What additives are actually in your wine?

It’s become a hot – and often misunderstood – topic, with conflicting reports about what goes into most wines, why, and what is actually permitted. Simon J Woolf explains all…

Words by Simon J Woolf

“Clean wine” is the wellness industry’s latest obsession, though it's unclear what the tag actually means

Just as drinkers had started to get their heads around natural wine, so a new sub-genre has appeared. “Clean wine” is the wellness industry’s latest obsession, with brands such as Cameron Diaz and Katherine Power’s Avaline – whose third wine, a red of as-yet unspecified provenance and grape variety has just been launched – promising “clean, vegan wine without all the extras.”

The natural wine movement evolved around artisan winemakers seeking greater terroir expression, through minimal intervention and a return to older traditions in place of technology. Provenance and organic farming are key components. Clean wine, in contrast, is a heavily marketed and questionable premise, as exposed by Felicity Carter in the Guardian. Clean wine brands promise wines with less sugar and “no additives”, but are often vague when it comes to sourcing, farming practices and vinification methods.

So what are all these “extras” that Diaz and Power disparage? Which additives are commonly used in most wines, and why? Are they actually bad for us, and can winemakers do without them?

Wine producers are not required to list ingredients on a wine’s label, despite the fact that around 70 different substances can legally be used in its production. These include everything from powdered tannins and oak chips, to copper sulphate, polyvinylpolypyrrolidone or pine resin. Since these are winery-based additions, nearly all of these are also legitimate in organic wines, a certification which deals largely with vineyard practices (hence any list of additives does not take account of pesticides and herbicides, which shouldn’t, ultimately, find their way into the cellar). Here are some of the most common, and the rationale behind them:

Cameron Diaz sharing a glass of wine with a friend
Cameron Diaz and Katherine Power’s Avaline brand promises “clean, vegan wine without all the extras”

Fermentation to order

Most commercially produced wines are fermented with ‘selected yeasts’ – yeast strains isolated in a laboratory, and then sold in packages for winemakers to inoculate their tanks. Selected yeasts are optimised to ferment grape must quickly and efficiently, ensuring that wines reach the desired level of dryness. A vast range includes neutral strains, options designed to emphasise specific aromatic or flavour profiles, and yeasts for specific grape varieties.

Yeasts die once they run out of sugar to ferment – or once the alcohol level gets too high. Remaining yeast cells are typically filtered out before bottling. Even where they remain, in unfiltered wines, they pose no health risk.

The case against selected yeasts is that they homogenise wine. Natural wine producers view the ambient yeast populations in the environment and on the skins of grapes as an essential part of vintage character. The wild yeast fermentations they often prefer can be slower and less predictable, but because a greater variety of yeast families and strains are involved, the character of the resulting wine is often more complex and nuanced.

Some “clean wine” brands have admitted that they use selected yeasts.

Feed me

A range of  yeast ‘accessories’ include enzymes and yeast nutrients (eg: Diammonium Phosphate or DAP). They ensure that yeasts work quickly and reliably, avoiding stuck fermentations or the production of stinky hydrogen sulphide compounds. These products are focused on mass-production wines destined to be piled high on supermarket shelves. They are unlikely to be used by artisanal winemakers. As with yeasts, enzymes and nutrients are consumed during fermentation, leaving no trace in the finished wine.

Sweet as sugar

Chaptalisation, or increasing the potential alcohol level by adding additional sugars before fermentation, has been popular in winemaking for well over a century. The aim is not to produce a sweet wine, but to increase fermentable sugars so that the alcohol reaches a desired level. Chaptalisation is forbidden in top-tier wine classifications such as Italian DOCs or French grands and premiers crus.

Although cane or beet sugar are allowed, many wineries prefer rectified or concentrated grape must. As these are produced from raw grapes, they are not technically classed as additives.

The claims of clean wine brands that chaptalised wines contain excessive sugar are nonsensical, as any added sugars are converted into alcohol. That said, some major brands such as Apothic are deliberately produced to have a high amount of residual (unfermented) sugar, and marketed to sweeter-toothed consumers.

Chaptalisation is nowadays regarded as anathema to the idea of artisan wine – although classic Bordeaux and Burgundy wines were routinely chaptalised in the past. Ever-warmer vintages and better vineyard management techniques have also largely alleviated the need.

Vinification techniques and practices in the winery – not the vineyard – dictate what additives are used in the winemaking process. Photo by Jon Wyand

Acid freaks

If a vintage is overripe and the grapes lack sufficient natural acidity, it’s legal in some regions and classifications to acidify with tartaric or malic acid. Conversely, grape must can also be de-acidified, using calcium carbonate or potassium carbonate. Such issues tend to concern wineries working with bought-in grapes or massive quantities, where quality control is harder to monitor. Care has to be taken with these measures, as the resulting wines can feel manipulated. However, apart from the drinker’s disappointment, there are no health risks.

A vegan’s nightmare?

Most commercially available wines are filtered and fined, to ensure they are attractively star-bright, with no solid particles, tartrate crystals or dead flies in the bottle. Vegans insist that if egg whites (albumen) or fish glue are used for fining (both are common), the wine cannot be vegan – never mind that the substance does not remain in the wine and is merely used as a coagulant to remove proteins and colloids that could cause the wine to become hazy.

Other substances in common use include bentonite (for fining) or kieselguhr clay (for filtration). Again, these substances do not remain in the wine.

The big headache

The additive that really stirs up hornet’s nests is sulphites. Sulphur dioxide (SO2) in various forms is used at many stages of winemaking (pre-fermentation, racking, bottling) to prevent oxidation, kill unwanted bacterias and stabilise the wine. Dry wines sold within the EU may contain a maximum of between 100–170 mg/L total sulphites, depending on whether they are white, red, organically or biodynamically certified. In many cases, winemakers use significantly less than these amounts.

Sulphur dioxide is also produced naturally by fermentation, and even a wine made with no added sulphites can reach levels of 30mg/L or more. All wines with over 10mg/L of total sulphites must state “contains sulphites” on their labels in the US and EU, hence this wording is standard even for natural wines made without any additions.

Making wine without added sulphites is a risky business, requiring perfectly healthy grapes and a fanatical approach to hygiene. Nonetheless, increasing numbers of natural winemakers believe it is worth the risk, as sulphites can reduce a wine’s expressiveness, turning it into a static snapshot rather than a living organism.

Claims are often made that sulphites in wine cause headaches and allergic reactions. In reality, less than 1% of the world’s population are estimated to have a sulphur allergy. The legal maximum levels for sulphites in wines are very low compared to other beverages and foodstuffs. Dried apricots, for example, can contain levels 100 times higher than wine. On the other hand, all wines – whether clean, natural or mass-market – contain alcohol, a substance which gives you a headache if you drink too much. It’s that simple.