In these pages, I have avoided references to the Italian wine classification system because it involves a lot of detail, and regardless of adherence to the rules that the system dictates, a good wine is a good wine.
California is without such a classification scheme, and most people have no objection to its absence. They have a basic understanding that they will get a good Cabernet from Napa or Sonoma, a pleasant Syrah from Paso Robles, or a fine Zinfandel from the Sierra Foothills. Of course, sometimes you win, and sometimes you loose.
Ultimately, a wine classification system provides not only additional information about what the bottle contains but also valuable consumer protection.
So briefly, here is the Italian system, made simpler in 2011 when the EU standardized wine classification for member states. The regulations define best practice or the lack thereof in particular categories.
The EU established four categories of wine, Vini (basically generic wines), Vini Varietali (Varietal Wines), Vini IGP (Wines with Protected Geographical Indication), and Vini DOP (Wines with Protected Designation of Origin). The first two categories refer basically to generic wines, and whose grapes can come from anywhere in the EU, and whose labels are not allowed to specify country of origin. So we can forget those and hope to always drink better.
The next category is IGP, in Italy called IGT (Typical Geographical Indication), which includes a previously separate category, Vino da Tavola, no longer legally viable. So IGT designates wines produced in a specific area of Italy. Regulations authorize certain grape varieties, vineyard and winemaking practices, taste requirements, and labeling regulations. In other words, if you buy an IGT wine from a winery in Chianti, Tuscany, you can be certain that the grapes come from there, not from some place in Calabria.
While these are normally modest wines without stringent regulations, they can occasionally be special and especially expensive because less restrictive IGT rules can accommodate successfully innovative winemakers, who wish to make wines other than those that are typical in their regions. The fourth category is DOP and includes two Italian sub categories, Vini DOC (Controlled Destination of Origin and Vini DOCG (Controlled and Guaranteed Designation of Origin).
DOC wines must have previously been IGT wines for five years and normally come from smaller appellations that are known for special climatic and geographical conditions, which imbue the wines with special characteristics. Viticulture, winemaking, and aging requirements are stricter than those in the IGT category.
DOCG wines, some of Italy’s finest, are subject to the most rigorous standards of all and are eligible for promotion after having had DOC status for ten years. In addition, DOCG wines are guaranteed and must be submitted to a tasting panel. They are usually wines that have already enjoyed elevated commercial success
So long story short, if you see a DOCG wine for a comfortable price, are you going to buy it without knowing anything more? Absolutely!