Negroni, Hernö Juniper Cask. Hernö Juniper Cask Gin, the first gin in the world matured on juniper wood casks, is made from the same distilled gin as Hernö Gin, diluted to 47% ABV and gently matured for 30 days in juniper wood casks. The maturity gives more intense juniper notes finished with a long harmonious hint of citrus peel.