NOVELTY - Producing ethanol and protein yeast feed, comprises: e.g. inoculating a first quantity of whey permeate with a first quantity of yeast and a first quantity of at least one nutrient source to create an inoculation mixture; incubating the inoculation mixture at 85-95 degrees F; seeding the inoculation mixture by adding a second quantity of whey permeate and a second quantity of a nutrient source to create a seeding mixture; incubating the seeding mixture at 85-95 degrees F; and propagating the seeding mixture by adding a third quantity of whey permeate and a third quantity of a nutrient source.    USE - The method is useful for producing ethanol and protein yeast feed (claimed), where the ethanol is useful as a biofuel, and the yeast protein feed is used for ruminant animals.    ADVANTAGE - The method: utilizes the antibacterial agents, thus inhibiting bacterial growth or contamination; is environmentally friendly; does not require the steps of monitoring and adjusting the pH throughout the process thus cost-effective; consumes less time; and provides greater than or equal to 8.5 vol/vol.% of alcohol after fermentation with up to 95% lactose conversion efficiency.    DETAILED DESCRIPTION - Producing ethanol and protein yeast feed, comprises: inoculating a first quantity of whey permeate with a first quantity of yeast and a first quantity of at least one nutrient source to create an inoculation mixture; incubating the inoculation mixture at 85-95 degrees F; seeding the inoculation mixture by adding a second quantity of whey permeate and a second quantity of a nutrient source to create a seeding mixture; incubating the seeding mixture at 85-95 degrees F; propagating the seeding mixture by adding a third quantity of whey permeate and a third quantity of a nutrient source to form a propagation mixture; combining the propagation mixture with a fourth quantity of whey permeate and a fourth quantity of a nutrient source to form a propagating mixture; fermenting the propagating mixture; and extracting a quantity of ethanol and a quantity of yeast.