Welcome to the wonderful world of sourdough! You will have received a 10g packet of dehydrated sourdough starter, and the instructions below will walk you through how to rehydrate it to full strength in less than a WEEK! The shelf life of your dehydrated sourdough starter can be YEARS (if stored in a dry and cool place) HOWEVER I always recommend reactivating it within a few weeks of purchase! The longer you wait, the longer it may take you to reactivate it. 


  • A large, wide mouth glass jar with lid or paper towel and elastic
  • Wooden spoon or small spatula for stirring 
  • Kitchen scale
  • Unbleached all-purpose flour
  • Water (preferably filtered)

NOTE 1: there is 10g of starter in your packet, however the steps below only require 5g. This is in case you have a difficult time rehydrating your starter the first time and need to give it another shot. So, there is enough starter in your packet to try twice! If you try twice and are following all the steps but are still having issues with reactivating it, please email me at and I will send you a replacement packet.

NOTE:  starter grows best and quickest in a warm environment (ideally 24°C/76°F). If your kitchen is naturally colder, especially in the colder months, then let it sit in a warm spot such as in your oven with the oven light on. This is also why it’s best to use warm (NOT hot!) water in the steps below.



  1. Rehydrate: Place about 5 grams of the dehydrated sourdough starter into your jar. Add 30 grams of warm water to the dry mixture and stir until the starter is completely submerged in the water. Cover loosely and let sit at room temperature for two hours, stirring occasionally during that time.
  2. Feed: After a couple of hours the starter is dissolved and stirring will allow the mixture to become fairly smooth. Add 20 grams of unbleached all-purpose flour and stir until thoroughly combined. Starter should now be the consistency of thick pancake batter (a thinner, more hydrated starter is what allows for increased activity for yeast and bacteria). Cover loosely and let sit at room temperature for 24 hours.
  3. After 24 Hours: Your mixture will look smooth but not lively. Little to no bubbles will be present. But don’t be discouraged! It will still take a few more feedings to bring it back to life (and remember that kitchen temperature effects how quickly this can happen). You will now mix together 10 grams of your starter mixture (discard the rest), 25 grams water, and 25 grams flour in the glass jar. Mix thoroughly, cover loosely, and let sit at room temp for another 24 hours.
  4. Continue feedings: You will continue to feed your starter every 24 hours as it sits at room temperature. Keep using the same ratio: 10 grams starter (discard the rest), 25 grams water, and 25 grams flour. Remember to always aim for the consistency of thick pancake batter, so if you need to add a little bit more water that’s ok. Keep an eye on your starter throughout the process, usually around day 3 or 4 you will begin to notice many small bubbles on the surface and sides which means it’s slowly reactivating. (I like to use a rubber band around the glass jar to mark the level of the starter at each feeding. This makes it easy to measure how much it is rising!) It will soon reach a point where it nearly doubles in size and contains lots of small and big bubbles, and that’s when you know it’s reached peak activity! It will also smell sour and ripe, and yeasty. To test your starter at this point, you can drop a small dollop of it into a glass of water. If it floats then it’s ready to be used for your first recipe!
  5. Next Steps: After your starter has doubled in size you have the option to either a) use it in a recipe, b) store it on your counter and repeat steps every 24 hours to discard and feed it, or 3) store it tightly sealed in your fridge and remove it once a week for feedings. If you store it in your fridge: Make sure you take it out once a week, let it reach room temperature, then feed it as you have been in the steps above. Then wait for it to rise and either use in a recipe or place it back in the refrigerator until you’re ready to use it or feed it again!
  6. Maintaining your SourJo: Firstly, feel free to rename it. Now that you’ve brought it back to life, it’s your baby so you may as well ;) And now that it’s alive you want to ensure you KEEP it alive. Since it’s an active yeast you need to make sure it is receiving regular feedings. The amount of sourdough starter you need for a recipe will depend on the recipe you’re going to be using it for. For my artisan bread recipe, for example, you need 1/4 cup of active starter. But other recipes may require 1 cup or even multiple cups. In order to grow your starter to this amount you’ll need to feed it with more water and flour, and not discard the previous amount as you were doing during the reactivation process above. I like to follow a basic feeding ratio of 1:1:1. This means I simply add the same amount of starter, flour, and water together. Sometimes I may add a bit more flour in order to get it back to that pancake consistency. You can also find many other suggested ratios online- there are so many ways to feed it! Again, if you are planning on baking with it often then I suggest storing it on your counter and feeding it daily. But if you choose to bake less infrequently then keep it in your fridge and feed once a week (see step 5). The time of day you feed it also depends on when you are hoping to bake with the active starter. Remember, once you feed it it will take several hours for the starter to actually double in size (and that is the prime time to use it in a recipe!). Recipes will typically instruct you on when to feed it, but I have always found that doing it between 4-6 hours before making my dough works best for me. 

Having a hard time reactivating your starter or have general questions about SourJo? Scroll to the bottom of this page for answers to all FAQ’s!

For more sourdough tips and tricks, recipes, and more be sure to follow me on Instagram at @jotiwall. Email with any questions. And please be sure to tag me in all your posts because I’d love to see them! :)