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'''Funky mixed fermentationsBrettanomyces and Saccharomyces Co-fermentation''', for the purposes of this article, refer is a type of [[Mixed Fermentation|mixed fermentation]] that specifically refers to fermentations that contain ''[[Saccharomyces]]'' and ''[[Brettanomyces]]''. They do not contain significant amounts of [[Lactic_Acid|lactic acid]] produced by lactic acid bacteria such as (''[[Lactobacillus]]'' and ''[[Pediococcus]]''). As such, these beers may have a lightly tart flavorfrom [[Acetic_Acid|acetic acid]] production by ''[[Brettanomyces]]'', but are generally not described as being sour if properly brewed (see the [[Mixed Fermentation]] pagefor mixed fermentation sour beers). The flavor of beers fermented with ''Saccharomyces'' (generally ale yeast, but they can also be fermented with lager yeast) and ''Brettanomyces'' is often dominated by the array of flavor compounds produced by ''[[Brettanomyces]]'', unless the beer is young in which case the ester and phenol profile of the fermenting strain of ''Saccharomyces'' might still have an impact on the flavor. In the case of young beers, the flavor profile will begin to be changed by ''Brettanomyces'' as esters, phenols, and fatty acids are created and metabolized.

Generically speaking, these flavors almost always consist of both fruity esters and phenolic components. Sometimes they also consist of an array of other flavors that are generically described as "funky". Specifically, fruity esters range from tropical fruits to stone fruits to citrus fruits, and are produced by all strains of ''Brettanomyces'' to some degree. Phenols, fatty acids, alcohols, aldehydes, and other compounds can also create a wide range of flavors including smoke, "barnyard animal", bitterness that lingers on the palate longer than hop bitterness, horse blanket, sweat, body odor, rancid cheese, etc. For more information on the identification of these compounds and the known conditions that impact their production, see [[Brettanomyces#Brettanomyces_Metabolism|''Brettanomyces'' metabolism]]. For 100% ''Brettanomyces'' beers, see [[100%25_Brettanomyces_Fermentation|100% ''Brettanomyces'' Fermentation]].

<!-- Removing graph for now due to out of date information[[File:Funky_Ferm.jpg|thumb|upright=2.5|Conceptual graph of traditional microbe and wort dynamics|Conceptual graph of dynamics of funk expression and inoculation timing of Brettanomyces. Y-axis for each microbe group depicts relative activity which combines in a conceptual sense: growth, attenuation , and production of flavor compounds. Plot was drawn by Drew Wham based on concepts discussed in American Sour Beer <ref> Tonsmeire, M. (2014). American Sour Beers. Brewers Publications </ref> . See the table to the left for updated information on where this graph may no longer be accurate. ]]-->

| Inoculation timing || After ''Saccharomyces '' has finished fermentation || At the start of Fermentation || See figure 1The timing of the ''Brettanomyces'' pitch may not have a significant effect a lot of the time; pending data from George Van Der Merwe or another source of scientific data <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2103639509664252/?comment_id=2117621214932748&comment_tracking=%7B%22tn%22%3A%22R%22%7D Richard Preiss. Milk The Funk Facebook thread on co-pitching versus subsequent pitching of ''Brettanomyces''. 06/04/2018.]</ref>.

| Strain of ''Saccharomyces'' || Phenol positive strain || Phenol negative strain || POF+ strains of ''S. cerevisiae'' form 4-vinylguaiacol by enzymatic decarboxylation of ferulic acid <ref> Coghe, S., Benoot, K., Delvaux, F., Vanderhaegen, B., & Delvaux, F. R. (2004). Ferulic acid release and 4-vinylguaiacol formation during brewing and fermentation: indications for feruloyl esterase activity in Saccharomyces cerevisiae. Journal of Agricultural and Food Chemistry, 52(3), 602-608.</ref>. More recent data suggests that POF+ strains of ''Saccharomyces'' are not necessary for ''Brettanomyces'' to create phenols because ''Brettanomyces'' can create the precursor 4-vinyl phenols on its own as long as ferulic acid and other grain derived percursors precursors are available <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1585065488188326/?comment_id=1585068344854707&reply_comment_id=1585072311520977&comment_tracking=%7B%22tn%22%3A%22R3%22%7D Conversation with Richard Preiss on MTF. 02/16/2017.]</ref>. See [[Brettanomyces secondary fermentation experiment]] and [https://www.themadfermentationist.com/2014/09/phenols-and-brett-fruity-and-funky.html?m=1 this The Mad Fermentationist blog article].

| Ferulic Acid (malt derived) || More Ferulic Acid || Less Ferulic Acid || A precursor of 4-vinylguaiacol. Perform a [http://braukaiser.com/blog/blog/2010/06/04/how-much-effect-does-a-ferulic-acid-rest-have/ ferulic acid rest], and use grains that contain more around 70% barley malt and 30% wheat malt for the highest ferulic acid such as wheatextraction (see [[Brettanomyces#Phenol_Production|''Brettanomyces'' phenol production]] for more information).

