It seems to me that there are several aspects that influence the age at which any wine will reach its peak: the number of years it has been in the bottle being the most obvious, but also factors such as the conditions it has been stored under, the vineyard it was grown in, and the characteristics of that particular vintage. The time of bottling and the length of time the wine was left on the lees (the dead yeast cells) also play an important role. All play a part in determining when a wine will be at it's best, and of course one must consider personal preferences - do you prefer wine that is young, fresh, and lively, or wine that is 'harmonious', with less complexity? Up to a point, it seems that probably the least reliable indicator is the number of years it has spent in the bottle....

First, the time of bottling. I am hardly alone in noticing variation between cases of the same wine, or even from one bottle to the next, and while storage conditions certainly play a part, by far the likliest factor is the time the wine was bottled. Most of the wineries in Germany are pretty small, and very few if any of the smaller ones can afford modern high-speed bottling lines. Since the terms 'Gutsabfüllung' and the older 'Erzeugerabfüllung' both carry considerable prestige, most German winemakers strive hard to do the bottling themselves, which is not, in my opinion, always a good thing. Even a small winery of say 3-5 hectares will produce 2000-5000 cases of wine each year, and on a manually operated bottling line that will take several months to bottle an entire year's harvest, even working eight hours a day, five or six days a week, and that difference in bottling time can have significant effect on the wine. Generally speaking, wines bottled earlier will be fresher, fruitier, with a greater fruity complexity. The same wine bottled a few months later will have less complexity of fruit, a somewhat softer, slightly drier acidity, and somewhat less elegance. The difference is likely to be more noticeable in years of fruity wines with high acidity.

Secondly, the time the wine has been in the bottle: storage conditions play a large part in this, as does the characteristics of the vintage and the vineyard the wine was grown in, but here goes.... generally Mosel wines are fast to mature, and are often ready to drink when they are bottled. Despite this, many will last for, and even improve for many years. Personal preferences play a huge part (I will willingly admit to liking the 'fresh and fruity' style of wine), but some wines remain 'closed' on both the nose and the palate for many years, eventually emerging to become a very fine wine indeed for those who have the patience. The characteristics of the vineyard also play a massive role: Ürziger Würzgarten wines are very slow to mature, probably largely due to the iron in the soil, and can take several decades to reach maturity, especially for wines such as Eiswein, whereas the wines of Zeltingen, just a walk away, are far faster to both mature and die. Vintages with highish acidity will in general both be slower to mature, and longer lived, especially in those few years that give wines with both high acidity and considerable ripeness, but this in part depends on the nature of the acidity: sharper, grapefruity acidity will take longer and live longer than softer, rounder acidity. In turn this is in part due to the way the wines were vinified and matured: oak or stainless steel. Oak barrels seem to tend to give wine with softer acidity, whereas stainless steel seems to give sharper acidity and greater complexity of fruit. Despite this, wine vinified in oak sometimes seems to have a longer life than wine vinified in stainless steel. Go figure...

Finally storage conditions.... NEVER keep wine bottles standing upright for long periods of time. If the cork dries out, air will get in, wine will probably leak out, and the wine will 'age' rapidly, not always in the most pleasant manner. It may become oxidised and undrinkable. Avoid extremes of temperature, and keep the bottles in the dark. The ideal temperature is a more or less constant 10 C, though few people can manage this without specialist wine fridges. Avoid anything above 35 C or below 2-3 C, and especially large sudden temperature swings. That's about it.