To mark the launch of the new “Wine and Pizza” workshop developed by the Bordeaux Wine School, we will take you on a voyage of discovery through a key stage in the creation of these two perfectly matched artisanal products – fermentation.
Yeast is a single-celled fungus and natural living organism capable of triggering the fermentation of animal and plant-based organic matter (and therefore completely different from baking powder, which simply imitates the action of yeast). Whether it’s used for bread or wine, the fermentation reaction is the same. The species responsible for this reaction is Saccharomyces cerevisiae, of which only the strains best adapted to the environment naturally survived before being domesticated by mankind in antiquity.
When subjected to specific temperature conditions, yeast begins to react. The yeast metabolizes the glucose and fructose in the grapes (monosaccharide), as well as the sucrose (when chaptalization is used), into ethanol, CO2, organic yeast matter, and heat.
Which type of yeast to use depends on the different needs of these two entities.
“Bread requires fast fermentation to ensure the glucose is quickly consumed and the carbon dioxide produced as fast as possible. The aim is for the dough to rise before the bread is put in the oven, where the yeast will be destroyed in temperatures above 52°C”, explains Guillaume Comte, Head of Wine/Hygiene France for Soufflet Vigne, a distributor of products for wine and grapevines.
“The carbon dioxide released during fermentation is trapped in the pizza dough by the gluten network, which creates a frame, structured by the presence of protein”, explains Bartolo Calderone, a pizza chef at the Capperi restaurant in Bordeaux, Director of the Ecole Professionnelle de Pizza et Panification Naturelle, and member of the Centre de Recherche Appliquée, Farines, Cultures, Agrobiodiversité de Bordeaux (Bordeaux Center for Applied Research in Flour, Cultures, and Agrobiodiversity).
As it tries to escape, the carbon dioxide stretches the gluten and creates a light, honeycomb structure. The alcohol produced by fermentation evaporates when the pizza is cooked.
For wine, it takes between a few hours to a few days for fermentation to start in a vat. The yeast population needs to multiply enough in relation to the volume of wine for the sugar to be turned into alcohol. Unlike the pizza chef who wants to lock the carbon dioxide in, during winemaking the gas is allowed to escape from the top of the vat (except for sparkling wines).
As the recipe for bread is always fairly similar, a relatively low number of yeast strains are used. For wine, on the other hand, a diverse range of yeasts are available to match the wide range of wines produced, with specific structural and aromatic profiles. Many different factors are considered when choosing a yeast for winemaking, such as the pH, the glucose available, nutrients, and the ability to express the aromas found in the grape varieties and the environment (fermentation).
The winemaker or pizza chef can intervene in the fermentation process in various ways. Sometimes the winemaker will decide to trust the yeast spontaneously present in the must (wild indigenous yeast). This can cause issues with fermentation if the yeast population is insufficient and can lead to the appearance of yeasts that cause changes responsible for olfactory defects in the wine. To prevent fermentation from stopping, winemakers normally use a yeast starter, i.e., “a few kilos of grapes picked before the official harvest and left in the ideal conditions for fermentation to activate the yeasts. The yeast starter is then added to the harvested grapes to naturally inoculate the vat and trigger fermentation”, explains Sophie Blanc, a tutor at the Bordeaux Wine School, Business development and marketing consultant for winegrowers, and winegrower at the Domaine les Carmels (Cadillac Côtes de Bordeaux appellation).
In a similar process, pizza makers can use natural yeast. They can also choose to add active dry yeast (baker’s yeast) to trigger fermentation. In the same way, winemakers can add active dry yeast, which has been isolated and selected from wine must, before being multiplied and produced in industrial quantities. In total, according to Guillaume Comte “30 to 50 strains of commercial yeast exist for wine and are available in different countries under 300 different names.”
As Sophie Blanc tells us, this workshop will correct preconceived ideas that wine created with active dry yeast is standardized or technological. That’s not the case.
In this workshop, the school hopes to once again highlight the accessibility of Bordeaux wines, pairing them with a dish loved by everyone throughout the world.
“Bordeaux wines are not just for special events. Like a good pizza, they should be enjoyed on any occasion, simply and in good company!” Stéphanie Barral, Director of the Bordeaux Wine School, reminds us.
Like their creators, the diversity of Bordeaux wine profiles and pizza styles really play off each other. This wide range means everyone will find a pairing that suits their tastes! To create successful matches, a few general guidelines can be given, such as “pairings based on color, style, region or power”, explains Sophie Blanc.
Examples of matches suggested by the tutor include “Bordeaux rosé wines, whose fresh, light and acidic character pairs well with almost any pizza.” Sweet wines will go well with stronger flavors like a quattro formaggio. “The only limit is your imagination. Be bold!”