leavening agent; yeast (for bread)
Specifically refers to a leavening agent used in bread making, such as yeast or sourdough starter.
To ferment the bread leavening agent, you need to place it in a warm spot.
Using a natural yeast leavening agent gives a unique flavor.
Compound of パン (bread) and 種 (seed, source, material). The term likely arose from the idea of a 'seed' or starter culture used to leaven bread.