==Finishing Funky Mixed Fermentations==Aging and Packaging===Bottling In general, beers brewed with ''Saccharomyces'' and Kegging===''Brettanomyces'' tend to lead to a slow fermentation by the ''Brettanomyces'', which can hyper-attenuate the beer over time (see [[Brettanomyces#Carbohydrate_Metabolism_and_Fermentation_Temperature|''Brettanomyces'' carbohydrate metabolism]]. These beers are often aged for at least 3-4 months to wait for a stable final gravity before packaging. However, they can also be aged for longer which helps develop flavors produced by the ''Brettanomyces''. Due to the potential for acetic acid development when exposed to oxygen over time, care should be taken when aging any beer with living ''Brettanomyces'' (see [[Mixed_Fermentation#Aging|mixed fermentation aging]]). See the [[Packaging]] pagefor instructions on determining when it is safe to package a ''Brettanomyces'' and ''Saccharomyces'' Co-fermentation, and tips on how to package it.

One method that some brewers attempt is adding a small pitch of ''Brettanomyces'' to a clean beer at bottling time. This can be done either in the bottling bucket/tank, or added to each bottle individually. If adding ''Brettanomyces'' to each bottle individually, a 1 mL dosage of ''Brettanomyces'' from a starter should be enough since pitching rate seems to have little impact on the beer <ref>[[Brettanomyces_secondary_fermentation_experiment]]</ref>. Some brewers believe that adding the ''Brettanomyces'' at bottling time results in a more complex beer. It is speculated that the extra stress of pressure within the bottles helps to create this complexity, although evidence for this is lacking. Other stressors such as lack of oxygen are also speculated to have an impact.

One challenge with this approach is that it is difficult to predict how much ''Brettanomyces'' will further attenuate the beer once in the bottle. Over-carbonation and bottle bombs can easily be an issue with this method if the brewer is not careful. Each degree Plato adds ~2 volumes of CO2 <ref>[http://braukaiser.com/wiki/index.php/Accurately_Calculating_Sugar_Additions_for_Carbonation#Remaining_or_Residual_Extract "Accurately Calculating Sugar Additions for Carbonation." Kai Troester. Braukaiser.com. Retrieved 08/07/2016.]</ref>. Since different species and strains of ''Brettanomyces'' ferment different types of sugars, some strains might be safer for dosing at bottling time. For example, most strains of ''B. anomulus'' do not ferment maltose, which is around 50% of sugar in wort, so this makes it a good choice for adding to the beer at bottling. However, if the amount of additional attenuation is already known for a particular beer and a particular strain of ''Brettanomyces'', than any strain can be used.  Daniel Addey-Jibb, co-owner and brewer at Le Castor near Montreal, Quebec advises that the approach that his brewery takes is to ferment their saison wort down to 1°P. Once at 1°P , the beer is cold crashed, fined, and then bottled with ''Brettanomyces''. The beer is then stored at room temperature for three months to condition naturally in the bottle. During bottling conditioning, their ''Brettanomyces'' culture takes the beer down below 0°P, and their desired level of carbonation is reached. This process took Addey-Jibb's team dozens of trials to perfect using their specific wort recipe, saison yeast, and ''Brettanomyces'' strain. Different species or strains of ''Brettanomyces'' might ferment differently, and different wort compositions might also ferment differently. For example, Addey-Jibb's saison is mashed with malted barley, wheat, and rye at a low temperature so there are not many higher chain sugars, allowing the beer to dry out quickly <ref>[http://www.thebrewingnetwork.com/session-le-castor/ Addey-Jibb, Daniel. Interview on the Brewing Network's Session podcast. 10/04/2016.]</ref>. Other wort compositions that include higher chain sugars from specialty malts and/or higher mashing temperatures might ferment much slower, and thus knowing what the final gravity will be once ''Brettanomyces'' is added is difficult to know without running trials on that specific fermentation profile. It is recommended to use Belgian beer bottles of sparkling wine bottles that can withstand higher pressures than regular beer bottles just in case over-carbonation becomes an issue.