How do jail inamtes get yeast to make alcohol?

Inmates may obtain yeast for making alcohol through various means, such as smuggling it in from outside or using ingredients available in the jail, like bread. Some might also cultivate yeast from fruits or other food items. Additionally, they can repurpose food items that contain yeast, like certain baked goods, to ferment and produce alcohol. However, such activities are generally against prison regulations and can lead to disciplinary actions.