Do I need to cold ferment my dough?
You’ve probably seen it everywhere—“Sourdough needs to be cold fermented in order to get the benefits of digestibility and nutrition.” Is this true, though? Spoiler alert: it’s not!
Let’s break this down. The term "cold fermentation" is actually a misnomer. It’s often used to refer to a refrigeration step known in bakery jargon as a cold retard. The word “retard” here comes from the French retarder, meaning "to delay"—essentially, it’s a technique used by bakers to hold the dough for longer periods in a state of readiness before baking. This step is more about time management than anything else. Does it impact flavor and texture? Sure. But whether it’s positive or negative really depends on who you ask.
In fact, the cold retard became popular because it allowed bakers to take a break and get some sleep instead of working through the night to prepare fresh bread.
Fermentation Dynamics
When it comes to sourdough, both yeast and bacterial activity increase as the temperature does. For every 10°C increase, activity essentially doubles. Warmer temperatures also increase enzymatic activity, such as the action of alpha-amylase, which breaks down starches into fermentable sugars, and protease, which helps shorten gluten strands.
Here’s a quick rundown of the ideal fermentation temperatures:
- Lactic Acid Bacteria (LAB) perform best at 32-33°C (90-91°F).
- Wild yeast, like Saccharomyces cerevisiae, thrives around 27°C (80°F).
These microbes work best between 20-28°C (68-82°F), which is the sweet spot for sourdough fermentation. This makes it clear: it’s factually inaccurate to say that cold temperatures are necessary for a well-fermented dough.
Cold Fermentation Pitfalls
One of the key issues with cold fermentation is that once dough cools down to fridge temperature, fermentation essentially grinds to a halt. If your dough was under-fermented before you put it in the fridge, it could stay under-fermented for days without significant improvement. Moreover, the time it takes for dough to cool in the fridge and reach its retard stage can be unpredictable, depending on factors like fridge temperature, the volume of dough, and even how often you open the door.
In short, while cold fermentation can provide some practical benefits, it’s not the magic trick it’s often made out to be.
Putting Theory into Practice
Trust me when I say that I see a lot of so-called "long fermented" dough that is actually under-fermented. I’d argue that a good 85-90% of the sourdough bread I see online is under-fermented to some degree. Meanwhile, I can take a dough from bowl to bake in just 6-8 hours, using a higher percentage of pre-fermented flour and bulk fermenting it at warmer temperatures. The result? A fully fermented, delicious loaf of bread.
The key here is learning how to read fermentation cues, which is much easier when you’re not juggling multiple temperature gradients. Plus, let’s not forget that the time spent pre-fermenting flour is part of the long-fermentation process, even if it doesn’t involve cold temperatures.
The Bottom Line
A well-fermented dough is a well-fermented dough, regardless of the temperature it was fermented at. The true benefits of sourdough come from the metabolic activity of the yeast and bacteria. That's what makes sourdough both nutritious and digestible. Cold temperatures aren't the secret; proper fermentation is.
And while you can incorporate a cold retard into your process—whether for flavor, time management, or convenience—don’t fall for the assumption that colder and longer always equals better. As long as you get the fermentation right, you’re on the path to making great bread.
Want more info on the science of sourdough? Check out the full study by Michael Gänzle et al. here.
Happy baking!
