Do you know what’s really in a bottle of wine? Is wine healthy, or a health hazard? In this series about wine, I will look at how wine has changed from its traditional form into a commercialized product, go through the benefits and risks of wine consumption, and share how to find high-quality wine. This first article will cover a brief history of wine and how wine has evolved into a processed product, not unlike the other processed and refined foods we see today.
Is wine Paleo?
Although some speculate that our Paleolithic ancestors did consume “wine” in the form of fermented fruits, the earliest evidence of wine purposefully made from grapes is from the Neolithic period. A drinking vessel with tartaric acid, which only occurs in large amounts naturally in grapes, was found in an ancient village in Iran, dating from 7,000 years ago. (1) From the southern Caucasus region (which includes modern-day Iran), winemaking traveled to Palestine, Syria, Egypt, Mesopotamia, and then the Mediterranean. (2)
When Rome conquered Greece more than 2,000 years ago, winemaking was one aspect of Greek culture adopted by the Romans. (3) Southern Europe, which contains regions once in the former Roman empire, still consumes plenty of wine, usually with a meal.
In the 18th century, winemaking expanded to South Africa, Australia, and New Zealand. (4) Europeans brought wine to the Americas, first to Mexico and South America. In comparison to this extensive history, the United States’ large-scale vineyards are practically infants, only appearing around 200 years ago.
Do you know what’s in the wine you’re drinking?
What is in a bottle of wine?
Aside from water, a bottle of wine contains hundreds of substances, most of which fall into the categories below.
- Sugar. Glucose and fructose are the principal sugars found in grapes, which are fermented into ethanol during winemaking. What isn’t fermented is called residual sugar.
- Wine yeasts. Naturally found on grapes, yeast is what ferments the grape sugars. Most wines today, however, use added commercial yeast instead.
- Ethanol. Yeasts ferment the sugars into ethanol, generally resulting in an alcohol content of 10 to 13 percent, (2) but this number can be modified by temperature, certain added yeast strains, and added sugar.
- Phenols/polyphenols. Polyphenols affect the appearance, taste, mouth feel, and fragrance of wine. Found in fruits, vegetables, coffee, and tea, polyphenols are most likely responsible for the positive health outcomes associated with moderate wine consumption. They are present in the seeds, skin, and flesh of grapes but are also increased through fermentation and oak aging.
- Methanol. Methanol, a toxic substance, is found in wine in very low levels (0.1–0.2 g/L), (2) but it also occurs naturally in other fruits, vegetables, and their juices.
- Other alcohols, aldehydes, acids. Grape sugars are also metabolized into higher alcohols, esters, and aldehydes, contributing to the overall complex nature of wine.
The stages of winemaking
To understand how wine has evolved over the millennia, an appreciation for the winemaking process is a good place to start. The general steps involved in winemaking are (5):
- Harvesting the grapes
- Stemming and crushing the grapes
- Maceration – Time is given for phenolic components of grapes to be leached from the skin, seeds, and stems into what is called the “must”
- Fermentation – Yeast converts sugar into carbon dioxide and ethanol
- Draining – “Must” is drained without being pressed into barrels
- Thermovinification – Wine may be heated at 50–80°C to improve red wine color
- Clarification and stabilization – This may involve filtration, centrifugation, flotation, refrigeration, and/or pasteurization
- Aging – Wine is transferred to a wooden barrel or metal container
- Bottling – A dose of sulfite is usually added commercially to help preserve the wine
Commercialization changed wine
Everyone’s heard of wine’s supposed health benefits, but not all wine is created equal. Traditionally, wine was made with mashed grapes left to ferment for an extended period of time, resulting in a polyphenol-rich, relatively low-alcohol-containing beverage. Few additional ingredients were added and intervention was minimal. Today, picturing chemists in lab coats is a more accurate portrayal of winemaking than a casually dressed vineyard owner with an oak barrel.
Modern processes have changed wine production. Growing grapes closer together increases vine yields, but this overproduction delays fruit maturity, retains excessive acidity, and is associated with reduced wine quality. (2) To grow grapes in such close proximity, irrigation is almost always required. While this can double fruit yield and increase fruit size, over-irrigation can result in lower sugar and increased grape acidity. (2) Traditionally, a “mild water stress” following grape ripening actually improves grape quality. Unfortunately, many of these traditional methods are lost in today’s wine production.
Wine additives and contaminants
Since wine went commercial, it has evolved into something so different from what it used to be that our bodies no longer handle it well. Today, more than 70 additives are approved in winemaking to increase production, ensure repeatable outcomes, and keep costs low. If you have ever experienced headaches, asthma symptoms, or even diarrhea after enjoying a glass or two of wine, it might actually be due to all that is added to wine rather than the wine itself.
