From Salted: a Manifesto on the World's Most Essential Mineral by Mark Bitterman. Copyright © 2010 Mark Bitterman. Published by Ten Speed Press, a division of Random House, Inc. All Rights Reserved.
If you have tried a Belgian lambic beer, then you have tasted the results of spontaneous fermentation. The beer is exposed to naturally occurring yeast and bacteria in the open air, and matured in oak barrels for months or years. Greg Engert, beer director for the Neighborhood Restaurant Group in Washington, D.C., explains.