The private wine industry at that time was almost non-existent, but Andries was determined to make high-quality wine. By the 1940s he was shipping respectable quantities of wine in bulk to London. Big wooden vats were sent out to the Cape from Europe by sea and then on to Tulbagh by rail where they were filled with wine and sent back the same way.

In 1948, the estate launched a Riesling (Cape Riesling) which two years later was awarded a gold medal at the Commonwealth Wine Show in London. Theuniskraal Cape Riesling has to this day a great following. The acclaimed Theuniskraal range further includes Theuniskraal Sémillon/Chardonnay, an unwooded fruity blend of Sémillon and Chardonnay, Theuniskraal Sauvignon blanc, Theuniskraal Prestige, a blend of Cabernet Sauvignon and Shiraz, Theuniskraal Shiraz, Theuniskraal Cabernet Sauvignon, Theuniskraal Bouquet Blanc, a sweet white blend of Gewürztraminer and Muscat Blanc and Theuniskraal Moscato Rosé, a semi-sweet rosé made of Muscat Ottonel and Shiraz.