The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Extending fermentation with less yeast and more time

dantortorici's picture

Extending fermentation with less yeast and more time

I've read somewhere that you can calculate extended rise time with the following:


amount of yeast for original recipe * rise time for original recipe = amount of new yeast * rise time for extended modified recipe

So for grams and minutes it might be something like:

5 * 60 =  new yeast * 120     where a doubling of rise time would use half the yeast at 2.5 gr.


My question concerns which rise time? I imagine it is bulk fermentation but does that mean that after shaping proof time would be same as original?

How about when a starter, biga, poolish, or equivalent is involved? Does that yeast get modified too?




Frequent Flyer's picture
Frequent Flyer

...I don't think it's linear.  I recently reduced yeast in a recipe by 1/3 and saw no real change.  The next day I cut it by half and saw bulk rise times increase from 45 minutes to 60 minutes. 


longhorn's picture

Doubling time for yeast is a function of temperature (hydration, sugar content, salt, acid, and a lot more). At any given temperature the doubling time will be relatively constant for a given yeast.

A fair rule of thumb would be two hours to double at 80F. So if you halve your yeast you need about 2 hours to get back to where you started the other dough and another hour to get to the same point as one hour on the original - so you need to jump from one hour to three hours - two will be underproofed. But that is only an estimate. Reality will likely be different.

dantortorici's picture

Sure enough, it was here at TFL that I read about the formula and was from Norm, an authoritative source as he was a professional baker for many years. Check out the link below.