Changes

Champagne/wine yeast could produce flavor compounds such as esters and thiols if it is introduced into wort during primary fermentation. When dregs containing viable Champagne/wine yeast are added to a starter, then that yeast will often grow into a healthier population, which could then have a large flavor impact from the Champagne/wine yeast if the starter is pitched into primary. If flavor contributions from bottling yeast are a concern (esters, thiols, etc.), then cooling the beer and leaving the sediment behind before building a starter may help to alleviate the problem, however, at least some the wine/champagne Champagne yeast will probably still be in suspension in the beer. Dregs or a starter from dregs containing champagneChampagne/wine yeast could be added after primary fermentation, which would eliminate any potential for the Champagne/wine yeast having a significant impact on the flavor as far as producing esters from fermentation. Additionally, the long term survival of many wine strains of ''Saccharomyces'' yeast is usually limited in a low pH sour beer, so if the bottled beer has aged for 6+ months then the chances of viable champagne Champagne yeast being in the bottle 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 Champagne or wine yeast, and many consider it to be not a big concern due to the reasons previously mentioned. 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>, or verify with the producer of the beer being used to see if Champagne or wine yeast was used for conditioning.