Inspired by elder bottles of Pewsey Vale Riesling, Yalumba resolved to make an early harvest wine with lower alcohol, a fine balance of natural acids and idyllic levels of residual sugar. Prima is made from grapes picked three to four weeks before the rest of the vineyard. Chosen for their fine citrus flavours, grapes are carefully selected when their natural sugar levels are near 10° Baume. The wine is finished to a semi dry style which retains some of the fruit in balance with chalky mineral acidity, exhibiting purity of style, as it evoves layers of toastyness and spice.

In 1847 Joseph Gilbert planted a single acre of vines, establishing Eden Valley's pioneer sites and one of Australia's first high altitude, cool climate vineyards. Gilbert trialled many different grape varieties at Pewsey Vale, later distributing cuttings to aspiring growers in surrounding areas. Pewsey Vale eventually fell into disuse until 1961, when the estate's proprietor Geoffrey Angas Parsons, paid a visit to his good friend Wyndham Hill Smith at Yalumba with a proposal to restore the ancient Pewsey Vale Vineyard. Prima is bottled to enhance the exotic nature of this wine whilst preserving its pure fruit flavours. The naturally lower alcohol of the wine further heightens its refreshing character.