After another 24h both glasses are already raising. The sourdough started is now active and can be used for baking. I’ll still feed them and let them stand for another day, but in principle this is how it should look and what you need to do.

Finished sourdough in jam glasses. Left: Rye based, Right: Wheat/Spelt based

Sourdough in about 4-5 days from scratch, using nothing but flour and water. Nature provides really everything you can wish for 🙂