Hi Joanne, while the sour smell isn't necessarily a bad sign, the white spots could be mold, so I would recommend starting over and cleaning all your utensils and jar very well with boiling water, if possible, before beginning a new starter. Since your room temperature is so warm, you can definitely use cooler water to feed it (15-21 degrees Celsius). This may help slow down fermentation and (hopefully) prevent the starter from spoiling in future attempts. Barb

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