The yeast used in bread is generally called:

• Baker’s yeast (common name)
• Saccharomyces cerevisiae (scientific name)

From a Jain point of view:

• Yeast is a living microorganism.
• Using it means intentionally cultivating and killing countless tiny lives, so traditional Jain ethics consider bread made with yeast as non‑acceptable (a‑hitat) for strict followers.
• Many Jains therefore prefer unfermented rotis, chapatis, phulkas, khakhras, or naturally leavened grains without added yeast.