These are
yeasts used in the brewing Process and which have certain properties, including:
- The ability to convert certain sugars to alcohol
- Reduce diacetyl thereby avoiding 'buttersoctch ' flavours in the beer
These fall into 2 main categories-
- Saccharomyces Carlsbergensis
- Saccharmoyces Cerevisiae
To ensure purity of strain , a 'clean' sample of the
Yeast is stored in a laboratory environment at refridgerated temperature. After a certain number of fermentation cycles , a full scale
propagation is produced from this laboratory sample. Typically, it is grown up in about 3-4 stages using sterile Brewing
wort and oxygen / air.