Germans have long fermentations

It seems like a lot of German winemakers prefer “longer” cooler fermentations. Can you give me a reference point for what they might consider a long ferment? More in regards to Kabinett-Spatlese (Trocken or not) level wines than the sweeter styles.

Koehler-Ruprecht (among others) has been known to let fermentations go until June or July the summer following harvest (9 months or so.) This probably has a lot to do with the slow wild yeast ferment finishing up when the cellar temps rise in the summer. That is the exception though. The vast majority of producers will have finished within a couple of months.