While the red wines of the Southern Rhône have a relatively smooth transition from one state of maturity to another, the wines of the Northern Rhône experience a bumpier ride.
It’s advisable to open them in one of two windows; either young and fruity, or wait until it has comfortably moved into a mature stage. If you open it between these two windows, you risk finding it closed down and introspective rather than open and giving.
This doesn’t always happen. Sometimes you get lucky (or unlucky – these closed periods can return in waves). Lighter vintages don’t always fall into a hole; the more structured, tannic and long-lasting a vintage, the more likely it is. I also find that wines made with a large proportion of whole bunches are more susceptible.