Rehydration Instructions

Reviving Your Dehydrated Sourdough Starter

Please read this entire page before you begin. Helpful tips and troubleshooting notes are included at the bottom.

If you’re having trouble, or think your starter is dead, inactive, or not working, please reach out to us before leaving a review. We see this from time to time, and it’s almost always due to one of a few common environmental variables that can be quickly identified and easily fixed. 

(Updated 1-13-2026)

Let’s Get Her Bubbling Again

What You’ll Need:

• A 16 oz glass jar and a larger jar (32 oz ) for expansion by Day 5 ( Ball jar with lid is ideal )

• Filtered tap or spring water (avoid distilled, purified bottled, or reverse osmosis water)

• Unbleached bread flour ( preferred ) or all purpose flour is acceptable ( or Gluten Free flour of your choice )

• A mixing utensil (avoid metal) and a kitchen scale (Not essential but VERY important for baking)

 

Helpful Tips before starting:

Try to begin the process in the morning so your starter reaches its most active state during the day. A mature starter typically peaks 4–6 hours after feeding. If you start in the evening, it may reach its peak overnight, making it less convenient for baking. When a starter hits its peak, it tends to rise and then collapse back down. At this stage, a strong smell and watery texture are normal signs that it’s hungry and ready for the next feeding.

If at any point the mixture becomes too warm or you see bubbles rising to the surface, add more flour and just enough water so that there are no dry flour pockets - the thicker, the better. A thin, watery mixture will cause bubbles to rise and burst at the surface, which can hinder the starter’s ability to rise and will give the appearance of the starter not being active. This is the number one problem beginners encounter, especially in summer months. In the winter or cold environments we see the opposite, slow activation due to cold temperatures, please use water between 75-85 F ( 24-29 C ) for any feeding and feel free to use a digital meat thermometer or similar to take the internal temperature of your starter at any point to make sure it stays in the “Sweet Spot”

Keeping the starter elevated off of granite or cold surfaces helps a lot. You may use any type of external heating source to maintain your starters ideal temperature, but do not let it get too hot. Some things you may have around the house to use are items like a garden seedling heat mat, top of an espresso machine, top of the refrigerator, in the oven with only the oven light on ( Some oven lights are much too hot for this ) - You may also use ceramic dinner plates or similar to stack on top of any of these heat sources to dissipate the extra heat if they are too hot ( espresso machines, etc )

Day 1:

Empty the contents of one packet of dehydrated starter into your glass jar. Add 30 Grams ( 2 tablespoons) of warm water and stir. Let it sit for an hour. After that hour, add 15 Grams ( 2 tablespoons) of flour. It’s okay if the starter doesn’t fully dissolve. Stir until all the flour is incorporated and no dry patches remain. Cover loosely and leave at room temperature for 24 hours.

Day 2:

After sitting for 24 hours, it’s time to feed the starter for the first time. USING WEIGHT IS ALWAYS PREFERRED. Add add 15 Grams ( 2 tablespoons) of flour and add 15 Grams ( 1 tablespoon) ( Equal weight of one part flour and one part water, are roughly equal to a ratio of 2/1 by volume ) of warm water. From this day forward, the final consistency goal after feeding is a very thick paste ( difficult to stir ) that holds a blob / ball shape after stirring, it will settle in the jar after sitting for 30 minutes or so, if the starter is more runny / thin / pancake badder than described here, add a touch more flour to the mixture. Stir well, cover loosely, and leave at room temperature for another 24 hours.

Day 3:

Add add 30 Grams ( 4 tablespoons) of flour and add 30 Grams ( 2 tablespoons) of water. By now, you may see the beginnings of bubbling activity—your starter is starting to come alive! After mixing and feeding, cover it again and leave it for another 24 hours. Look for more bubbles and some volume increase in the jar.

Day 4:

You may notice the starter has grown and then fallen, leaving streaks along the sides of the jar. This is a good sign! Today it’s time for a more substantial feeding. Mix in 60 Grams (½ cup) of flour and 60 Grams (¼ cup ) of water. If the texture seems too thick, as long as there are no dry pockets of flour it should be perfect. (Environmental factors can slightly change how much water is needed.) Stir thoroughly, cover loosely, and let it rest for another day. If the jar is getting full, transfer the starter to a larger container.

