Baking is my new hobby and I am experimenting a lot. There is an interesting observation and a guess, I'd like to hear some opinions from more experienced bakers.

I have a number of failures with the recipes where dough required to be fermented in the fridge, e.g. ciabatta bread. With a number of trials I figured out that the less time the dough spend in the fridge the better result I see. And just today I realized that the fridge I have is with O3 (ozone) generator.

So my guess is that ozone kills the bacteria required for the fermentation. This would also explain the fact that the less time the dough spent in the fridge the better result I see.

I didn't try yet to ferment the dough with ozone generator off. But will do it this week.

What do you think about this? I wonder whether it is all makes sense or pure silliness and I should look for an issue elsewhere.

  • 5
    Why do you say your fridge generates ozone? Is this a special feature? Could you point us to its specifications?
    – Chris H
    Commented Apr 20, 2020 at 19:49
  • 1
    Sure, it is not the manual from exactly my fridge, but very similar from the same vendor: docs.hotpoint.eu/_doc/F088570_IFU.pdf. See page #3, look for Active Oxygen.
    – Anton
    Commented Apr 20, 2020 at 20:11
  • Well I've never come across that before. I'm not sure of the benefit, as the few things that spoil in my fridge are (like most things in there) sealed. I suppose if fruit and veg are consumed very slowly it may help, but proving dough (or indeed storing a starter) in the fridge has to be done in an unsealed container so the ozone could be a problem
    – Chris H
    Commented Apr 20, 2020 at 22:01
  • TIL some fridge have ozone generator.
    – Max
    Commented Apr 20, 2020 at 22:04
  • I will update this question with an answer as soon as I re-do the experiments and be sure ozone is affecting or not affecting the result. :-)
    – Anton
    Commented Apr 21, 2020 at 11:41

2 Answers 2


I was experimenting for almost a month and now I can confirm that enabled Ozone(Active Oxygen) does indeed impact, kills really, on the dough and bacteria during cold fermentation. The results I have with Ozone off are fantastic. And out of curiosity I also did cold fermentation with Ozone enabled. I kept the dough for 14 hours and got terrible bread.

  • It makes sense that it would have an affect -- ozone is used to disinfect water (it just doesn't have any long-term preventative effects like chlorine, as it doesn't stay in the water). Oh ... and ozone can cause some materials to degrade (aluminum, anything with a natural rubber seal), so you might need to be careful about what containers you use: ozonesolutions.com/knowledge-center/…
    – Joe
    Commented May 15, 2020 at 15:10

What are you using as fermentation agent? Yeast or sourdough? Sourdough will proof much slower, and possibly not noticeable at all in the fridge.

However, I've been baking bread using retardation overnight in the fridge for years. And with great success.

Personally I've never heard of a fridge that can create ozone


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