This attempt to re-start with starters failed-nothing happens in tanks, I checked every day for last 7 days.
When I made starters (4 bottles described and visible above), activity was obvious but lot smaller (lot smaller foaming) than on Bryan's photos.
That made me suspect-perhaps my EC-1118 are old and outdated. I checked-it reads BBD: 05.2024, so probably not the case.
Unless I bought some dodgy batch, if that ever happens.
Is that possible that airports nuking (X-Ray) damaged dried yeast ? - no idea.
Not even sure if they do that with commercial freights.
And so yesterday I made another experiment:
I got one liter from tank (SG=1.03, bloody sweet), added 0.5 ltr water, applied 100grams Dextrose (glucose)+10 grams EC1118+5 grams nutrient.
I did not put much attention to temperature, it was about 20C last evening, then dropped below 20C at night, now slowly growing to 20C or so.
Something very minor happens there, very slowly (photo attached).
I am not sure what to do next, maybe I should put this "wine based starter" into one of tanks (with 25 liters of bloody sweet) and see what happens ?
My general thoughts-conclusions are:
I do not know how strong (alc %) is my bloody sweet (150 liters of it) but I think it was strong enough to kill yeast (combined with lot of sugar that also has preserving effect). This would explain why this fermentation got stuck.
I underestimated amounts of sugars in plums used and all together it was simply too much sugar.
Currently I see no other explanation, maybe you can ?
My plans:
Unless some of you, good people, brings some promising new idea, I think I should put my 4 tanks back to 50 liters kegs and let them clear, age for couple months. As I said I do not know alc % but I have reasons to think it is fairly strong wine (that killed yeast ?) and so it should clear/age safely, with minor risk of contamination.
I have foot surgery later this month, which will totally ground me for two weeks (unable to walk) and then I will have to use some moon boot for following 6 weeks-wine will have to rest before I can do anything again.
And later I can dilute it with water (say 1:1), to drop alcohol %, add some concentrated, dark juice and re-start using Bryan's starters again.