That was a super inspiring read, thank you! I've been wary of keeping starters going for long, expecting them to foam their way out of the bottle before I have a place to put them. Next time I'll make the starter first thing on brew day. Watching these processes is a great way to learn and get a feel for things, and I never get to see what happens in the steel fermenter. Made the birch sap cava in a plastic container and it was the first time I got to see what happens in the process.
As for the sugary starter solution, I can report that the basic fresh yeast from the grocery store (I'm sure you know Suomen Hiivan tuorehiiva) has thrived in even more saturated starters, I've been going with 1 dl of syrup in 1 litre water before. And the nutrient was just a pinch into the starter. I get that stuff in satchets made to serve 20 litres of wine juice.
Yesterday I made one last try at a starter with the fresh yeast. I kept it for five hours, and it was very much going and foaming when I pitched it. Also put a heater in to keep the insulated fermenter at 23 °C. It's been 18 hours since pitch now and so far it looks like the Moloch in my brew has taken another victim. Oh well, weekend on the way and it looks like Saturday I'll have the house to myself. Looks like a brew day :))
Thanks for the encouraging words :) I guess this one is a goner though, it strangled a fourth pitch of a starter that was certified going strong when I put it in. Even if that stuff did eventually ferment, I'm not sure if I'd dare drink the cursed brew XD
I've been trying different temperatures, too – the setup is not super expensive per se, but it is versatile in that I have the fermenter insulated and can both cool and heat it with an automatic temperature controller (to heat it I borrow wife's hair dryer, it's there now holding 23 °C :D ). My usual fresh yeast is super easy in that regard, I'd normally allow a couple of hours after pitch at the ~25 °C that the wort tends to stand at at that time and then set the thermostat to 15 - 18 °C for the entire bubbly bit, so normally all I need is cooling against heat produced by the yeast.