30 Sep How to create taste in breadmaking? The specific role of sourdough
Sourdough: yeasts + bacteria
Sourdough was the very first ferment to be used in the manufacture of bread. It is obtained from a mixture of flour and water typified by the metabolic activity of a mixed population of lactic bacteria and yeasts.
Every type of yeast or bacteria lends specific aromatic notes to bakery goods, depending on their respective metabolism and breadmaking conditions (ingredients and process), hence the large number of molecules, including superior alcohols, carbonyl compounds, esters and organic acids, constituting the bread’s aroma (Galey et al., 1994; Hansen and Schieberle, 2005; Petel et al., 2017).
The organoleptic properties of sourdough
Sourdough-based fermentation, for example, generates lactic and acetic acids, which contribute greatly to the flavour of the final product, and levels of which depend on the fermentation conditions (Callejo et al., 2011; Petel et al., 2017).
The acidity of the sourdough varies according to temperature and hydration:
- a liquid sourdough produced in warm conditions will generate more lactic acid, hence a mild, sour-tasting loaf.
- a solid sourdough produced at colder temperatures will promote the synthesis of acetic acid, and therefore give a bitter, more-aggressive-tasting loaf (iNbP, 2003).
One solution to the process: facilitator ingredients
The organisational constraints linked to the implementation of flora in spontaneous sourdoughs have greatly inhibited this traditional practice. Today, bakers have the benefit of sourdough starters, or ready-to-use sourdoughs. These latter offer both the quality of the spontaneous sourdough and the stability they formerly lacked. Combined with the use of specific flours, they can contribute interesting properties, such as the production of special aromatic compounds (Hansen and Schieberle, 2005).
NB: There are also dehydrated sourdoughs, bereft of any fermentative activity, but which are sources of rich, complex aromas, directly obtained from the sourdough from whence they come. They are capable of enhancing or correcting a pre-existing aromatic profile in the dough (iNbP, 2003).