Good question, Alec! If your starter is doubling in volume, it's considered active. The time it takes to reach that peak will vary from starter to starter. While 6-8 hours is most common, 12 hours isn't that abnormal. You'll just want to take that into account when you're feeding your starter in preparation to bake. If you intend to start making your dough at 8 pm for an overnight rise, you'll want to feed your starter at 8 am, rather than noon. Happy baking! 

• Reply