Methane is one of the most potent greenhouse gases that contributes to the global climate crisis. As this gas is produced in the digestive systems of cattle, methane represents one of the greatest problems faced by the farming industry. Dr Robert Bryant, Dr Langdon Martin and their team at Warren Wilson College, North Carolina, propose an innovative feed supplement for cattle that helps to significantly reduce methane emissions: waste yeast from craft breweries. If used on a large scale, this new supplement could significantly decrease emissions associated with cattle farming, while also creating a new use for a waste product of the craft beer industry.