How to Freeze Sourdough Starter: A Step by Step Guide
Learn how to freeze your sourdough starter for easy, long-term storage. Preserve your starter for future baking and ensure you always have a healthy, active culture on hand!
Sourdough is rising in popularity and for good reason! This old age form of bread making requires no commercial yeast and is made of only 2 ingredients: flour and water.
Sourdough is not only simple to make, but it is delicious. The unique tangy flavor and texture of sourdough is absolutely delightful, however, if you are regularly feeding your sourdough starter you may end up with more starter than you can use.
Instead of letting it go to waste, freeze it! In this post we will cover reasons you might want to freeze your sourdough starter and go through the simple process in a step by step guide on how to do it easily.
Why is Sourdough Good For You?
Sourdough bread contains gut healthy bacteria called lactic acid bacteria. Lactic acid bacteria are beneficial microbes that play a key role in supporting gut health. These bacteria are also responsible for the fermentation process, producing the signature tangy flavor and helping the dough rise.
As probiotics, they help balance the gut microbiome by promoting the growth of good bacteria and inhibiting harmful pathogens. These beneficial probiotics also aid in the digestion of food and enhance nutrient absorption, particularly for minerals like calcium and magnesium.
Additionally, they produce organic acids, like lactic acid, that help maintain a healthy pH in the gut, which supports optimal digestion and strengthens the immune system. Including foods like sourdough in your diet can help improve overall digestive health and boost immunity.
Can You Freeze Sourdough Starter?
Yes, you can freeze sourdough starter! When sourdough starter is frozen, the cold temperature slows down or temporarily halts the activity of the lactic acid bacteria present in the culture.
Freezing doesn’t kill the bacteria but puts them into a dormant state, essentially preserving them for later use. When the starter is thawed, the beneficial bacteria “wake up,” and with some regular feeding, they quickly become active again, resuming their work of fermentation.
While freezing may reduce the overall number of bacteria slightly, a healthy starter should bounce back just fine after a few feedings, ensuring that it remains potent for future baking.
Why Should You Freeze Your Sourdough Starter?
Freezing is a great way to preserve your starter if you’re taking a break from baking bread for an extended period of time or if you have a lot of extra starter and you don’t want it to go to waste. You can use frozen discard in any sourdough discard recipe, or start a brand new starter with it!
Long-Term Storage:
If you’re going on an extended vacation or just need a break from regular baking, freezing is a great option.
- If you will be gone for an extended period of time or are taking an extended break that will be longer than 4-8 weeks, freezing or dehydrating your starter will yield the best results.
- For shorter trips: Sourdough starter can last several weeks in the fridge in a glass jar or air tight container with a tight fitting lid.
Prevent Waste:
If you’re not baking frequently, freezing helps you keep your starter alive without the need for constant feedings.
- If you have extra sourdough discard that has accumulated from frequent feedings, freezing some is a great way to preserve it for later use.
Backup:
The best way to ensure you always have an active healthy starter is to prepare a backup. It’s always good to have a backup in case your active starter is accidentally thrown away, accidentally cooked in a preheating oven (happens to the best of us) or gets contaminated with mold or kahm yeast.
- There are many reasons you might find yourself without an active sourdough starter, most of which involve human error—like forgetting you left your starter in a warm spot, such as the oven with the light on, to help it rise faster. Then, when you preheat the oven for dinner, you realize you’ve accidentally baked your starter and killed the wild yeast in it. For this reason, it’s always best to have a backup! I call it my “sourdough insurance” policy.
- I recommend freezing or dehydrating sourdough starter when you have extra to make sure you always have some on hand. I personally like to keep multiple forms of back up sourdough starter on hand at all times because my family can’t live without our sourdough favorites like tortillas, bagels and biscuits.
How to Freeze Sourdough Starter
Step 1: Prepare Your Starter
Before freezing, make sure your starter is healthy and active and has been fed recently. This ensures that the wild yeast will have something to feed on and allow them to proliferate before going into “hibernation”. Feed your sourdough starter a day or two before freezing to ensure it’s nice and bubbly and strong. Here’s how you can prepare your sourdough starter for the freezer:
- Feed Your Starter: Discard at least half of your starter and feed it with equal parts flour and water. Note: I do not personally use a kitchen scale for feedings to measure grams of water and grams of flour precisely, unless I’m recipe testing. I add fairly equal parts of unfiltered water and all purpose, unbleached flour to my starter and mix until a thick batter like consistency forms.
- Cover and let it sit at room temperature for 8-12 hours until it’s bubbly. The time this process takes is highly dependent on the temperature of your home. Warm temperatures (above 70-71) will cause the starter to rise faster, cooler temperatures will slow down the activity and make the starter rise much more slowly.
- Check for Activity: Your starter should be full of bubbles and doubled in size (or close), indicating that it’s at its peak.
Step 2: Portion Your Starter
Once your starter is active and at it’s peak, decide how much sourdough starter you want to freeze. It’s helpful to freeze it in smaller portions so you can thaw only what you need later.
A good portion size is around 1 cup, but you can choose smaller amounts if you prefer. I like to use silicone molds like Souper cubes that are already portioned into 1 cup portions for easy freezing and thawing, but any airtight container or freezer bag will work.
Step 3: Pack for Freezing
- Choose Your Container: Use airtight containers with a good fitting lid or freezer bags like a freezer safe ziplock bag.
- Label the Containers: Write the date and amount on the container or plastic bag. It helps to keep track of how long it’s been frozen.
If using plastic bags, fill them and then lay them flat on a baking sheet to remove as much air as possible to prevent ice crystals and freezer burn. Allow them to rest on the baking sheet until frozen solid so that the plastic bags of frozen starter are thin and take up less space in the freezer.
Step 4: Freeze
Place your labeled containers in the freezer. Make sure to note the date so you can use it within 6 months. The cold temperatures of the freezer put your starter into a “hibernation” and dramatically slows the activity of the wild yeast.
Since the starter was fed before freezing, the yeast will have plenty of energy to survive during this hibernation period for up to 6 months. For the best flavor and viability try to use it sooner, within 3 months.
If you decide to go longer than 3 months just keep in mind that starter frozen between 3 and 6 months will take longer to “wake up” after this period of hibernation and may require more work and feedings to get back to normal.
How to Thaw and Revive Your Frozen Sourdough Starter
When you are ready to bring your sourdough starter back to life, follow these three steps:
- Thaw in the Fridge: Take the container out of the freezer and place it in the refrigerator overnight to thaw.
- Bring to Room Temperature: Once the sourdough starter is thawed, let it sit at room temperature for a few hours covered.
- Discard and Feed: Discard half of the starter and feed it with equal parts all purpose flour and water. There is no need to measure this, just add approximately 1 part water to 1 part flour and stir until the consistency is like a thick paste. Let it sit at room temperature for 4-6 hours. Repeat this process of discarding and regular feedings for a few days or until your starter is bubbling and active again.
Final Notes:
Just like keeping a dried starter, freezing your sourdough starter is a great way to make sure you always have sourdough starter to bake delicious homemade bread. This is a great way to make sourdough baking fit your schedule so you can take a break from baking anytime you want.
Be sure you start the freezing process with a mature sourdough starter to make sure it is healthy enough to withstand long term storage in the freezer. It’s a good idea to use a starter that you have been regularly baking with for a few months before attempting to keep it in the freezer for a long time.
If you make sure to keep track of how long your starter has been frozen or dehydrated and use it in a timely manner, you can be sure it remains alive and healthy indefinitely!
