You've probably seen a number of “lawn tonics” circulating on the Internet claiming that common household products like beer or cola will effectively fertilize your lawn. Not true. The simple sugars in these drinks are, won't keep your lawn healthy; just like people they need complex carbohydrates to grow. Likewise the yeast in beer will not encourage healthy microbes to grow, but rather fungus. Don’t waste your time, or your beer, on this one.