Freezing and Fermentation Performance
Frozen doughs can be stored for long periods at temperatures below 0°C. Low temperatures generally decrease dough leavening due to an overall loss of yeast viability, which ultimately leads to a significant decrease in final bread quality. Indeed, temperatures below 0°C leads to water expansion and crystals formation inside yeast cells which can rupture cell walls, thus reducing fermentative performance.
Yeast’s cryoresistance, also referred to as yeast’s ability to maintain its gassing activity when frozen, depends on its trehalose content. Trehalose, a carbohydrate produced and present in yeast’s cells serves as an energy reserve and protects against stress.
When producing yeast, a trade-off between levels of trehalose and protein must be done. Increasing yeast’s trehalose content will improve its cryoresistance, but reduce its protein content whereas increasing yeast’s protein content will provide yeast with a better gassing power but less trehalose.
Yeast that is high in trehalose:
- Is more stable
- Has a longer shelf life
- Stays dormant longer
- Gets activated more slowly
Yeast freshness and handling are important for frozen doughs as yeast consumes trehalose and loses cryoresistance when exposed to high temperature or to oxygen. Proper dough handling (e.g. keeping dough cold, short time between mixing and freezing) helps to conserve trehalose and thus optimizes cryoresistance.
Frozen doughs can be stored for long periods at temperatures below 0°C. It is not only important to remain the quality consistent during the entire shelf life of the dough but also during the process from freezer to oven.
By optimizing the application recipe and process conditions the quality of the dough can be remained as optimal as possible. Special attention needs to be paid to the flour quality, type of yeast, reducing agents, enzymes and hydrocolloids used. Next to that the process-, freeze- and baking conditions play a major role as well.
A balanced recipe and process conditions improves the volume, appearance, organoleptic qualities and cryoresistance. Not only for the frozen dough but also in the final baked good.
At Lallemand Baking Solutions we develop exclusively, in close co-operation with our customers, the best performing enzymatic and sensory solutions based on their own recipe.