Having too much yeast in a sourdough starter can lead to several consequences, including:
Accelerated fermentation: Yeast is responsible for the fermentation process in sourdough starter, where it consumes sugars and produces carbon dioxide gas and alcohol. If there's an excessive amount of yeast, the fermentation process may happen too quickly, resulting in a faster rise and less development of flavor in the bread.
Overproofing: A higher concentration of yeast can cause the dough to rise too rapidly and overproof. Overproofing leads to a weaker gluten structure, causing the dough to collapse and lose its ability to hold its shape during baking. This can result in a dense and flat loaf of bread.
Altered flavor profile: Sourdough bread derives its distinct flavor from the lactic acid bacteria present in the starter. If the yeast population dominates the bacterial population, the balance of flavors may be disrupted, leading to a milder or less complex taste.
Increased tanginess: While sourdough bread is naturally tangy due to the lactic acid produced by bacteria, an excess of yeast can lead to an increased production of acetic acid. Acetic acid gives a sharper, vinegar-like taste to the bread, potentially overpowering the desired flavor profile.
Unpredictable rise and texture: An imbalance between yeast and bacteria can lead to inconsistent rise and texture in the bread. The excess yeast may cause uneven fermentation, resulting in irregular air pockets and an inconsistent crumb structure.
To maintain a healthy sourdough starter, it's important to maintain the proper balance between yeast and bacteria. If your starter has an excess of yeast, you can try adjusting the feeding routine or altering the fermentation temperature to encourage a more balanced microbial environment.