Neb. Rev. Stat. § 2-3990

Cream for buttermaking shall be pasteurized at a temperature of not less than one hundred sixty-five degrees Fahrenheit and held continuously in a vat at such temperature for not less than thirty minutes, or at a temperature of not less than one hundred eighty-five degrees Fahrenheit for not less than fifteen seconds, or any other temperature and holding time approved by the director that will assure pasteurization and comparable keeping-quality characteristics.