How do you keep sourdough starter in the fridge?

Sourdough starter needs to be fed and cared for regularly to keep it alive and active. However, there are times when you may not be baking as often and need to store your starter in the refrigerator for longer-term storage. Here are some tips for keeping sourdough starter in the fridge.

Why refrigerate sourdough starter?

Refrigerating sourdough starter slows down the fermentation process, allowing you to keep it alive for weeks without having to feed it as frequently. This is useful when:

  • You are going on vacation or will be too busy to bake for a while.
  • You bake infrequently and don’t need active starter on hand.
  • You want to pause starter production but keep your culture going.

The cold temperature of the refrigerator dramatically slows the yeast activity in your starter. This puts the starter in hibernation mode so it requires less frequent feedings to stay alive.

How to store sourdough starter in the fridge

Follow these steps to properly store your sourdough starter in the refrigerator:

  1. Feed the starter as usual and allow it to peak, usually 4-8 hours after feeding. You want an active, healthy starter before refrigerating.
  2. Pour off and discard most of the starter, leaving just 1/2 cup (120ml) in the jar.
  3. Mark the level of the starter on the jar so you know how much to feed it next time.
  4. Seal the jar tightly and refrigerate.

It’s important to refrigerate an active, peaked starter. This ensures there are plenty of yeast and bacteria to keep the culture alive in the fridge over time.

Choose the right container

Use a clean jar or container with an airtight lid to prevent moisture loss. Glass and plastic are good options. Avoid reactive metals like aluminum. Ensure at least 1/2 cup of room temperature starter is left in the container before refrigerating.

Mark the level

Note the level of the starter before refrigerating. Over time, hooch (clear liquid) will accumulate on top as the yeast becomes dormant. When feeding again, pour off the hooch and return the starter to its original level before adding the fresh flour and water.

How long does sourdough starter last in the fridge?

Properly stored, sourdough starter can last 2-4 weeks in the refrigerator without needing to be fed. However, most bakers recommend feeding once a week to keep it healthy and active.

Here are some signs your refrigerated starter may need a feeding:

  • A layer of hooch (clear liquid) has accumulated on top
  • It has a strong alcohol smell
  • Bubbles or rise are minimal after feeding
  • It has been 3-4 weeks since the last feeding

If your starter shows these signs, take it out of the fridge, pour off the hooch, and feed it 1:1:1 with flour, water and existing starter. Let it double in size at room temperature, then refrigerate again.

How to feed refrigerated sourdough starter

To feed your refrigerated starter and return it to an active state:

  1. Remove starter from fridge and let warm up to room temperature for a few hours.
  2. Pour off any hooch (clear liquid) on top.
  3. Return starter to its original marked level by discarding excess.
  4. Add equal amounts flour and water to remaining starter, mix, and let sit at room temp.
  5. Wait 8-12 hours for starter to become active again and double in size.
  6. Use in baking or store in fridge again.

For example, if you have 1/2 cup of refrigerated starter, add 1/2 cup flour and 1/2 cup water. Mix and let sit out until bubbly and risen, then refrigerate again.

Tip for fast activation

If you need your starter active and ready to bake with faster, try doing a couple feedings 2-4 hours apart to wake it up more quickly.

What to do if refrigerated starter is neglectedy

Sometimes life gets busy and your refrigerated starter may go a few weeks without a feeding. Here’s what to do:

  1. First, check for signs of mold. Mold means the starter is no longer usable.
  2. Smell the starter. A very strong alcohol smell means much of the starter has died.
  3. Look for small bubbles after feeding, indicating remaining yeast activity.
  4. Discard 90% of starter and feed remaining 10% as if new.
  5. Repeat additional feedings over 24-48 hours to revive and rebuild.

With tender loving care, you can often rescue neglected starter. But if mold, putrid smells, or no bubbles appear, it’s best to discard and begin again with new starter.

Tips for storing sourdough starter in the fridge

Follow these tips for best results storing your sourdough starter in the refrigerator:

  • Mark the starter level – This allows you to return to the right amount when feeding again.
  • Leave room in the jar – Prevent starter overflow by leaving at least half the jar empty.
  • Use airtight containers – This prevents moisture loss and contamination while storing.
  • Feed weekly – Frequent feedings keep refrigerated starter healthy.
  • Revive properly – Let starter wake up and grow active at room temp before refrigerating again.

Common problems and troubleshooting

Here are some common problems that can occur with refrigerated sourdough starters and how to troubleshoot them:

Starter grows mold

Cause – Contaminated container or exposing starter to air during storage can introduce mold spores.

Solution – Discard starter. Sterilize container. Start fresh starter from scratch.

Starter separates into layers

Cause – Excess water content causes liquid hooch layer to separate.

Solution – Pour off hooch and stir before feeding. Maintain proper starter consistency.

Starter smells like strong alcohol

Cause – Overfed or neglected starter has fermented too much of its sugars.

Solution – Discard 90% and rebuild with several feedings over 24-48 hours.

Starter isn’t rising after feeding

Cause – Yeast have become inactive during storage.

Solution – Wake starter up with a couple vigorous feedings before refrigerating again.

Frequently asked questions

Should sourdough starter be covered in the fridge?

Yes, always cover starter stored in the refrigerator. An airtight lid or plastic wrap prevents contamination, moisture loss, and odor absorption from other fridge contents.

Where in the fridge should I store my starter?

The main fridge compartment is ideal, where the temperature is consistently cold but above freezing. Avoid freezer, produce drawers, or door shelves where temperature fluctuates.

Can I store my starter longer by chilling it further?

No, freezing or over-chilling starter can harm the microbial balance needed to keep it healthy. Store at standard fridge temperatures between 34-40°F (1-4°C).

Should I take my starter out of the fridge before feeding?

Yes, always bring refrigerated starter back to room temperature before feeding. This activates the yeast and bacteria so they can grow. Feed at room temp, then return to fridge.

How long can sourdough starter stay out at room temperature?

Fed starter can ferment at room temp for 4-12 hours between refrigeration. Beyond that, the starter needs refrigeration to slow it down and prevent spoilage.


With proper storage and weekly feedings, sourdough starter can keep for weeks at a time in the refrigerator without compromising its health and leavening power. Pay close attention to signs of neglect like hooch separation, strong odors, minimal rise, and mold growth. Discard severely compromised starters and begin anew. With a little TLC, refrigeration lets you presses pause on your sourdough culture while still keeping it viable for future baking.

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