Ahh, it may have been the heat pasteurization that did it in. If you care to glance at a scientific paper, here’s an interesting source. pubs.rsc.org/en/content/…/c9ra01533g I want to say I’ve seen a low temp method of pasteurizing (that you have to hold for a good bit longer) but for mine I avoided heat like the plague and did everything cold with a huge starter to ensure the yeast outcompete anything and fill the fermenter with alcohol to handle any potential unwanted microbes