Preventing Re-fermentation in Dealcoholized Wine During Bulk Shipping

Preventing Re-Fermentation during Bulk Shipping

Fully dealcoholized dry wine (≤0.5% ABV, with minimal residual sugar) is more vulnerable to spoilage than standard wine because it lacks alcohol’s preservative effect. When shipping such wine in bulk (e.g. flexitank bladders inside containers), it’s critical to manage re-fermentation risk. Below we examine whether re-fermentation can occur in a dry, 0.5% ABV wine, which microbes might be responsible, how shipping conditions affect this risk, and best practices (sanitation, temperature control, oxygen exclusion, and stabilizing treatments) to prevent any unintended fermentation. Practical recommendations and industry guidelines are provided throughout.

Re-fermentation Risks in Dealcoholized Dry Wine

Can “re-fermentation” happen in a fully dry, dealcoholized wine? In general, true alcoholic re-fermentation is unlikely if virtually all fermentable sugars are gone. However, microbial spoilage can still occur – certain yeasts and bacteria can metabolize other traces in the wine, producing gas or off-flavors. In essence, while a vigorous sugar-driven fermentation is improbable in a dry wine, slow secondary fermentations or spoilage activity by microbes are possible if they gain a foothold. Key points include:

• Loss of Alcohol’s Protection: Ethanol is a natural antimicrobial in wine. Removing it “diminishes the preservative impact” and leaves dealcoholized wine more prone to microbial growth. Even with no sugar, a 0.5% ABV wine behaves more like a perishable beverage (similar to juice) in terms of microbiological stability.

• Spoilage Yeasts (Brettanomyces & others): Brettanomyces bruxellensis (“Brett”) is a notorious wine spoilage yeast that thrives on slim pickings. Brett can metabolize the tiny amount of sugar in “dry” wines, and even use alternative substrates like ethanol, acetic acid, or cellulose for growth. In a dealcoholized wine, Brett faces almost no alcohol inhibition, so if present it can slowly grow and produce volatile phenols (barnyard, band-aid aromas) and even acetic acid (volatile acidity). Thus, Brettanomyces contamination is a serious risk – it won’t create a fizzy ferment, but it can spoil the wine’s aroma and flavor over time.

  Other wild yeasts can also cause trouble. For example, Saccharomyces cerevisiae (the usual fermenting yeast) or oxidative yeasts like Rhodotorula have been identified as “native spoilage yeasts” in dealcoholized wine. If any viable Saccharomyces cells remain or get in, they could slowly ferment even minute residual sugars (or glycosides), potentially generating a bit of CO₂ and sediment. Rhodotorula (a wild yeast) doesn’t ferment much sugar but can form haze or film and produce off-colors/pigments. A study on dealcoholized red wine found both Rhodotorula mucilaginosa and S. cerevisiae were able to grow in 0.5% ABV wine unless inhibited by preservatives. This shows that yeast activity is possible in dealcoholized wines if microbes are not completely removed or suppressed.

• Lactic Acid Bacteria (LAB): Wines that did not undergo malolactic fermentation (MLF) may still contain malic acid, which certain LAB (like Oenococcus oeni or Lactobacillus) can ferment into lactic acid and CO₂. This spontaneous malolactic fermentation is a form of re-fermentation often seen as “spring/summer refermentation” in bottles. In a sealed flexitank, MLF would release CO₂ gas, possibly causing swelling pressure, and it changes the wine’s acidity and flavor (adding diacetyl “buttery” notes or haze). Even if malic acid is low, some hetero-fermentative LAB can metabolize trace sugars or other compounds, producing volatile acidity (acetic acid) and off-odors. LAB contamination is thus a risk – they can cloud the wine, generate CO₂, or create spoilage byproducts. For example, if potassium sorbate is used as a preservative, any surviving LAB can convert it to geranium-smelling compounds, ruining the wine. Keeping LAB out or inhibited is crucial.

• Acetic Acid Bacteria: Acetobacter and Gluconobacter (acetic acid bacteria) won’t ferment sugar into alcohol; instead they oxidize ethanol into vinegar (acetic acid). In a 0.5% ABV wine, there is only a little ethanol to feed them, but given oxygen they can raise volatile acidity quickly. These bacteria are strictly aerobic – they require oxygen – so they’re mainly a risk if the wine is exposed to air during transit. If contamination occurs (e.g. via air leak or unsterile container), even the small 0.5% ethanol can be turned into acetic acid, spoiling the wine’s aroma and taste. While this isn’t “fermentation” per se (it’s oxidation), it’s a microbial spoilage to guard against in bulk shipping.

Bottom line: Yes, re-fermentation or microbial spoilage is possible in a fully dealcoholized dry wine if viable microbes are present. The most likely culprits are spoilage yeasts (like Brettanomyces or wild Saccharomyces) and bacteria (lactic acid bacteria, or acetic bacteria if oxygen intrudes). These organisms can proliferate under the right conditions and cause haze, CO₂ production, volatile acidity, and off-odors – effectively ruining the wine’s quality and commercial value. Therefore, even “dry” non-alcoholic wine must be treated as microbiologically delicate; preventing any microbial growth is paramount.

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Sources:

• Bartowsky, E. (2009). Wine spoilage organisms and wine stability.

• Sánchez-Rubio, M. et al. (2017). Control of native spoilage yeast on dealcoholized red wine by preservatives – J. Food Sci. 82(9): 2128-2133.

• Longo, E. et al. (2025). Dealcoholized wine: Techniques, stability, and perspectives – Compr. Rev. Food Sci. Food Saf. 24(3).

• Palate Press (Erika Szymanski, 2013). “Meet Brett: Why You Do or Don’t Want It In Your Wine”.

• OIV (2015). Good Practices Guide for Bulk Wine Transportation – International Code of Oenological Practices.

• BevZero (2021). “The Do’s and Don’ts of Making Non-Alcoholic Wines” – BevZero Blog.

• Smithsonian Magazine (2022). “The Science Behind Nonalcoholic Wine”.

• Kan-Haul (2022). “Flexitanks for Wine Transportation”.