Birchwood operates in Langhorne Creek, a subregion of the Fleurieu Peninsula in South Australia known for producing structured red wines from warm, maritime-influenced vineyards. The winery's portfolio centers on Shiraz and Cabernet Sauvignon, varieties that thrive in the region's conditions. The Decades Shiraz, rated 89.0 by prestige critics including Wine Advocate and Wine Spectator, represents the winery's work with the region's signature varietal. Twin Rivers Cabernet Sauvignon, rated 85.8 by the same critics, demonstrates the winery's range across Langhorne Creek's primary red grapes. Both wines have been assessed by major wine publications, anchoring Birchwood's output in the broader South Australian tradition of bold, fruit-forward reds.