Question about adjusting yeast % to compensate for hydration.

[I Have Feet]

I'm trying to understand how to adjust the amount of yeast in a dough to compensate for changes in hydration, assuming the same fermentation schedule is desired.

Let's say you have two 500g doughs, one at 65% and one at 75%. Both contain 2% salt and 1% yeast. (Formula chosen purely for ease of illustration, not necessarily meant to represent an actual recipe.)

The 75% dough would contain (rounded to nearest 0.1g):

- 280.9g flour
- 210.7g water
- 5.6g salt
- 2.8g yeast

The 65% dough would contain:

- 297.6g flour
- 193.5g water
- 6.0g salt
- 3.0g yeast

For the same dough mass, the 75% dough contains less flour and therefore less yeast when measured using baker's percentages. Would this reduction in yeast be sufficient to compensate for the higher hydration and produce similar fermentation times or are further adjustments necessary?

I hope I explained that clearly.

Cheers,

Brendan

[The Dough Doctor]

Brendan;
No changes to the yeast level are needed when adjusting the dough absorption up or down within reason. Even though the total dough weight will change, the amount of water present, or the change in water content will have minimal impact upon the yeast fermentation properties. This does not mean that you will not see a difference between doughs with differing absorption, it just means that the difference you see will be the result of a softer, more hydrated dough, which will probably expand more easily, or exhibit more/different flow than a lower absorption dough, rather than the effects of fermentation. Keeping this in mind, when we make a very soft dough with a high absorption, it is common to reduce the yeast level to some extent, not because of the difference in fermentation rate, but because the softer dough ball as well as shaped dough may exhibit excessive flow properties and flatten out too much with a higher yeast level.
Tom Lehmann/The Dough Doctor

[I Have Feet]

Thanks so much for the reply. That explanation makes perfect sense.