The most important work in our cellar at the moment is monitoring and controlling fermentation. Of course, by control, I mean by the use of temperature. The fermentation can take place at more or less the required speed (within certain boundaries), decided not only by the wine maker and their preferred technique, but also by the type of yeast used to seed the tanks. (Some yeasts are far more vigorous than others and work within entirely different temperature ranges).
Generally speaking, fermentation carried out quickly, and at higher temperature, will produce a very fruity, easy drinking style, that will be ready consume shortly after the wine making process is complete. By using lower temperatures over a longer period, the wine might not have the same instant appeal and will usually require more time before it is consumed – but that’s really the point. It is up to the winemaker to decide their personal preference, and of course, will also be influenced by the target market and how long the wine might be required to last. The warmer, faster fermentation will normally sacrifice shelf-life, whilst the longer, cooler fermentation will slow down and extend the evolution of the finished wine, thereby ensuring better ageing potential. If extended lees contact is added to the wine making process, following on from the end of the fermentation, then this can change the physiology of the wine completely – extending ‘shelf life’ even further, whilst also adding more character and complexity.
During the fermentation we sometimes see strange patterns of foam forming on the surface of the tanks. Clearly this has something to do with the yeast, and the way that it behaves, but to be honest I have researched this and cannot find any specific explanation. I will keep looking.
In the meantime my photo shows one of our tanks (on the right) and the planet Saturn (on the left). I just thought that they looked quite similar!