Pinking arrives without much warning. During fermentation and ageing, the wine may behave exactly as expected: pale and innocent. Then, once the wine is already in the bottle, a salmon-red or pinkish colour appears. It may be subtle, but it’s enough to raise eyebrows, because appearance matters. And “pinkish” is not what consumers expect from a white wine.

The unwelcome rosé impersonator

Pinking refers to the appearance of salmon or pink tones in white wines made from white grape varieties. It has been reported worldwide in cultivars such as Chardonnay, Chenin blanc, Sauvignon blanc, Sémillon, Pinot gris, Riesling and others. Its unfortunate timing is one of the reasons it is so frustrating. In most cases, the wine is already bottled by the time the colour change becomes visible. Occasionally, it appears earlier, while the wine is still in the tank, but this is less common.

Looks suspicious, tastes innocent

Despite the colour change, the taste usually remains unaffected. The aroma, however, may lose some freshness. This suggests that other oxidative reactions may have also joined the party. And this is where the story becomes more complex.

A winemaking paradox

The exact mechanism behind pinking is still not fully understood. What is clear is that it is linked to oxidative reactions, most likely involving phenolic compounds. Phenolic compounds are present in all white wines to some extent. Yet not all white wines respond in the same way. Some remain stable, while others develop the characteristic salmon-pink tone.

One important observation is that pinking often occurs in wines produced under reductive or hyper-reductive conditions. These conditions are very useful for producing sought-after fresh, aromatic wines, particularly those with varietal thiols and delicate ester aromas. However, reductive winemaking can also leave certain phenolic compounds largely untouched. When the wine is then exposed to oxygen somewhere down the production line, even in small amounts, these compounds can react, contributing to the salmon-pink colour. Hence, the winemaking paradox.

Some wines are more at risk

Not all wines carry the same risk. Sauvignon blanc is often described as particularly vulnerable. Vintage also plays a role, which points back to grape composition at harvest. Ripeness is another factor to consider. As grapes become riper, phenolic extractability tends to increase.

Processing choices also add to the picture. Whole-bunch pressing can introduce additional phenolic compounds from the stems. Cold handling of must can increase dissolved oxygen levels, and as mentioned earlier, reductive winemaking can help protect aroma, but it may also allow reactive compounds to remain in the wine.

Higher pH adds another concern. As pH increases, the proportion of molecular SO2 decreases, which weakens the wine’s protection against oxidation.

Individually, these factors may not cause pinking. Together, they can create the right conditions for the colour shift to appear later. Susceptibility is therefore shaped by a mix of vineyard conditions and cellar decisions.

Reducing the risk

Because pinking often appears only after bottling, prevention needs to begin much earlier. The aim is to reduce the pool of reactive phenolic compounds before they become a problem. LAFFORT® products such as POLYMUST™ ROSÉ, which contains PVPP, and OENOFINE™ PINK, a PVPP alternative, can be useful. Applied during juice clarification or fermentation, they help reduce compounds that may later contribute to pinking. This is particularly relevant when grapes are riper or when whole-bunch pressing is used.

If neither PVPP nor carbon is your thing, OENOFINE™ NATURE may also be considered to reduce the risk of pinking. However, a high dose may be required, and the risk may not be eliminated entirely.

Oxygen, the unwanted hitchhiker

After fermentation, the focus shifts to protection. Once the wine is off its lees, maintaining adequate free SO2 is essential. SO2 provides some protection against pinking, but it must be maintained consistently, especially during transfers and handling. Every movement of the wine carries a risk of oxygen pick-up. Careful handling, combined with good cellar practices, helps keep dissolved oxygen levels low. Before bottling, sparging offers a final opportunity to remove oxygen and reduce the risk of later reactions.

A word of caution on ascorbic acid

Some producers choose to add ascorbic acid just before bottling. It can be effective, but only when used correctly. Without sufficient SO2 already present, ascorbic acid can have the opposite effect, accelerating oxidation.

What to do when the pink alarm goes off

But what if no precautions were taken and a pre-bottling pinking test showed susceptibility? Or worse, what if the wine has already started to turn pink? Corrective action is still possible, provided the wine has not yet been bottled. PVPP (VINICLAR™ P) or a PVPP alternative formulation, such as OENOFINE™ PINK, offers a targeted fining approach to remove the compounds responsible for the pink colour. Applied to finished wine, it can help restore visual quality before bottling.

A shift in thinking can prevent a shift to pinking

Managing pinking requires a shift in thinking. It is not only about reacting to what is visible. It is about anticipating what may happen later. Decisions made during pressing, clarification, handling and before bottling all contribute to the outcome. In the end, the difference between a stable white wine and one that develops a salmon-pink hue often lies in a series of small, cumulative choices.

References

  1. Ask the AWRI: Not so pretty in pink. Grapegrower and Winemaker August 2016, Issue 631
  2. AWRI Frequently Asked Questions: Pinking https://www.awri.com.au/industry_support/winemaking_resources/frequently_asked_questions/pinking/
  3. Coetzee, C., 2019. Should we be afraid of pinking? Sauvignon blanc South Africa. https://sauvignonblanc.com/should-we-be-afraid-of-pinking/
  4. Filipe-Ribeiro, L., Andrea-Silva, J., Cosme, F. & Nunes, F.M., 2022. Pinking. In: White Wine Technology, Chapter 15, Pages 187 - 195. https://www.sciencedirect.com/science/chapter/edited-volume/pii/B9780128234976000247
  5. Nel, A.P., Du Toit, W.J. & Van Jaarsveld, F.P., 2020. Pinking in white wines: A Review. Afr. J. Enol. Vitic., Vol. 41(2). https://www.sasev.org/journal-entry/pinking-in-white-wines-a-review/

For more information, contact Karien O’Kennedy at [email protected].

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