Penfolds Grandfather Tawny Port 750MlWith each vintage, varietal batches are selected for Grandfather. These batches are individually aged in seasoned old oak casks before being blended together at 14 years of age. This blend is then introduced into the Grandfather Solera. This Solera consists of six stages that are designed to fully integrate all components offering consistency and freshness with a final minimum average blended age of 20 years.