Now, 24 hours after harvesting, we were finally left with a clean Sauvignon blanc juice which had started with the process of fermentation. No hiccups so far! The aim of the yeast we had added is to “eat” the sugar and produce CO2, heat and, most importantly, ALCOHOL. The process normally starts very slowly, but as the yeast cells multiply in numbers, the fermentation process gains tempo. The yeast produces heat, and the heat speeds up the fermentation.
When making Sauvignon blanc, our goal is to have a slow fermentation. The slow fermentation allows the yeast more time to produce very valuable flavour compounds. The only way to control the fermentation speed is to manage the temperature. This, of course, is where our very “powerful” cooling system had to perform! I was not in the least worried: we had designed our state-of-the-art cooling system ourselves, so naturally it was going to work…And it did, in the very early stages of fermentation at least! We pumped the ice water from the container and sprayed it around the outside of the fermentation tanks. Now, I have to tell you, that you don’t play around with these things. As professional winemakers, we most definitely had a plan B in worst case scenario. My faith in the system slowly departed as the wine gained in temperature. The cards were on the table: I was defeated! Our cooling system didn’t make the cut. We then moved the tanks into a cool room on the neighboring farm, turned the temperature down to below 10 degrees and kept the wine stable at 13 degrees for the rest of the fermentation process.
As the yeast turns the sugar into CO2, heat and alcohol, the sugar levels naturally drop. You are therefore able to stop the process as soon as your desired sugar levels are reached. Our aim was to produce a dry wine, and we allowed the process to carry on right to the end until no sugar was left.
Now, the wine only had to be stabilized and blended before we could bottle it. The worst was definitely over: THE WINE HAD MADE IT! But I think the nerves of my close family members may not have. Suffice to say, I now only share with them on a need to know basis.
Next month will be the last chapter in this series. Until then.