Rehydrating Your Sourdough Starter
Mix: Pour your dehydrated starter into a clean jar with about 1/4 cup room temperature water.
Stir: Stir the starter and water until most of the starter is dissolved. It's okay if some of the larger flakes remain.
Let it sit and stir: Let the mixture sit for a few hours and stir every hour until the mixture is fully dissolved and smooth.
Feed: Add a 2:1 ratio of flour to water to the rehydrated starter. If your jar is large enough, you can feed with 1/2 cup of flour and 1/4 cup of room temperature water.
Discard and Feed: You will need to repeat the feeding process until your starter becomes bubbly and rises by double the amount in about 6-12 hours. Because you may have to feed a few times before the starter is completely active, you will need to discard some of the starter so it doesn't overflow the jar. Note: there are a lot of discard recipes you can find online, or you can dump in the trash. Do not pour discard down the drain to prevent clogs!
Bake: When the starter is doubling after a feeding in about 6-12 hours, you are ready to try out any recipe that calls for an active starter.
Temperature greatly affects the speed by which a starter doubles and rehydrates.
During the winter months, this process will likely take longer than during the summer.