Beer styles that can be brewed using this method include [[Berliner Weissbier]] and the subcategories of [[American Wild Ale]], which include [[Mixed-Fermentation Sour Beer]] and [[Soured Fruit Beer]] <ref>[http://www.bjcp.org/docs/2014%20BJCP%20Style%20Guidelines%20%28DRAFT%29.pdf BJCP 2014 Style Guidelines Draft.]</ref>. European sour styles such as [[Lambic]], [[Gueuze]], and [[Fruit Lambic]], technically can only be produced by [[Spontaneous Fermentation]]. [[Flanders Red Ale]] and [[Oud Bruin]] styles can be brewed using pure cultures, but can also be brewed using spontaneous fermentation or a mix of using pure cultures and spontaneous fermentation.
===Souring a Non-Sour Beer===
(This was in the Intro to traditional method, Cut or move to own section?)
This method is best described by the following: Brewer X has a beer, and perhaps that beer didn't come out the way they wanted, or perhaps there is some other motivation, but Brewer X decides that they want this beer to be sour. Great idea, right? Perhaps. [[Lactobacillus]] tends to prefer simple sugars, which are required for lactic acid production. [[Pediococcus]] can break down some of the larger chain sugars that are left over in the beer from the [[Saccharomyces]] fermentation, but there may not be enough of those sugars to create even a moderate level of acidity. If the beer contains more than 6 IBU's, the bacteria may be largely inhibited. The [[Brettanomyces]] in general should create a nice range of flavors (see [[Funky Mixed Fermentations]]) in secondary, so this could benefit the beer. However, due to the lack of sugars, finished beers which a brewer may attempt to sour often do not get very sour at all. Some brewers have reported good results with this technique (particularly professional brewers who use barrels; see "American Sour Beers" by Michael Tonsmeire for more information), but in general if the brewer is going for a truly sour beer, it is better to use another method.
If this method is used, it generally requires 6-12+ months, which is required for the Brett and Pedio to break down the remaining complex sugars.
==Traditional Method - Long Fermentation==