Changes

The most basic method for making a mixed fermentation sour beer is to brew some simple wort (fresh extract or all grain) that is low in IBU's. Iso-alpha acids can inhibit many species and strains of LAB. Keeping the wort less than 6 IBU's is recommended in general, unless the brewer has information about their LAB culture that indicates that they can tolerate more. Mash hopping is one technique that can be used to limit the IBU's by about 70% <ref>[http://www.homebrewersassociation.org/attachments/presentations/pdf/2014/Putting%20Some%20Numbers%20on%20First%20Wort%20and%20Mash%20Hop%20additions.pdf Putting Some Numbers on First Wort and Mash Hop additions. David Curtis. NHC 2014.]</ref>. If hops are not required (commercial brewers may be required to use hops, while homebrewers aren't), they can be completely excluded from the recipe. The wort is often mashed at a high temperature to encourage the inclusion of complex carbohydrates in the final wort. The wort is then Primary fermented with a Saccharomyces strain to achieve the majority of attenuation, leaving behind the complex carbohydrates. The primary fermentation is then inoculated with a mixed culture of Brettanomyces, Lactobacillus and Pediococcus, either by moving the wort into barrels with active cultures or by inoculating the primary fermentation vessel (i.e. glass carboy when the method is used by home brewers). This inoculation then starts a secondary fermentation of the remaining complex carbohydrates which follows a slow progression between the microbes that are primarily active. This secondary fermentation may not show readily apparent sighs of active fermentation as in the primary fermentation but is often accompanied by the slow evolution of CO2 in the first 8 weeks and the eventual formation of a pellicle which may form quickly or very slowly.    This method has been used by some brewers before a lot was known about sour brewing microbes and before some of the more current techniques were popularized (such as [[Sour Worting]], or the other methods mentioned in this article).