Minimal intervention winemaking is the practice of making wine in the most natural way possible, without pesticides, chemicals or unnecessary additives.

In order to mass produce wine, a vineyard would typically grow and harvest the maximum amount of grapes possible. That means growing more than 12kg of grapes per vine, resulting in an output of around 10 bottles of wine from each individual plant.

Vineyards focused on quality on the other hand, carefully grow at lot less grapes and eventually harvest only around 1kg of grapes from each vine. Which means no more than 1 bottle of wine from each vine.

When a vineyard focuses on quantity, they will be utilising a significant amount of pesticides and anti-fungal treatments to ensure maximum yields, especially in climates with harvest-time humidity and problem diseases such as mildew.

The Role of Sulphites

The most common additive is sulphite (or sulfite), an inclusive term for a preservative that’s widely used in winemaking, as well as across the food industry in general.

Sulphite-free wines refer to a style of winemaking where no additional sulphites have been added during the winemaking process, and technically these are termed as “No Added Sulphite” or “Natural Wines”.

Sulphites (or SO2) are used primarily as an antioxidant and antibacterial additive.The amount of sulphites that a wine can contain is highly regulated around the world. Any wine containing more than 10 mg/l (or ppm, parts per million) of sulphites must include text on the wine label that references the words ‘contains sulphites’.

Sulphites play an important role in preventing oxidization and maintaining a wine’s freshness, and since the winemaker has very little control over the wine’s storage conditions from the time the wine leaves his winery, SO2 is almost always a necessity used to help guarantee that the bottle of wine you open will be in the exact condition the winemaker intended.

The maximum levels allowed by the EU are 150 mg/l in dry reds, 200 mg/l in dry whites and rosés, 235 mg/l in sparkling wines, and 250 mg/l in sweet white and rosé wines.

Maximum levels for dry wines outside Europe are generally 350 mg/l in the US, 300 mg/l in Chile, 250 mg/l in Australia, 130-180 mg/l in Argentina and 150-160 mg/l in South Africa.

Considering that dried fruits can have levels equivalent to 1000 mg/l, if you regularly eat dried fruit without any adverse reactions, then you are probably not allergic to sulphites.

Are Organic Wines Lower in Sulphites?

Many wine producing countries (USA, Chile, Australia, South Africa) have already established standards for organic wines, and the EU has also standardised legislation with regard to the organic winemaking. Organic wine must of course be produced using organic grapes, however Sulphites can also be added, but at a much lower level than regular wine. The new EU approved ranges for S02 content in organic wines must be: less than 100 mg/l for dry reds, 150 mg/l for whites and rosés, and 220 mg/l for most sweet wines.

Additionally in the US you will find more wines labeled ‘made from organically grown grapes’ as opposed to labeled as true ‘organic wine’, because in the US ‘organic wine’ must not have any added SO2.

Are Sulphite-Free Wines Better?

In reality, totally 100% sulphite-free wines do not exist. There are always a tiny quantity of naturally occurring sulphites in every wine resulting from the yeast metabolism during fermentation. However, the levels are very low and they are harmless, and usually under a level of 10 mg/l.

“Sulphite-Free” wine is more of a marketing gimmick, as the naturally occurring sulphites would have to be removed using a chemical extraction process, and the wine would no longer be a “natural wine”.

Red wines without any SO2 will usually have a much shorter shelf life and need to be kept in perfect cool storage conditions. White wines are even more prone to oxidation and the development of aldehyde off-odours, so adding SO2 is particularly important, and for this reason white wine will usually contain much more Sulphites than red.


On your Ronda Wine Tour, you will taste at wineries that use the minimum of sulphites (usually around 20-40 mg/l) and even produce “No Added Sulphite” wines (less than 10 mg/l).