Yeast vs. time question for the "baking is a precise science" folks
So, after about 1.5 years of baking bread, I've internalized what seems like fundamental truth: if you use more yeast, then you must develop the dough more and keep fermentation time shorter. And vice versa. Now, I'm trying to map that to actual mixing times and %age yeast. Mixing time is hard to define, and one man's improved mix is another man's short mix, etc. So time+temp seems the way to go to specify this. Does this look reasonable to the experienced folks:
For a dough with 10%WW/Rye, and 90% APF, Hydration of 69-72%, and Dough Temp of 75 F:
- If you want to bulk-ferment 2.45-3.00 hours (short mix) use 0.3% instant yeast
- If you want to bulk-ferment 2.00-2.15 hours (improved mix) use 0.6% instant yeast
- If you want to bulk-ferment 1.00-1.15 hours (intensive mix) use 1.0% instant yeast
and keep the proofing times approximately the same (poke test to be the final arbiter).
(I don't know whether this is reductionist thinking, but seems useful to have some such guidance in my head if it's accurate).
I think you've got an interesting idea for experimentation. Your times will change with autolyse and salt levels, so you'll want to keep those constant. Another way to look at it is to vary the amount of starter in a sourdough, but that just introduces more variables.
Dan DiMuzio has a table very similar to yours in 'Bread Baking' (page 158), based on a lean dough leavened with instant yeast and fermented at 77F:
0.3% 3-4 hours
0.4-0.5% 1 1/2 hrs
0.7% 1 hour
1% 30-45 minutes
I found two similar tables in translations of two Italian baking reference, not for the bread itself but for preparation of a biga and a sponge. Note the biga veloce uses 5% yeast! (probably fresh) (recalculated for baker's percentages, since the biga uses water as 100%). You could hope that all the formulations would result in the same level of activity at the end of the starter build, so the ratios should hold for the final mix as well.
http://home.earthlink.net/~ggda/Direct_Sponge_and_Biga.htm
La biga veloce (quick biga): 1 part water, 8-10% yeast, and 1.8 parts flour relative to the weight of the water. Shape the dough into a ring and soak it in lukewarm water for 20-30 minutes. Turn the ring upside-down for approximately 15 minutes. When it floats, it is ready. This is an ideal biga for a rich dough.
La pouliche (poolish): 1 part water, 5% yeast, and 1 part flour relative to the weight of the water. The ambient temperature should be about 77 F ( 25 C). The biga matures in 2 hours. The degree of maturity is judged by the intensity of the bubbles that are formed on the surface. This biga is ideal for products that are characteriazed by a thin, crisp crust, elastic crumb and good cell structure.
La biga corta (short biga): 1 part water, 3-5% yeast, and 1.8-1.9 parts flour relative to the weight of the water The duration of the fermentation is approximately 3 hours at an ambient temperature of about 77 F (25 C).
La biga lunga (long biga): 1 part water, 1-1,2% yeast, and 1.9-2.1 parts flour relative to the weight of the water The duration of the fermentation is from 8 to 14 hours. Depending upon the ambient temperature, the fermentation can last for 18 hours at 42.8 F (6 C).
The poolish formulation is in baker's percentages (flour is 100%)
2.5% of yeast for 2 hours of fermentation at ambient temperature
1.5% of yeast for 3 hours
0.5% of yeast for 8 hours
0.1% of yeast for 12-16 hours
Thank you! I have DiMuzio's book, but I omitted to read the "how to create your own" chapter. This is definitely going to be my weekend read. Thanks again!