Never happened before with my neutral wash (I've made about 20 batches). Same recipe.I had the last strip run of my UJSSM do the same thing. Again, after more than 30 batches, it has never happened before.
My still and all lines get a rinse with clean water before every run, and this is always checked for undesirables. It's always clean.
pH of the distillate is 4.3. It's cloudy because I strip to 10%.
The only difference I can point to is it sat a bit longer than normal because I went on a 2 week trip to Van Diemen's Land.
It went dry in 10 days and it then sat for 4 weeks. It usually sits for 10 - 14 days and then I run it. The smell in the fermenter was slightly vinegary (pH 4.4) and slightly sour in taste.
It needs to have a spirit run done, but should I dump it (and the UJSSM) and start a fresh batch. The SM is up to it's 6th gen. I start again after 10.
I've checked other posts for this phenomena, but nothing really nails it down.
scarecrow