Changes

The spontaneous fermentation of lambic is a complex process involving a succession of bacteria and yeasts that progresses along with the chemical changes that occur during fermentation.<ref name=GeuzeKriek>Jef Van den Steen, [[Books#Geuze & Kriek: The Secret of Lambic Beer|Geuze & Kriek: The Secret of Lambic Beer]], 2012</ref> The spontaneous fermentation process has shown considerable variability even among different barrels of beer from the same brewery,<ref name=Spitaels> F. Spitaels, A. D. Wieme, M. Janssens, M. Aerts, H.-M. Daniel, A. Van Landschoot, L. De Vuyst, P. Vandamme [http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0095384 | The Microbial Diversity of Traditional Spontaneously Fermented Lambic Beer], 2000</ref> though all spontaneously fermented beers appear to follow a general sequence of microbes, which can be broken into four distinct stages:<ref name=AWAs>Nicholas A. Bokulich, Charles W. Bamforth, David A. Mills. [http://journals.plos.org/plosone/article?id=10.1371/journal.pone.00355077 0035507 | Brewhouse-Resident Microbiota Are Responsible for Multi-Stage Fermentation of American Coolship Ale], PLoS One, 7(4), 2012</ref><ref name=Oevelen77>D. Van Oevelen, M. Spaepen, P. Timmermans and H. Verachtert, [http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1977.tb03825.x/abstract |MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION IN THE PRODUCTION OF LAMBIC AND GUEUZE], 1977</ref><ref name=Spitaels />