Bread dough sealed in a can may go off with a bang, warns Gist-Brocades
NV of Delft in the Netherlands. The firm says it is only safe to seal dough
in a can if chemical leavening is used. Common baker’s yeast produces so
much gas, even at low storage temperatures, that the can may explode. Gamma
irradiation stops the process, but kills the cells. European application
556 905 tells how to can dough with natural, living yeast that is unusually
susceptible to cold.
Yeast is blitzed with ultraviolet radiation to cause random gene mutations.
The mutant yeast is then incubated, and tested for any strain that stops
working when cold. The selected strains are then bred, and used for canning.
The ideal mutant strain works happily in dough at room temperature,
but as soon as the temperature drops to below 10 °C it goes into temporary
hibernation and stops producing carbon dioxide from sugar. So as long as
the dough is kept cold, there is no risk of the can bursting. When the temperature
rises, the yeast revives and starts fermenting again.