery that removes the stems from grapes.
- When making white wine, white grapes are put into a press so that their juice is drawn out and their skins are left behind. This juice is then put into tanks where sediment settles at the bottom.
- After a while, this juice is racked, or filtered, and put into a new tank.
- When making red wine, the grapes are lightly crushed but their skins aren’t removed. The skins and juice all go into a vat where fermentation can begin.
What Is The Fermentation Process?
Interestingly, fermentation is considered to be the oldest type of biotechnology.
Put simply, fermentation basically involves converting sugar into alcohol, but there are many ways in which the juice from grapes can be fermented. Sometimes yeast is added to the vats of red or white wine to ferment them, for example.
When making wine, traditional microbiology is based on the use of yeast species known as saccharomyces cerevisiae. However, another commonly used microorganism is oenococcus oeni, which helps to do malolactic fermentation.
This lactic acid bacteria grows in the wine and it encourages fermentation that actually improves the wine’s quality.
For red wines specifically, carbon dioxide gets released during the process of fermentation.
This encourages the grape skins to float to the surface. Winemakers have to punch these skins down to ensure they remain in contact with the juice, thus enhancing the flavour and quality of the wine.
What About Genetic Modification Of Wine?
Biotechnology is focused on finding solutions to problems, and one of the problems faced by winemakers is bacteria that can enter the winemaking process and cause wine to spoil, thus reducing its value.
Some types of bacteria, such as Pediococcus sp and lactobacillus sp can create volatile compounds that have a variety of unpleasant consequences, such as giving wine a bitter taste or causing it to have an oily or slimy texture.
Biotechnologists have been finding ways to combat these problems in winemaking. An example is the development of genetically-modified wine.
By transforming yeast with the use of a bacteriocin gene, which is an antimicrobial peptide produced by bacteria, this can kill off bacteria, as the Yeast journal has reported.
Here are other ways in which genetic modification is changing the future of wine.
Boosting The Health Properties Of Wine
A genetic engineering technique called RNA-guided Cas9 nuclease has been found to increase resveratrol levels in wine.
Resveratrol is usually mentioned in health articles because it’s a compound found in red wine that protects the body against disease, but it can also eliminate hangovers.
Researchers from the University of Illinois (via Eureka Alert) have found that using this nuclease to cut copies of a gene in yeast can help them achieve these benefits.
Grapes That Can Fight Mildew
Grapes have three genes that allow mildew spores to attach themselves to the grapes, but researchers from Rutgers University in New Jersey (via USDA) have found that by isolating them and using CRISPR/Cas gene editing techniques to edit the areas where the gene might be present or adding new genes, this could prevent genes that allow mildew from flourishing.
The result?
Healthier grape yields.
Biotechnology Innovations That Are Already Improving Wine
Genetic engineering aside, there are some interesting ways in which biotechnology has already made a huge difference in improving the quality of wine. These include:
The Use Of Methoxypyrazines In Wine Production
Methoxypyrazines are chemicals that can have a massive effect on the quality of wine. Research has found that using the right amount of this chemical can result in a fruity and leafy wine that is clean and crisp, as 1849 Wine reports.
To ensure the perfect amount of methoxypyrazines in wine, wine producers have to ensure the best climatic conditions. Interestingly, this biotechnology has already resulted in delicious wines being produced – it pioneered the 2008 Sauvignon Blanc from McCorquodale in New Zealand.
The Use Of Cold Fermentation
This is a technique involved in making wine that dates back to the 1980s! Scientists discovered that when wine fermentation occurred in ambient temperatures, this resulted in unwanted bacteria that would kill off the yeast. The result?
The wine produced would be too sweet. To prevent this, winemakers would try to control the bacteria with the use of sulphur dioxide, but then the use of stainless steel came along as a way to give winemakers the chance to better control the temperature of the fermentation process.
The result was wine that was more aromatic, fresh, and clean because bacteria was naturally reduced. That’s biotechnology in action!
A Word Of Caution: The Austrian Winemaking Scandal
When it comes to tweaking wine with the goal of improving it, winemakers need to proceed with caution. The 1985 Austrian winemaking scandal is a perfect example of what can go wrong!
What happened was that climate change in the 1980s negatively affected the quality of grapes that were growing.
The wine that resulted from these grapes was sour and lacked taste, so some winemakers tried to find sneaky ways to deal with this problem in order to maintain the previous quality of their wine production.
They used DEG, known as diethylene glycol, in their wines. This is a chemical that’s used in antifreeze products. It’s dangerous and toxic, but the winemakers thought that by putting just a few grams of this ingredient per liter into their wines, it wouldn’t be harmful.
However, this backfired because just 0.1 grams per liter can do major damage to the human body.
The U.S. testing of various wine brands found this ingredient in many of them – 350 Austrian white wines contained the chemical, which was linked to health problems such as liver and kidney conditions, brain damage, and death, although no deaths were reported, as UPI reports.
The Austrian wine scandal has been a warning to other winemakers about the potential dangers involved when experimenting with wine. Even when it comes to techniques such as genetically modifying wine, there are precautions to take.
There is, after all, still much uncertainty about these processes as ideas about genetic engineering still need to change.
Some people are concerned that genetic modifications used in winemaking, such as GM yeast, would be used to correct errors or even mask the incompetence of winemakers instead of being something useful that can improve the process of winemaking, as Food Biotechnology reports.
Moving forward, these are issues that winemakers need to consider.
Related Questions
What is CRISPR?
CRISPR technology allows scientists to edit genomes so that DNA sequences and gene function can be changed. The protein called Cas9, otherwise known as CRISPR-associated, is an enzyme that can cut DNA strands.
Does wine fermentation need no oxygen in order to work?
Contact with air must be prevented to avoid oxidation. When wine is fermented in large containers, the amount of carbon dioxide that’s released is enough to prevent air from entering, as Britannica reports.
Small containers need fermentation traps to prevent air and allow carbon dioxide.
Conclusion
The process of making wine is a fascinating one, but you might not have realized before that it makes use of biotechnology. In this article, we’ve looked at how biotechnology plays an important role in winemaking, as well as the exciting innovations that are in store.
