In a post he published recently, “Angels and Demons, cultured yeasts vs. ambient,” Slowfood editor Fabio Giavedoni points to five basic approaches to fermentation — spontaneous and inoculated. I’ve translated them below.
He and Jancis Robinson Italian editor Walter Speller will be leading a seminar on the “culture vs. ambient” debate at the TerroirMarche festival to be held in Ascoli Piceno on May 16-17.
“Whatever Happens Happens” Spontaneous Fermentation
The grapes are picked, transferred to a vat, and nothing is added. No yeast, no sulfur, no additives or even naturally occurring substances. The temperature is left unchecked. Bottom line: You do nothing but you hold a lucky charm in your hand (if you’re superstitious) or you pray to some saint (if you’re religious) and you just wait and see.
“Old School” Spontaneous Fermentation
The grapes are picked and are transferred to a vat after a careful selection of the bunches. Sulfur is added to avoid the development of harmful bacteria. You check on the fermentation many times every day to see how it’s going.
Controlled Spontaneous Fermentation
A few days before the harvest, you make a nice pied de cuve with some healthy grapes and you take care to make sure that it “stays alive” by checking it and tasting it continuously. Then you harvest and transfer the grapes to a vat. You add the pied de cuve, you regulate the temperature, and you carefully monitor what happens every day to see how it’s going.
Inoculated Fermentation Using Cultured Ambient Yeasts
You pick the grapes and transfer them to a vat. You had yeasts that have been identified in the vineyards and reproduced in a laboratory (they are used to eliminate the risks of spontaneous fermentation and to maintain the uniqueness of the ambient yeasts found in those vineyards). You check the temperature (some do this more or less than others) and you can add sulfur if you like. In the end, you monitor the fermentation daily to see how it’s going to turn out.
Inoculated Fermentation Using Commercial Cultured Yeasts
You pick the grapes and transfer them to a vat. You then add the yeast from the little packets that you can buy at the store (there are all kinds of these). And you add a lot just to make sure — but not totally sure — that they will ferment the must. You check the temperature and generally, you add sulfur. You don’t need to spend too much time monitoring because you know how it will turn out.
Image via Rising Damp.