Riesling has long been an insider’s favorite among sommeliers and consumers in the know. It is considered one of the best values—across sweetness levels and production areas—and pairs well with a wide range of foods. Many in the business who saw the Moscato craze take off a few years ago had high hopes that some of that fever would rub off on Riesling, but the wine’s fans seem to be a different consumer base. Many less-knowledgeable drinkers still have a hard time determi...