A very happy tempranillo indigenous yeast fermentation

Natural wine and biodynamics seems to promote irrational flame wars on the Internet. I have faith in science and personally have trouble buying some of the more voodoo practices myself. On the other hand I can’t argue with the results. Many of the wines I find the most compelling are made using natural winemaking concepts and from vineyards farmed biodynamically. My goal is to become rationally natural.

The intensity of these debates is hard to comprehend after you’ve fermented two hundred tons of fruit without a bag of yeast in sight. My vision of becoming rationally natural is simple: only do what you have to and when you have to do something don’t use bad stuff. Simply minimize or eliminate inputs everywhere.

There is something emotionally rewarding about simply putting grapes into a fermenter and removing the lid a few days later to find fermentation starting without a bit of help from you. It makes you feel more connected to the wine. However, this is not magic, it’s science. When winemakers use cultured yeast strains they knock-off all the indigenous yeast with a dose of sulfur. Then they add their selection of Saccharomyces cerevisiae and it’s off to the races. When our grapes go into a fermenter no sulfur is added so the indigenous yeasts start a less direct process. At the beginning of our fermentations many types of yeasts are present to compete with each other for food. One of the reasons yeast cells produce alcohol is to kill off the competition - not the best system as eventually they kill themselves off. As the fermentation continues the weaker strains of yeasts are killed off until at the end only Saccharomyces cerevisiae, the bad boys of the wine yeast world, are there to take the wine to dryness just like those using cultured yeasts. The difference is that with many types of yeast having been part of the fermentation each adds a nuance, no matter how small, that adds layers of complexity to the wine.

I find wines fermented with indigenous yeasts to have more complex aromatics and a different feel on the palate. Texture in wine is very important to me and I believe much of what consumers refer to as taste is actually the texture of the wine. Building texture is a priority in winemaking for me and I feel fermentation with naturally occurring yeasts enhance the mouthfeel of a wine making it more lively and fresh. Often I find wines fermented with cultured yeast to be more one-dimensional, more focused on basic, straightforward dark fruity flavors. However, certainly this is not always the case as there are hundreds of outstanding wines made with selected yeast cultures.

Obviously what yeast you use for fermentation is only one part of what makes winemaking natural. Personally I’m not big on certifications. I like the idea of taking the best of each and weaving your own relationship to the land and your wine. There is something to be learned from biodynamics, organics, the ideas of Masanobu Fukuoka in the One Straw Revolution and many others. Studying all of these concepts and finding the practices that match your vineyard and region is the best solution for me. The only goal should be what will help me make the best wine possible. Just choosing one discipline does not well represent the complexities of nature.

Being rationally natural is simple: only do what you have to and when you have to do something don’t use bad stuff. That makes sense to me both scientifically, emotionally and rationally.