Hydration Percentage in baking is a calculation that represents the ratio of water to flour in a recipe by weight. In sourdough, it is the primary variable controlling crumb openness.

Inoculation Rate is the percentage of starter added to a dough relative to the total flour weight. For example, adding 200g of starter to 1000g of flour is a 20% inoculation. This variable acts as the "accelerator pedal" for fermentation.