White wine the death knell of northern viticulture. The vine disappeared from northern Germany and Baden, and the maximum altitude for viticulture descended to 220 metres. Hans-Jürgen Otto noted that: "all the vineyards suffered and decreased in area". In England the vine also disappeared. The less early vineyards preferred to select white varieties of grapes because, even if unripe, white grapes allowed wine that was a little sour to still be consumable, while red grapes do not give enough colour and green tannins make the wine bitter. The interruption of the fermentation by a cold winter led to the discovery of the
Colour recovery Combining the video-recorded colour signals with the monochrome telerecordings is a non-trivial task, requiring digital processing (for example matching up the different screen sizes of the two recordings). Thus, it wasn't until the early 1990s that cheaply available, sufficiently powerful computer hardware and software made this task particularly practical at that time. Black & white TV systems predate colour, and so subsequent analogue colour broadcast systems have been designed with backwards-compatibility in mind (known as a "compatible colour" system). Thus, the chrominance (colour) signal is typically 'shoe-horned' into the same channel as the luminance (brightness) signal, modulated on a fixed