The Grapes

Riesling vines are tough.  They thrive in cold climates, on steep hillsides, and in marginal soil.  The green-skinned grapes ripen later than many other varieties, and sometimes are left hanging on the vine to produce sweet late harvest wines or even ice wines when the grapes actually freeze on the vines.  Great wines are made in the vineyard, so the key is for winemakers to harvest the grapes at the optimal balance of natural sugar, acid and pH.