Recycling Used Beer Yeast for Environmental Protection

Brewer’s yeast used to make beer is typically discarded once it’s no longer needed. Sometimes, though, the leftover yeast is mixed into livestock feed as a source of protein and vitamins. Now, there may be even more reason to continue this practice, according to findings by a team of scientists with the Agricultural Research Service. Laboratory results suggest that using leftover brewer’s yeast as a feed additive may benefit the environment by helping cows belch less methane into the air as a greenhouse gas that contributes to global climate change. Although spent brewer’s yeast is sometimes used as a livestock feed additive, further cow feeding trials are necessary to fully assess its potential to reduce methane and ammonia on a farm scale, according to the researchers. Those results should give a better idea of the yeast’s potential role as part of a larger, integrated approach to making animal agriculture more environmentally sustainable.