Changes

A regular strength starter (1.030-1.040 SG) of a volume of 2-3 cups should be prepared for the bottle dregs. Hops should not be used unless the brewer wants to try and suppress the ''Lactobacillus'' in the commercial beer (''Lacto'' strains for some commercial breweries are fairly hop tolerant up to 20-25 IBU. See [[Lactobacillus#Hop_Tolerance|Lactobacillus Hop Tolerance]] for more information). If the brewer has only one bottle or wants to keep multiple bottle dregs separate from each other, the starter wort can be poured directly into each bottle and covered with aluminum foil or plastic wrap. Alternatively, the dregs from multiple bottles can be combined into a single vessel (such as a an Erlenmeyer flask or glass jug) with the starter wort, and covered sealed with aluminum foilan airlock (creating an anaerobic starter with an airlock is preferred unless the brewer knows that aeration won't create excessive amounts of acetic acid; it's best not to take a risk with aeration the first time you use dregs from a particular commercial brewery <ref name="BryanHeit_starters"></ref>).  Although more experiments and probably needed, plastic wrapagitation is believed to be an important factor for any species of microbe (yeast and bacteria). Gentle stirring on a stir plate or orbital shaker, or an airlockfrequent gentle manual agitation leads to faster growth and a higher number of organisms. Agitation keeps the microbes in solution. It also maximizes the microbes' access to nutrients and disperses waste evenly. In a non-agitated starter, the microbes are limited to the diffusion rate of nutrients, leading to a slower and more stressful growth <ref name="BryanHeit_starters">[https://www.facebook.com/groups/MilkTheFunk/permalink/1168024059892473/?comment_id=1174865305875015&reply_comment_id=1176092372418975&total_comments=1&comment_tracking=%7B%22tn%22%3A%22R9%22%7D Conversation with Bryan Heit about starters and agitation. 11/09/2015.]</ref>. For more information regarding aeration and agitation effects on ''Brettanomyces'' growth, see [[Brettanomyces_Propagation_Experiment|Mark Trent's Brettanomyces Propagation Experiment]]. The starter should be stored at room temperature, or can be stored at a higher temperature if bacteria is the main microbe that the brewer is after. The mouth of the bottle may be flamed with a lighter to kill any wild yeasts that might have landed on the area. Keep the starter for at least one week, and monitor for activity. Visual activity may not always be present, may be brief, or minimal. Monitoring the pH and the gravity can assist the brewer with deciding whether or not the commercial sour beer has any viable microorganisms still alive in it.