Some time ago I have grown my own sourdough starter fed with 50/50 wholemeal rye & all-purpose wheat flour (with 100% hydration). It turned out great, it normally grows a bit over 2x in volume after feeding over night, and smells in a pleasantly floral way.
I had this idea, that with already established yeast culture, I could now start a second jar, where I would grow 100% all-purpose wheat flour with a bit of the 50/50 starter - so that I would end up with a fast wheat sourdough starter. I have started it last Sunday, and I could see activity in it already after 24h, with a visible volume increase (~maybe 1.5x?) and a bubbly surface. However, after I gave it a sniff after these first 24h, I immediately detected a really offending smell, which brought about association with still water in nature, like the one you can smell in swamps. I figured it might be a result of a rapid flour type change, and that new microorganisms have started multiplying in there in competition with the already established yeast culture, so I just chucked out most of it, and fed the dirty jar with a new feed of all-purpose wheat. This morning the smell is back, maybe in a slightly smaller intensity, and volume growth is around 2x already. No mold can be seen on the surface, and the color of the mixture is milky-white.
Can anyone with some experience in this area tell me, if that is a normal behaviour, with all-wheat starter just going through its kiddy-years at the moment? Or did I already mess it up, and the only real choice is to chuck it and start anew?