As mentioned, to bake we want an active starter. We can assume its active if it has grown in size as mentioned in , but if you are uncertain, you can also do the floating test. It’s also always worth making sure your starter is active enough to leaven your dough. The trick you can use is just to drop a spoonful of starter in a glass of water. If it floats, it’s ready. If not, it’ll produce a dense loaf— just feed it again, or wait a bit, if you’ve just fed it.