How a South African vineyard is making better wine thanks to cattle and ducks

A historic wine estate near Stellenbosch is turning to cattle, sheep and ducks to improve the quality of its vineyards. Hartenberg Wine Estate says it has become the first in South Africa to earn international certification for regenerative farming, practices that restore soil health and boost biodiversity.

It is not the typical winemaker who herds cattle between his vineyards. Viticulturalist Wilhelm Joubert oversees 80 hectares of vineyard production at Hartenberg Wine Estate, near Stellenbosch. Hartenberg says it became the first vineyard in South Africa to receive Ecological Outcome Verification from the Savory Institute in the US in 2025.

The certification recognizes the farm’s regenerative viticulture practices, which aim to restore and enhance the ecosystem in and around the vineyard.

“The way we are farming, the focus is on soil: to improve soil, and soil is complex. But soil health is part of that. It is to farm in a way that we are actually regenerating our soil by using less input from outside,” Joubert says.

Cattle and sheep for better soil health

One of the regenerative practices here is the cattle that graze cover crops between vineyards.

Their saliva, dung and urine all aid in soil health. Dung beetles are proliferating, spreading the manure deeper into the soil. When cover crops are in full bloom during the wet months, wasps, butterflies, bees and other insects inhabit the vineyards and wetlands.

The farm has not used pesticides or herbicides for two years. Cover crops also help retain water, reducing the need for irrigation.

Sheep further enrich the soil, while runner ducks eat snails and slugs.

A research project at Hartenberg

To address the shortage of scientific data on regenerative viticulture, Stellenbosch University began a three-year study at Hartenberg in 2025. The Regenwine project involves 11 scientists and six students across disciplines including agronomy, animal science, viticulture, oenology, process engineering, agricultural economics and soil science.

One of the researchers, postgraduate student Kaiden Jacobs, is counting species of cover crops. “I think if I look at the project in a broader picture, from what we initially discussed, it’s kind of to see how we can create climate-resilient farming,” Jacobs says.

Viticulture master’s student Dylan Endeacott is also participating in the study, funded by South Africa Wine. He carried out a preliminary study in 2024 at Hartenberg, comparing grape and wine output from cattle-grazed and non-cattle-grazed plots.

“With the study that we saw from last year on the Shiraz block, the control berries were larger than the grazed berries. Smaller berries normally lead to higher quality wines,” Endeacott says. The positive results from grazed vineyards align with the estate’s own data, which was analysed at an independent laboratory.

“We had a very interesting trial comparing a regenerative vineyard with a regenerative vineyard with livestock in it,” says Reynie Oosthuizen, head winemaker at Hartenberg. “We found that the vineyard with livestock had almost 0.5% lower alcohol. The wine had higher anthocyanins and tannins, giving it more structure, but at the same time there was finesse.”

Introducing regenerative viticulture to a wine estate dating back to 1692 shows it is never too late to adapt and innovate.