 

Day 5: Time to Prep for Baking!

If you haven’t already, now is the time to transfer your growing starter into a larger container, something in the 32 to 64 oz range works well depending on how much starter you plan to maintain. Please weigh and write on the jar the weight so that you will know how much starter remains in the jar after you discard later on in the process. 

For today’s feeding, mix in 60 Grams (½ cup) of flour and 60 Grams (¼ cup ) of room temperature or slightly warmer water. If the mixture feels too thick, slowly add water by the teaspoon until it resembles a thick paste.

Keep your starter in a warm spot (ideally between 70–80°F or 21–27°C). Within 4 to 6 hours, you should see noticeable rising and bubbling. In cooler environments, this may take longer or need assisted heat, and your starter might need additional feedings to become fully active.

Once it doubles in size within that 4–6 hour window, it’s officially ready to bake with ( See website for bread / other recipes, everything on this page is starter care only ). Starting tomorrow, you’ll follow a regular feeding routine to maintain your healthy starter.

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Ongoing Starter Care (Day 6 and Beyond)

Room Temperature Maintenance:

If you plan to keep your starter at room temperature, it will need daily feedings. Before each feeding, discard enough starter so only about ¼ of the jar remains. (Save the discard in a separate container for use in recipes - just don’t pour it down the sink, it will clog!)

Feed by adding equal parts of flour and water by weight to match the remaining starter in the jar. This is typically a 1:1:1 ratio of starter, flour, and water. Aim for the same thick, batter-like consistency. You can measure by eye or use a scale for more accuracy. If your starter seems too thin and bubbles are rising to the top and popping easily (which prevents the starter from rising / doubling), feed a heavier flour ratio like 1:3:2.

Refrigerated Maintenance:

If you bake less often, you can store your starter in the refrigerator. Make sure to tighten the lid. Feed starter before refrigerating, and then feed it again every 7–10 days.

When ready to use starter again:

1. Remove starter jar from the fridge, discard excess starter if needed ( see discard instructions above).

2. Feed starter with equal weight of flour, and water. ( Example: 60 grams of starter already in jar, add 60g water, add 60g flour ) 1:1:1 ratio or 1:3:2

3. Return starter to the fridge, or if you plan to bake, leave starter out and feed it for 1–2 days until it’s active and doubling in size after 4-6 hours of feeding.

Be sure to feed the starter before you plan to bake so it’s nice and bubbly and at its peak when you use it in a loaf!

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Congratulations!

You’ve now got a fully active and ready to use sourdough starter! Give it a name, it adds to the fun.

Visit GRTgrandmas.com for recipes, information, videos and additional support.

• If you do not plan to use your starter daily, you may refrigerate it and feed it weekly. A healthy starter can remain in hibernation in the fridge for up to a month or more without feeding ( every week is optimal but not necessary).

Important Notes:   -

The most common issue we see is a mixture that’s too thin and runny. Don’t worry - just add more flour to thicken it (see notes below). Variations in environment mean recipes may need small adjustments. The second most common is that the starter is too cold.

• Your starter is very resilient. If you think it’s dead ( extremely rare ), email us for support before discarding it.

• Some starters may require twice-daily feedings during activation, especially after Day 4. ( especially when using low protein percentage flour)

• If liquid (called “hooch”) appears on top, simply pour half of it off or stir it back in and feed the starter well. This is normal and means everything is going according to plan.

• Never throw your starter away without trying to revive it with a feeding. ( Usually, the starter has used it’s available nutrients and is hungry )

A typical feeding ratio is 1:1:1 (starter : flour : water), but this can be adjusted, some prefer a 1:3:2 ratio. If your starter seems sluggish, feed it more. If your starter seems too thin and bubbles are rising to the top and popping easily, feed a heavier flour ratio like 1:3:2

Remember that reviving a dried sourdough starter can take time and patience, so don't be discouraged if it takes several days for your starter to become fully active. Also there are many factors in home baking without professional equipment and each batch will come out more or less sour, dense, proofed, amount of holes, etc. So spend time researching what makes each of these characteristics happen ( See our website for information) and try to dial in all input levels and variables, It’s a life long journey to master the art of the perfect Sourdough. Enjoy!