Unlike everything else we eat and drink, nutrition labels and ingredients lists are not required for wine in the United States. Instead of being regulated by the FDA, wine falls under the jurisdiction of the Alcohol and Tobacco Tax and Trade Bureau. As commercial winemakers strive to increase production and lower costs, some questionable and harmful substances have found their way into wine:
Oak chips and sawdust. Those “oak notes” discussed during wine tastings may not actually be the result of oak-aged wine. Commercially, oak chips or sawdust might be used instead to give that oak flavor without the added time of real oak barrel aging.
Fining agents. To remove unwanted substances in wine before bottling, a variety of agents can be used. Many animal-based ones, including egg white, fish bladder, and casein, might surprise many wine-consuming vegans. Bentonite clay is the most common non-animal-based fining agent.
Mega purple. Natural red wine isn’t really supposed to darkly stain your teeth, gums, and clothing. Mega purple, a super concentrated grape juice additive, is to blame. Ten thousand gallons of this sugary concoction are added to 25 million bottles of wine per year. Mega purple, along with another dye, ultra red, are used to produce wine of consistent color.
Sulfur dioxide. Although low levels of sulfites occur naturally in wine as a byproduct of yeast metabolism, commercial winemakers often add sulfite in the form of sulfur dioxide as a preservative and stabilizer. Because a small portion of the population is allergic to sulfites, a wine label must disclose if the sulfite content is more than 10 parts per million (ppm). White wines typically have more sulfites than red wines. Conventional wines can contain up to 350 ppm in the United States, while organic winemakers limit sulfites to 100 ppm.
Histamines. Histamines are found naturally in many foods, including cheese, wine, seafood, processed meats, fermented foods, and eggs. I have talked about histamine intolerance in a previous post and how it is better understood as a component of mast cell activation syndrome. Histamines are produced by immune cells and are responsible for the swelling and redness you see if you get a bee sting. However, some people produce too much histamine and/or are not able to break it down properly. Histamine overload results in sneezing, headache, diarrhea, skin itchiness, and shortness of breath.
The histamine content of wine varies widely, depending on grapes used, ethanol content, sulfite content, and more. (9, 10, 11) The commercialization of wine may have increased histamine content. Fertilizing grape vines increases the histamine content of wines, (12) and organic wines have lower levels of histamine. (13)
Commercial yeasts. Before 1974, all wines were fermented with their naturally occurring yeasts, but most today in the United States are not. Winemakers instead opt for commercial yeasts to better control the fermentation process for a more reproducible product. Many of these added yeasts are genetically modified. Histamine-sensitive individuals may experience headaches after wine fermented with commercial yeasts, as some bacterial cultures produce more histamine than others. (14)
Sugar. In winemaking, yeasts ferment the sugar found naturally in grapes. Wine is “dry” when the yeasts fully ferment all the sugar into alcohol. Winemakers sometimes will add additional sugar before fermentation to increase the alcohol content or flavor. Residual sugars in wine can be masked by tannins and acidity, so you can’t always tell by the taste of wine how much sugar is present.
Pesticides/herbicides/fungicides. Just as in produce, organic wine exposes you to fewer pesticides, herbicides, and fungicides. In a study of French wines, only 10 percent were free of pesticide and fungicide traces. Vineyards are only 20 percent of produce volume in France but use 80 percent of the nation’s fungicide. In the United States, Monsanto’s Roundup is the most commonly used herbicide in vineyards. Some of these compounds are linked to cancer and can disrupt hormone function, which I have covered in depth in articles on organic produce and environmental toxins.
Arsenic. Looks like rice may not be the only food with arsenic concerns. The Environmental Protection Agency’s water standard for arsenic is less than 10 parts per billion (ppb). A few years ago, a class action lawsuit was filed against several winemakers for having up to five times the arsenic level acceptable for water in their wines. Included wines were varieties of Trader Joe’s infamous Two-Buck Chuck and some types of Franzia. Although the lawsuit was dropped for a couple of reasons, I would still steer clear of cheaply made wine.
Phthalates. Phthalates are endocrine disruptors linked to cancer and fertility issues. (15, 16) They are common in cosmetics and plastics, but a study of French wines found dibutyl phthalate in almost two-thirds of the wines tested. (17) Only 17 percent of the samples didn’t contain one of the three phthalates tested.
Mycotoxins. Mycotoxins are toxic substances produced by fungi and are linked to diabetes, obesity, and kidney disease. (18) Unfortunately, mycotoxins are widespread in wine and in other processed foods like grains. One study found a certain mycotoxin called fumonisin B(2) in 23 percent of wines tested from 13 countries. (19)
That’s quite an intimidating list! Can the health-boosting polyphenols in wine outweigh these dangerous additives? In the second article of this series, I will go through the health benefits and risks of wine consumption to determine if drinking wine can actually be good for you.
Now I’d like to hear from you. Do you suffer ill effects after enjoying a glass or two of wine? Were you aware of the additives and contaminants often found in table wine? Let us know in the comments!