A Sticky Situation
Jessica wrote this a few weeks ago, but in all honesty, harvest just finished for a lot of producers, winemakers and vineyard managers. This was an incredibly long harvest. It began early with an early bud set and the very mild, lovely, long fall we had led to harvesting into November. Without further ado - Jessica.
It finally over! The grapes are all in, the weather has turned cold and we are busy “putting the wines to bed”, i.e. putting the new wines into barrel for storage. This harvest felt particularly long because we got started so early, but also because it was a bit of a nail biter with some of our fermentations. We saw very slow, sluggish ferments in both our Malbec and Cabernet Sauvignon this year. After talking with other winemaking friends, it turns out we were not alone.
Warning, we are about to get a little nerdy: So, what was the problem? It seems like there may have been a lot of yeast coming in on the grapes from the vineyard, which created competition during fermentation. Competition between yeast strains during fermentation can lead to slow or stuck fermentations. Towards the end of each of our fermentations, we looked at the amount of glucose and fructose (sugars) that were left in the grapes. In each of our sluggish ferments, there was a lot more fructose than glucose. Why does this matter? Most yeast strains need one glucose present for every fructose to be able to successfully consume the fructose. If there is a bunch of fructose present, but not very much glucose, the yeast cannot continue to “eat” the sugar. Luckily, there are a few yeast strains that are fructophilic, that is, they like to eat fructose. So, we re-inoculated our ferments with a fructose-loving yeast and the fermentation was a success. Why didn’t we just use a fructose-loving yeast to begin with? These fructophilic yeasts are absolute beasts! They chew through sugar and blast through fermentation – not ideal for creating nuanced wines. We start our ferments with a yeast strain that we feel will enhance the varietal and hope that it can get the job done. When things look sticky, we bring in the big guys and cross our fingers that it will work. The key is to catch the problem and reinoculate your fermentation early enough, so the new yeast can acclimate and get the job done.
The silver lining to all the worrying, analyzing, and nail biting is that these long, slow fermentations resulted in absolutely beautiful wines. Because the fermentations never really “took off”, that is, they never got very warm and progressed very slowly, the aromatics are amazing, and the flavors are intense.
The moral of the story: a sticky situation can be a good thing. Beauty from chaos.