Changes

Many commercial sour beers are bottle conditioned with fresh wine or champagne yeast. If this yeast is still viable, it may contribute to the fermentation profile. For example [[Saccharomyces#Killer_Wine_Yeast|killer wine strains]] can kill ale or lager yeast, and potentially lead to autolysis off-flavors, although reports of autolysis in aged sour beer are next to none, and many believe that autolysis is not a concern in beers containing live ''Brettanomyces'' since ''Brettanomyces'' could potentially consume the compounds that are released during autolysis <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1779575335404006/?comment_id=1782868198408053&reply_comment_id=1783095121718694&comment_tracking=%7B%22tn%22%3A%22R%22%7D DeWayne Schaaf on autolysis flavors. Milk The Funk Facebook group. 08/07/2017.]</ref>. If other flavor contributions by bottling yeast are a concern (esters, thiols, etc.), cooling the beer and leaving the sediment behind may help to alleviate the problem, however , at least some the wine/champagne yeast will probably still be in suspension in the beer. The long term survival of many wine strains of ''Saccharomyces'' yeast is usually limited in a low pH sour beer, so if the beer has aged (~6+ months is an example estimate) then the chances of viable champagne yeast being in the bottle is are low <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1268830686478476/?comment_id=1269605776400967&reply_comment_id=1270016239693254&comment_tracking=%7B%22tn%22%3A%22R%22%7D Conversation with Richard Preiss on MTF. 03/28/2016.]</ref>. Many brewers have had success using bottle dregs that were conditioned with killer strains of champagne or wine yeast, and many consider it not a big concern due to the reasons previously mentioned. See the [[Packaging#Re-yeasting|Packaging and Re-yeasting]] page for more details on killer wine yeast strains. If the brewer wants to guarantee that only ''Brettanomyces'' and/or bacteria are cultured, then they must use isolation techniques to do so <ref>[http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602008000200007 Occurrence of killer yeast strains in industrial and clinical yeast isolates. MARCELO E BAEZA*, MARIO A SANHUEZA and VÍCTOR H CIFUENTES. 2008.]</ref>.