Changes

Most ''Lactobacillus'' species have a thermal death rate of ~145°F (63°C). Freezing without glycerol will kill most cells, but it is possible for a very small number of cold-resistant mutant cells to survive <ref>[http://fermentationnation.net/2015/11/episode-26-quality-assurance-w-jessica-davis-of-the-bruery/ Fermentation nation Podcast interview with Jessica Davis, QA for The Bruery.]</ref> (~1:19:00 in). Some strains have been identified as being extremely thermotolerant, for example [https://patents.google.com/patent/US20180042256A1/en this patent] claims that a strain of ''Lactobacillus delbrueckii'' subsp. ''lactis'' can acidify milk within 2.5 hours when held at temperatures between 45-65°C (113-149°F).