How Long to Proof Sourdough in the Fridge (+ Tips)

You’ve mixed your dough, completed your stretch and folds, shaped the dough, and put your soon-to-be-baked dough in a banneton basket.

Now, it’s time to pop that uncooked sourdough loaf in the fridge for the last step: cold proofing (also called cold fermentation).

How long does your dough need to stay in the fridge before you bake it? I’ve seen recipes call for just 2 hours while others swear by many days.

Let’s talk about it.

Quick Vocab Moment

There are a lot of terms here that mean the same thing. So before we proceed, here’s a quick vocabulary lesson:

Cold retard, second proofing, final proofing, cold fermentation, cold final proof, and cold proofing all mean the same thing: after final shaping, your dough chills out in the fridge.

The low temperature of the fridge really slows down the fermentation process, which is why it’s often called a cold retard (retard means slow down).

The Purpose of Cold Fermentation

After you finish your bulk fermentation and shape your dough, why can’t you bake that dough right away?

The short answer: you can skip cold proofing. That would allow you to have same-day sourdough bread.

But putting your shaped dough in the fridge for a while offers a lot of benefits, which is why most of us don’t skip it:

• More complex flavors develop, including those classic sour and tangy notes
• The dough is much easier to score as it firms up a bit, ideal for those interested in intricate, artistic scoring designs
• The yeast breaks down more of the gluten, making the bread easier to digest – really helpful for those sensitive to gluten
• The gluten break-down also leads to a lighter, more airy crumb
• Practical for scheduling purposes – you can shape your dough and have ready-to-bake sourdough in your fridge at all times (why wouldn’t you want to be the boss of bake time?!)

Cold Fermentation and Overproofing

Bulk fermentation, or when your dough strengthens and rises the most, happens at room temperature.

When you put your shaped dough in the fridge, it’s still fermenting but at a much slower rate (like 10x slower).

That’s why many bakers refer to this time in the fridge as a second rise or final rise.

While the dough isn’t rising very fast, it’s still happening, so there’s a risk of overproofing if you let it go too long. Overproofed dough gets dense and flat, so we definitely want to avoid that!

In my experience, I’ve only had over-proofed sourdough due to cold proofing when I left the dough in the fridge for almost five days.

The Poke Test

To tell if sourdough dough is properly fermented, some people use the “poke test.”

• Underproofed dough: springs back quickly
• Properly proofed dough: springs back slowly
• Overproofed dough: never springs back

However, the poke test will not work during or after a cold retard. The poke test for sourdough is only reliable before you put that dough into the fridge.

Ideal Cold Proofing Time Frame

In my experience, my sourdough bread has the best results when I do a cold proof that lasts between 12-36 hours.

As I mentioned earlier, I recently did a cold proof (accidentally) for nearly five days or around 115 hours, and my dough was over-proofed.

I’d let your cold fermentation go at least 12 hours to enjoy all of the benefits I mentioned earlier, like more complex flavor, easier digestion, lighter crumb, etc.

Two hours is the minimum amount of time to enjoy some of the benefits of cold proofing. But honestly? With that short of a timeframe, I think your only main benefit would be that it’s easier to score.

Sourdough is a slow process, and only two hours at cooler temperatures won’t do much.

Cold Fermenting and a Flexible Sourdough Schedule

Use cold fermentation to your advantage, and you’ll be the boss of your bake times.

I always make a double batch of sourdough – there’s just no point in going through all of that effort for a single loaf of bread (in my opinion).

But the beauty of making a lot of dough at one time is you don’t have to bake it all right away. We all love fresh bread, and you can have fresh bread multiple times a week by taking advantage of the fridge’s cold environment.

Here’s a sample schedule:

• Friday night: feed your sourdough starter.
• Saturday: mix your dough, stretch and folds, pre-shape, shape, pop in the fridge.
• Sunday: bake a loaf of sourdough.
• Monday or Tuesday: bake another loaf sourdough.
• Wednesday night: feed your sourdough starter and start the process all over again.

Cold Proofing Tips

I’ve learned a few things about cold proofing over the last year of sourdough baking and experimenting. Sourdough is such a slow burn of knowledge, so I’ll continue updating this post with more tips and information as it comes.

• A super important step is covering your banneton in plastic wrap or (my preference) a bowl cover. Without that, the surface of your dough will dry out, leading a tough exterior.
• Find your own sweet spot by experimenting with different cold retard timeframes. If I’ve learned anything about sourdough, it’s that everyone’s environment is different.
• If you’re sensitive to gluten, push the cold retard as long as you can. I’d recommend trying to let it rest for up to three days, or 72 hours.

You Might Enjoy: 282 Best Sourdough Starter Names: Ideas & Inspiration

Proofing Sourdough In the Fridge FAQs

Here are the most common questions I’ve seen about how long to proof sourdough in the fridge.

How long do you cold ferment sourdough?

I’ve found a cold fermentation of 12-36 hours is ideal. I’ve only seen issues (namely over-proofing) occur after four days, or 96 hours, in the fridge.

How long can you cold ferment sourdough?

You can cold ferment sourdough without any issues up to three days, or 72 hours. For those with gluten sensitivities, I’d actually recommend a long cold fermentation like this. It’ll also yield a more complex, tangy flavor profile.

How do you cold ferment sourdough?

To cold ferment sourdough, you place your shaped dough in a banneton and cover it with plastic wrap or a bowl cover. Place the covered banneton in the fridge and let it rest there for at least 12 hours, no longer than 96 hours, before baking. That’s it!

Why should you cold ferment sourdough?

Cold fermenting sourdough offers a ton of benefits, including more complex flavors, easier digestion, a lighter crumb, a firmer surface for scoring, and a more flexible baking schedule for the baker.

What do you do after cold fermenting sourdough?

After cold-fermenting your sourdough, you can bake it! Preheat your oven to 475°F with a Dutch oven inside. Pull out your banneton and flip the dough onto parchment paper. Dust the top of your dough with rice flour. Score the top of your dough and place it inside your preheated Dutch oven. Bake for 25 minutes. Lower the oven temperature to 425°F, take off the Dutch oven’s lid, and bake for another 20-25 minutes.

When do you cold ferment sourdough?

The cold fermentation is the final step of the sourdough preparation process. During the day, you mix your dough ingredients together (bread flour, water, sourdough starter, and salt), complete several rounds of stretch and folds, and wait for the bulk fermentation fo finish (try the float test to master that timing!). Then, pre-shape, final shape, and place your sourdough in a banneton. Finally, you’ll put your covered banneton in the fridge for the cold fermentation.

Does cold proofing make my dough rise more?

Cold proofing does make your dough rise more, but it shouldn’t become an issue if you bake it before the fourth day. The best way to ensure your dough doesn’t overproof is to limit the cold proofing to 12-72 hours. I find 12-36 hours is ideal.

Conclusion

While you can skip the cold retard in the fridge, I recommend letting it rest there for 12-36 hours. The flavors will develop, it’ll be much better for your digestive system, and you can tailor your daily routine much more easily.

Let me know in the comments how long you prefer to proof sourdough in the fridge!

Related: How Long Does Sourdough Bread Last? + Storing Tips