"Room temperature" - is the most frequent and the most common response. But there's a definite caveat ("cabeat"? LOL) to this. In the USA, "room temperature" is typically cons
…idered 72 degrees. This is too warm for virtually any wine. The wine will taste too hot and lose those subtleties of flavor for which Cabernet's are renowned. Worse still, depending on the individual, they may store the wine in an area of the house in which the temperatures rise above 72 degrees, perhaps well above. Higher temperatures can conceivably "cook" the wine, reverting a perfectly delightful wine to grape alcohol. If we think of the typical old world wine cellars where wines were stored, cool (due to the ambient temperature, and due to the "cold" stone walls and dirt floors) cellar-type areas with a fair amount of air circulation (due to the, relatively, poor insulation and construction), we realize that the old term "room temperature" is noticeably cooler than the "room temperature" we now find in modern homes / restaurants that are well insulated against the weather. Therefore, roughly 60 - 65 degrees (63 - 68 is a good range) is more appropriate for hearty wines like the Cabernet's. Of course, some individuals may prefer the Cabernet just a bit cooler, some a bit warmer. Personal taste always takes precedence. But generally speaking, if we stay in that approximate 65 degree "zone", that chosen Cabernet will reveal all it has to offer. Hope this helps a bit. (MORE) 
