Sourdough in Summer: How to Bake When Your Kitchen Is 85°F

Summer kitchens are brutal on sourdough. A dough that takes 6 hours of bulk in February can be ready in 3 hours in July. Here's how to adapt your routine to hot weather.

The fundamental problem

Yeast roughly doubles its activity for every 10°F rise in dough temperature. A 70°F dough that takes 6 hours of bulk takes 3 hours at 80°F and 1.5 hours at 90°F.

In a hot kitchen, your traditional sourdough timing is wrong. You'll consistently overproof and get flat, sticky bread.

Strategies for hot weather

1. Use cold water at mix

The single biggest lever. Use ice-cold water (or even add a few ice cubes to the water).

A dough that mixes at 70°F instead of 80°F gives you 3–4 extra hours.

2. Bulk in the fridge

Skip room-temperature bulk fermentation entirely. Mix, do 2 quick folds, refrigerate immediately. Let bulk happen in the fridge over 18–24 hours.

This is the most reliable hot-weather method.

3. Reduce starter percentage

A standard 20% starter is too much in summer. Drop to 12–15% to slow things down.

4. Reduce salt slightly (not much)

Salt slows fermentation. Use 2.2% salt instead of 1.8% to add a small braking force.

5. Bake early in the day

Mix and shape during the cool early morning. Bake before the kitchen heats up. By noon, you're done.

6. Use a wine fridge or cooler

A wine fridge set to 68°F gives you stable bulk fermentation regardless of kitchen temperature.

A regular cooler with frozen ice packs maintained at 65–70°F works similarly.

A summer schedule

Day 1, evening

• 9 PM: Mix dough with cold water, autolyse 20 minutes
• 9:20 PM: Add cold starter and salt, mix
• 9:30 PM: Quick fold
• 9:35 PM: Cover and refrigerate

Day 2, all day

• Dough sits in the fridge

Day 3, morning (cool part of day)

• 6 AM: Pull from fridge
• 6:15 AM: Pre-shape, rest 15 minutes
• 6:30 AM: Final shape, return to fridge
• 7 AM: Preheat Dutch oven (open windows)
• 7:45 AM: Bake
• 9 AM: Done before kitchen overheats

Cooling shortcuts

If you've already mixed warm and your dough is fermenting too fast:

• Move to the coldest spot in your home
• Surround the bowl with frozen water bottles
• Move to the fridge for the rest of bulk
• Cut starter percentage for next bake

A lot of summer overproofing happens because bakers don't adapt mid-bake.

What to avoid in summer

Long room-temperature autolyses — the flour starts fermenting on its own.

Long counter-side bulks — you'll lose track of time and overproof.

Big starter percentages — speeds fermentation more than your timeline can handle.

Hot-water mixes — pushes initial dough temp too high.

Monitoring dough temperature

Get an instant-read thermometer. Check dough temp:

• At mix: aim for 70–72°F
• At end of bulk: should be 75–78°F
• If it's hotter, fermentation is faster than you think

Air conditioning helps

If you have AC, a 72°F kitchen makes summer baking like fall baking. The cost of running AC during a baking day is about $1–2. Sometimes worth it.

If you don't have AC, embrace the cold-bulk routine and bake before the day heats up.

Whole grain considerations

Whole wheat and rye flours ferment faster than white flour. In summer, reduce the percentage:

• Year-round recipe: 25% whole wheat
• Summer adaptation: 15% whole wheat

This gives you more headroom on timing.

Refreshing your starter daily

Heat makes starters more active and acidic. In summer:

• Feed your starter daily, even when not baking
• Use a higher feeding ratio (1:5:5 instead of 1:1:1)
• Refrigerate between feeds
• Check for hooch more often

A starter that gets too acidic in summer produces sour, sluggish bread.

Pizza and flatbreads in summer

Some breads work better in summer:

• Pizza dough — fast fermentation matches summer's pace
• Focaccia — pan-baked, doesn't need long cold proofs
• Pita — high-heat bake doesn't add much kitchen heat
• Tortillas — stovetop, oven stays off

Switch your summer baking toward these and your kitchen stays cooler.

Outdoor options

Summer is grill-bread season:

• Pizza on the grill (better than indoor pizza in summer)
• Flatbreads on a hot grill grate
• Naan over coals
• Bagels boiled outdoors

Keep the heat outside.

The mindset shift

Summer sourdough requires faster, smaller bakes. Don't try to do your winter routine in July.

Embrace:

• Smaller loaves (faster bake, less heat in kitchen)
• More frequent bakes (each one is shorter)
• Different breads (focaccia, pizza, pita instead of country loaves)

When to take a sourdough break

It's ok to scale back sourdough in deep summer:

• Bake once a week instead of twice
• Refrigerate your starter for storage
• Focus on no-bake meals
• Resume in fall when temperatures drop

A starter survives a month of fridge storage easily. Don't burn yourself out trying to maintain a winter routine in summer.

Coming back from summer

When fall arrives:

• Pull starter from fridge
• Feed twice daily for 3 days to wake it up
• Resume normal bakes
• Adjust timing back to longer bulks

Your starter will probably be very active for the first few bakes — feeding has been less frequent. Use that energy for great oven spring.