In the second half of the 20th century, Italy decided to establish a series of laws to safeguard the quality and authenticity of their wine.
These safeguards take the form of protected zones where growers and producers must adhere to strict regulations in order to be certified by these laws. The laws also govern things like the type of grapes used, the alcohol content, and how long the wine is aged.
Certification falls into three categories of decreasing strictness: DOCG, DOC, and IGT.
Denominazione di Origine Controllata e Garantita (DOCG): Seeing this on the label of your wine bottle means that the wine producers followed the strictest regulations possible to make that wine. The wine was tested a committee that then guarantees the geographic authenticity of the wine and its quality. There are currently only a handful of Italian wines that qualify for DOCG status.
Denominazione di Origine Controllata (DOC): DOC wines are much more commonly found. The rules governing quality and authenticity are still very strict, but they're a little more generous than those for DOCG status. For instance, the geographic zone might be a little bigger or the rules about what kind of grapes might be a little more relaxed.
Indicazione Geografica Tipica (IGT): This designation was created a little after the DOC and DOCG designations in order to accommodate growers who couldn't meet all the DOC or DOCG regulations for one reason or another, but were still producing great wines.
As you might imagine, there is a correspondence between the designation of a particular wine and its cost in the store! Also, don't automatically assume that a DOC wine is better than an IGT wine--some great wines can sneak in under the radar.
(Image: Emma Christensen for the Kitchn)