Syrah Grapes On The Vine - Wine-making Grapes, Like These Syrah (or Shiraz) Grapes, Require Different Growing Conditions Than Grapes Meant For Eating. Cultivating Wine Grapes Involves Trying To Concentrate Sugars And Encourage Thicker Skins, Because These Are What Give Wine Its Flavor. To Do That, One Of The Most Important Factors To Look For Is The Drainage Of The Soils. These Grapes Are Grown On A Greenstone Schist Formation In Westminster, Maryland. Photo Credit: Alex Demas, USGS. Watch A Video About "The Science Of Good Taste — Geology, Food, And Wine" At On.doi.gov/FoodWine You Can Also Learn More About "Oktoberfest! The Science Of Beer And Wine Making" At On.doi.gov/Oktoberfest Photo