I have a new sourdough starter I made about 2 weeks ago. I took it out of the fridge yesterday afternoon and fed it. It was slow to rise and even placed in the oven with light for a about an hour. I checked in the evening and nothing, then forgot about it and went to bed. Next morning it has overflowed. Is it still good, what should I do with it after sitting out for 18 hours? Can I put it in the fridge again and use it in a couple days? Do I need to feed it again before using it to make bread?