Here is what I posted in the "Single malt recipe advice" thread
I have been brewing beer for 35 years plus and have never had an infection, when I started into distilling and did not boil the wort before fermenting I have had quite a few infections, they always seem to occur after the fermentation is complete, I have a theory that a lot of these infections are aerobic and need oxygen to develop, when the wort is fermenting vigorously there is a blanket of CO2 on top expelling the oxygen, as soon as the CO2 production stops at the end of the fermentation oxygen can easily percolate in to the fermentor and hey presto, the aerobic infection gets going, it was there all the time most likely from lactobacillus on the grain, it just needed the oxygen to make it happy (and you unhappy). This is a great site on sour beer that explains a lot of this with some great pictures of infections.
http://hookedonhops.com/2014/09/14/sour-beer-culturing-wild-lactobacillus/I have run my scotch mash after such an infection with absolutely no difference from the same mash without the infection see here
http://www.aussiedistiller.com.au/viewtopic.php?f=17&t=9632There is a very simple way to avoid a lactobacillus infection, just boil your wort prior to fermentation, should be at a rolling boil for at least 30 minutes to kill all the nasties, the trick then is to cool it to fermentation temperature as fast as possible and pitch a good healthy amount of yeast.
Another observation is that distillers (and bakers) yeasts like to ferment in the high temperature range they can easily go up to 90°F this only promotes the lacto taking hold (lacto likes around 115°F). Here's another good site on lacto souring
http://sourbeerblog.com/fast-souring-lactobacillus/ How about trying a fermentation with a yeast like Safale US05 at around 65°F, it will take at least a week, maybe 2 the ferment out, hopefully the temperature will be low enough that the lacto will not get going.
I ran a wash yesterday that was 100% Cherry smoked gain, mashed on June 8th SG was 1.055, fermented with Mangrove Jack M27 at 90F after 3 days the fermentation was complete at 0.995. it sat as I didn't have time to run it. at around day 5 it started to get the white film on the surface, by yesterday (18 days) it was a thick coating, I just siphoned the wash out from underneath it and ran it. ended up with 2 litres of 70% product and 1 litre of 60% fients. Tastes great!!