The 1978 Cuvasion Caberenet Sauvignon is opaque, medium-to-light purple. The nose has some matchstick sulphur on opening and for a good while after opening. Beyond that there are red fruits ripe and tart, gentle black tea flavors, nuances of black earth and cedar, a pleasant CA version of Bordeaux from its day. The taste is of sweet and red fruits and flavors corresponding to the aromas of tea and dark earth. This wine is complete and generous without being strong or demanding, or showing any mid-plate depth or development. Round and generous, unblemished and complete, this wine is well-formed if not particularly stunning. 87 points (remember: that means this is a good wine).
The 1977 Cuvasion Cabernet Sauvignon has a more divided sense of itself. There is no sulphur on the nose, and not the earthy or black tea flavors of the 1978. Instead, there is a mixture of dark fruits, some cooked, and a sense of tension both on the surface and on the finish, which lingers. Not as peaceful as the 1977, there is more depth of character flavor here, but that character is unresolved in a way the 1978 was not. So it is more attention-grabbing but not necessarily better than the 1978. 87 points (remember: that means this is a good wine).
I’ve had both of these within the past decade. I bought them off of a restaurant list. The restaurant bought them on release and stored them at 50 degrees (no, it is not Bern’s). The '77, about 7 years ago, was still quite young and primary. The '78, about 2 years ago, was mature but in no hurry. I rated them both, from memory, in the low 90s, but I may have a more generous scale than you, or may simply have liked them more. I believe the restaurant still has both. I will be there later this winter and will probably have one, and post.
Do you know the provenance of your bottles? I am quite certain that the 50 degree storage had a lot to do with the youth they showed. Cuvaison in the day was among my favorite California Cabs for quality, value, intensity and longevity.
The few 78 cabs I’ve had have been pretty good, considering the age, and likely less than awesome storage. Oldest Cuvaison I’ve had was a 1990 at maybe age 25ish and it was very good.