I bought several bottles of Scharzhofberger Fiene Auslese Nikolauswein
1970, Koch, shortly after release and have tasted it over the years. This bottle had no issues and was stored properly. The cork was still holding well, but it had to be mined out in small pieces because it is very fragile in old age.Early on, this wine was somewhat grapefruit-like with considerable mineral character with plenty of acidity somewhat on the harsh side. It was rather sweet and rich, but the sweetness was nearly hidden by the high acidity. Then it fairly soon became dumb and changed little for over two decades. About 10 years ago it slowly started to mature. The wine now is close to the peak, but could improve a bit more. It likely will easily hold to an age of 50 years or more if it is properly stored and the corks hold.
Now you would not know the wine if you had only tasted it young or during the long dumb phase. The color is light lemon. The acidity has now tamed down enough to balance the sweetness and fruit well. There is much fresh pineapple in the bouquet and taste. Also there is some apricot and honey. There is still some mineral character. There is only moderate old Riesling petrol character. The finish is very long.
The grapes for this wine were harvested on December 5/6 1970 which allowed it to be called Nikolauswein and fiene under pre-1971 German wine laws. Unless German wine laws are changed, there will never be another Nikolauswein. Actually there were several other wine names depending on the date of harvest, and very seldom grapes were harvested in January of the next year. Of course, if the grapes had to be harvested before a targeted name day, it might be possible to try for an eiswein if temperature fell low enough.
The risks of making such a "name date" wine were very high. The year usually was fairly cool, but some grapes could ripen to an auslese or higher level if left until December or January. A sudden low temperature could ruin the grapes unless making an eiswein was possible. The grapes could rot. Many wild animals and birds could eat up most of the sweet grapes in a very short time unless they were kept away.