Koerner operates in Clare Valley, South Australia's premier cool-climate region in the Mount Lofty Ranges. The winery focuses on Riesling, the varietal that defines Clare Valley's character—mineral-driven, high-acid wines with citrus and stone-fruit precision. Gullyview Vineyard Riesling and Parish Vineyard Riesling anchor the portfolio, both rated by Wine Advocate, Wine Enthusiast, Decanter, and Wine Spectator. The winery also produces Tiver Vivian Vineyard Rosé from Sciacarello, a Corsican variety that brings aromatic complexity and dry structure to the range. Clare Valley's continental climate and slate-rich soils create the conditions for wines of clarity and aging potential—characteristics evident across Koerner's offerings.