What You’ll Learn
- Why Dutch ovens scorch bases.
- How rack position affects heat.
- How to shield the loaf.
- When to reduce temperature.
- How parchment differs from insulation.
Quick Answer
If your sourdough burns underneath, reduce direct bottom heat. Move the pot higher, place a baking tray underneath, lower the finishing temperature or use insulation between the loaf and the strongest heat source.
This lesson is part of our Troubleshooting section: “Fix the most common sourdough problems.”
Bottom Heat
Many ovens direct intense heat from below.
Dutch Oven Heat
Heavy cast iron stores and transfers a lot of energy to the base.
Move the Rack
One shelf higher can make a major difference.
Use a Heat Shield
An empty baking tray on the shelf below can reduce direct radiation.
Lower the Finishing Temperature
Keep strong initial heat for oven spring, then reduce later.
Parchment
Parchment prevents sticking but provides little thermal insulation.
From Our Workshop
A perfect loaf with a black base is usually telling you more about the oven than the recipe.
Bake Slower Tip
Change rack position before changing your entire bake temperature.
Common Mistake
Do not add extra flour under the loaf expecting it to protect against strong radiant heat.
Today You Learned
- Burnt bases usually come from excessive bottom heat.
- Cast iron intensifies heat transfer.
- Rack position can fix it.
- A tray below can shield the loaf.
- Parchment is not insulation.
Frequently Asked Questions
Will cornmeal stop burning?
Not reliably.
Can I use two sheets of parchment?
It may help slightly but does not solve severe heat.
Should I reduce the oven temperature?
Possibly after the initial bake stage.
Can a pizza stone make it worse?
Yes if it intensifies bottom heat.
Does silicone help?
A suitable bread sling may slightly buffer contact.
Tools Mentioned in This Guide
These products are directly related to the troubleshooting steps covered in this lesson.
Make the Next Bake Easier
Protect the base from excessive heat rather than underbaking the whole loaf.
Continue Learning
Next lesson: Why Does My Sourdough Have No Oven Spring?
Troubleshoot one variable at a time
Diagnose from the whole loaf, not one symptom. Compare dough strength, fermentation, proofing, scoring and bake together. Changing several stages at once can hide the real cause and make the next result harder to interpret.