Unsuccessful creating Lievito Madre

I've been working from this recipe - Ricetta Lievito madre - La Ricetta di GialloZafferano

I made a few modification based on what was available. So Instead of Farino 00 and Farino Manitoba, I started with Whole Wheat flour because it was unused and going to waste so I thought I might as well use it up to make the starter. My plan was to slowly at each feeding to reduce the amount of whole wheat flour while introducing bread flour into the mix until the whole wheat flour was eliminated.

Everything else was as in the recipe including starting with the blended soaked raisins and feeding every 48 hours.

I also cut the recipe in half at subsequent feedings to reduce waste.

My problem is that the starter smells so bad like acetone / nail polish remover. So strong. Then at my recent feeding today the surface of the ball of dough had formed what looked like mould (fuzzy stuff) all over it.

It was at that point that I tossed everything in the garbage.

I started April 19 and ended today (April 25) so that was only 3 feedings/refreshments.

Honestly I'm thinking of going back to 100% hydration starter for regular sourdough because that is the only successful starter I have ever made. Every time I try to make a 50% hydration starter it ends badly.

Did your raisins have sulphur dioxide on them? If so, that might have had an effect on fermentation. Although it is an interesting idea to use raisins, since grape skins naturally have yeasts on them.

Any regular sourdough starter can be used to make lievito madre. It does take time though.

Le fermentazioni spontanee by Di Cristo, Marinato et al, is an interesting book on using non-flour ingredients in starters. I have not had a lot of luck with this approach, and my LM is just flour-based.

Otherwise, Hamelman has a raisin based, 63% hydration starter in his "Swiss farmhouse bread" recipe that could be worth investigating?

Imo you have 2 choices:

You can use your sourdough starter (100% hydration) as a “starter”. I assume it’s active and dourbles or triples in volume in 3-5h depending on the feeding ratio and temp. Change the flour / water ratio to 2 / 1 for the next few days. After a few feedings 1:1:0.5 (starter:flour:water) your overall hydration will be 50%. The volume should triple in 4.5h at 27C. Now you can start with the warm/cold cycles and reduce the hydration to your target hydration (40%-45%). It will take probably 2 weeks until you have a full developed and balanced LM, but I’m pretty sure it’s faster than from scratch.
You can choose another method to create an LM. I used for the first step a mix of 50g wholemeal rye flour and 50g water, 48h at 24C. After 48h feed every 24h 50g from previous day with 50g white flour and 25g water. Temp After 5-7 days you should see a pretty good activity, the volume should double to triple. From here you continue like above.

A few important things when you work with LM, specially at the beginning:

Stable conditions, specially temp. are key.
Cover the container/jar/etc to minimize possible contamination with unwanted microorganisms from the environment. Especially in the first days the LM is not very stable.
Before feeding clean everything (tools, container, bowl, hands, etc) very good. Make sure there are no diswasher liquid or soap residues.