The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Max Fermentation Temperature

jombay's picture

Max Fermentation Temperature

Hey all,

I built up 30g of my starter to 250g, then left it my electric oven with the light on overnight. Checked the temperature with my instant baking thermometre in the morning and it was around 95F. Is this alright or too hot?


Matt's picture

You tell us.

How does the finished product taste?

IMHO, the more sour, the better.

If I'm going to take the pains to make a sourdough bread, it should be really strong.

Otherwise; go to the supermarket and buy average sourdough bread.


LindyD's picture

Presuming you have a higher hydration culture, the temperature range is 70-95F, so you're in the ballpark, albeit in the top row.   The warm, wet environment will produce bacteria with a less sour taste than a drier culture held in a cooler spot.

Was it able to raise your bread or did  you have to refresh it before using it?

Andrew S's picture
Andrew S

You should have just scraped through if all things were going at full speed in a healthy starter.  You could give it a little feed and look for signs of life.  If it has survived,  it should be lively quite quickly.

Your baking session may be delayed but you have the chance to preserve our most holy of holies,  A lively happy starter that makes YOUR bread the best there is.


Go forth and bake.


Andrew S


ananda's picture


Generally, yeast is happiest at 37*C [98F]; which is the same as our bodies!

However, a ferment at this high temperature will tend to develop some unpleasant tastes and odours.

My preferred maximum temperature for early fermentation is 30*c [86F]

But you won't kill yeast until it is confronted by temperatures in excess of 53*C [127F]

Sorry, the fahrenheit is approx as I only really work Celsius; hope this helps


hutchndi's picture

Your little buddies had a huge party last night. The danger is not so much that you fried them, the danger would have come from leaving them in there longer while they partied themselves to death in the lovely weather in there. The closer they inch towards the limits of their temperature range, the more of a feeding frenzy is going on, nutrients being depleted like no tomorrow. So what was the condition of the starter upon retieving it from the oven? Bubbly and warm? Runny and spent? Covered in hoochy koochy?

This aint no disco, no CBGB, this aint no foolin around.....

jombay's picture

Thanks for the replies everyone. Yeh he survived and raised some nice tasting loaves. They were devoured before I could take pics.