A sourdough English muffin is a variation of the traditional English muffin that is made using a sourdough starter instead of commercial yeast. The sourdough starter adds a tangy, fermented flavor to the English muffins. It can also make them more nutritious as the fermentation process helps to break down and make more accessible certain nutrients in the dough more. They are typically made by mixing flour, water, salt, milk, eggs, and a sourdough starter, then letting the dough ferment before shaping it into muffin-sized rounds and baking them on a griddle or in a skillet.