Q: I’ve read about a wine fault called ropiness, which seems to be related to lactic acid bacteria spoilage and an elevated concentration of biogenic amines. Are these wines safe to drink?—Susan, Topaz, Calif.
A: Our last two Health Q&As covered the potential health effects of wine flaws, specifically corkiness (a defect caused by TCA) and brettanomyces. Though rare, there are other flaws that can affect wine, including ropiness, which is caused by lactic acid bacteria. These bacteria are also associated with elevated levels of biogenic amines in wine. Wine lovers who come across a flawed bottle might find themselves wondering: Is my wine safe to drink?
What Are Biogenic Amines?
First things first: Biogenic amines are found in many fermented foods and beverages. The ones found in wine are simply amino acid metabolites (these belong to a large class of molecules called amines) produced by certain microorganisms (that is, they’re of biogenic origin). They include tyramine and histamine, and some scientists hypothesize that in sensitive individuals, they may be responsible for negative reactions to wine, including headaches and allergy-like symptoms. Dr. James Osborne, a microbiologist at Oregon State University, told Wine Spectator that these compounds are generally found in “very low levels” in wine—and moreover, that “there’s not been any research connecting [them] to any reactions that people have to wine,” though “the potential exists.”
The majority of biogenic amines in wine are produced by lactic acid bacteria, beneficial strains of which are responsible for malolactic fermentation. This process involves the conversion of tart malic acid into lactic acid, which is softer and rounder on the palate. This change is crucial to the style of most red and many white wines. In that sense, good lactic acid bacteria play a star role in turning grapes into delicious wine.
Why Are Biogenic Amines Produced?
While some lactic acid bacteria are helpful, other strains produce undesirable biogenic amines, particularly in uncontrolled or unsanitary environments. While commercially available malolactic fermentation cultures are screened for these pesky strains, they can find their way into wine in various ways. If these strains of bacteria are present, and particularly if a winemaker forgoes the use of sulfur at certain points during winemaking, they can get out of control. One telltale sign of their negative influence on a wine is a fault called ropiness.
What Is Ropiness?
In extreme cases, and especially in high-pH wines, these lactic acid bacteria can go haywire, leading to a rare flaw known as ropiness. In a ropy wine, lactic acid bacteria produce an excess of long sugars (or polysaccharides), which make the wine thick and gelatinous. This goop can sometimes appear as cloudy “ropes” in the wine. Ropiness is a sure sign that lactic acid bacteria have run amuck during winemaking, and while Dr. Osborne says it likely won’t change the smell or taste of the wine, most people would agree the resulting wine jelly is fairly yucky on the palate.
Are Biogenic Amines and Ropiness Dangerous?
Do either of these related winemaking faults present a health concern? Dr. Gavin Sacks, a food science professor at Cornell University, told Wine Spectator that biogenic amines “can have pathogenic effects, such as vomiting and cardiac disruption, at high concentrations, and their levels are regulated in some countries.” He adds, however, that “these levels are rarely exceeded in commercial wine, and the potential danger from consuming a wine with high levels of biogenic amines is certainly lower than would be experienced with non-alcoholic, high-pH foods”—which carry serious risks, including botulism and listeriosis.
So, while a ropy wine may contain elevated levels of biogenic amines, drinking one is unlikely to cause serious health problems. Moreover, while certain strains of lactic acid bacteria can produce undesirable compounds in wine, they won’t grow uncontrollably in the gastrointestinal tract (like many organisms that cause food poisoning) once the wine has been ingested.
Overall, Dr. Sacks counsels, “I would probably avoid a wine with visible ropiness ... and I suspect many wine consumers would do so, anyway, if only [due to] the ‘ick’ factor.”
Are Bacteria Responsible for Other Wine Flaws?
Another kind of bacteria called acetic acid bacteria can contribute to high levels of volatile acidity (or VA), which can be considered a flaw depending on the severity. Learn more about VA and its potential impacts on health in our next Health Q&A.
In the meantime, and as always, consult your healthcare professional about incorporating wine into a healthy lifestyle.—Kenny Martin
