Warmer weather can be one of the trickiest times to bake sourdough especially if you’re new to it. A dough that behaves perfectly in winter can suddenly feel sticky, over-proofed, or like it’s moving far too fast in summer.
Add humidity into the mix and things can feel even more unpredictable. The good news is that with a few simple adjustments, you can stay in control of your dough and continue baking beautiful sourdough all year round.
Why Warm Weather Changes Your Dough
Sourdough is a living dough, and both heat and humidity directly affect how it behaves. As temperatures rise, the wild yeast and bacteria in your starter become more active, which speeds up fermentation. This means your dough will rise faster and move through bulk fermentation more quickly than it does in cooler months.
Humidity adds another layer. Moist air prevents flour from absorbing water in the same way, which can leave dough feeling softer, stickier, and harder to handle. Understanding how these elements work together is the first step to adjusting your process.
Shorten Your Bulk Fermentation
In warmer weather, bulk fermentation is usually much shorter than the timings written in most recipes. Dough that once took six to eight hours may now be ready in as little as three to four.
Rather than watching the clock, it’s important to watch the dough. During bulk fermentation, your dough should rise by around 30–50 per cent, look smooth and slightly domed on top, and feel lighter and airy when handled. If you push bulk fermentation too far in warm conditions, the dough can quickly become over-proofed and lose strength.
Adjust Your Water Temperature
One of the simplest ways to slow fermentation is to use cooler water when mixing your dough. In summer, there’s rarely a need for warm water, as your kitchen environment is already providing plenty of heat.
Using cool or cold water helps regulate dough temperature from the very beginning, giving you more control and preventing the dough from fermenting too quickly. This small change can make a big difference, particularly on very hot days.
How Humidity Affects Dough
Humidity plays a major role in how your sourdough feels and behaves. On humid days, flour naturally absorbs moisture from the air, which means your dough may feel wetter and stickier than usual, even if you’ve followed the recipe exactly.
In these conditions, it’s often helpful to hold back a small amount of water when mixing and only add it if the dough feels too stiff. You may also notice that your dough strengthens more slowly during stretch and folds, so be guided by how it feels rather than how it looks at a specific time.
Consider Using Less Starter
If your dough seems to be fermenting too fast in warm or humid weather, reducing the amount of starter can help slow things down. Less starter means fewer active yeast cells at the beginning of fermentation, giving you a longer, more manageable bulk phase.
This adjustment is especially useful during heatwaves or when your kitchen stays warm well into the evening.
Use the Fridge to Your Advantage
Your fridge is one of the most valuable tools for baking sourdough in warm weather. If your dough is progressing faster than expected, a short rest in the fridge during bulk fermentation can help slow things down.
Cold proofing shaped dough in the fridge overnight is also particularly helpful in summer. Not only does it improve flavour and structure, but it also makes the dough easier to score and allows you to fit baking around your schedule.
Be Gentle With Stretch and Folds
In warmer conditions, gluten develops more quickly, which means you may not need as many stretch and folds as you do in cooler weather. Overworking the dough can lead to a sticky, slack texture that’s difficult to shape.
Once your dough feels smooth, elastic, and holds its shape well, it’s usually best to stop and let fermentation do the rest of the work.
Watch the Dough, Not the Recipe
The most important thing to remember when baking sourdough in warmer or more humid weather is to stay flexible. Recipes provide a guide, but your dough will always respond to its environment.
Pay attention to how your dough looks, feels, and moves, and adjust as needed. With practice, you’ll start to recognise the signs of perfectly fermented dough, no matter the season.
Final Thoughts
Baking sourdough in warm, humid weather is all about small adjustments and learning to read your dough. By shortening bulk fermentation, managing hydration, and making smart use of the fridge, you can stay in control and keep baking confidently through summer.
Happy baking 🤍