Changes

'''Wort Souring''' is the process of "[[Mixed Fermentation]]" (in the case of lactic acid bacteria being left alive to co-exist with yeast) or "Sequential Fermentation" (in the case of kettle sours) where lactic acid bacteria are given a "head start" as it's pitched pre-ferment and acidify wort before the yeast so that it will be able is pitched to produce significant amounts of lactic acid before the ''Saccharomyces'' completes complete the main alcoholic fermentation. While non-sour beer falls in the range of 3.8-4.6 pH, a final pH between 3.0 and 3.7 is the general target range for the soured wort and also the finished sour beer (although [[Titratable Acidity]] is more accurate for measuring perceived sourness). This is a broadly defined technique and there are many variations on souring wort. These include mixed fermentation methods such as souring in the primary fermenterfor a short time period before adding yeast or co-fermentation with yeast, souring in a secondary vesselafter primary fermentation with yeast, or sequential fermentation such as souring in the boil kettle itself ('''kettle souring''')where the lactic acid bacteria is killed before yeast is added. There are also various methods of inoculating the wort with ''Lactobacillus''. Finally, the brewer has the option of pasteurizing the wort by heating it to kill the ''Lactobacillus'' before adding the yeast for the main fermentation.