preferment vs cold fermentation: experiment by Adam Ragusea

Ilya,  Thanks,  I watched it and thought it was an interesting experiment, especially where he uses "too much " yeast in the preferments. 

Super interesting, Ilya. Thx!

This is a much more complete yeast version of an experiment I posted about in one of the recent threads on jail-break bread. I took a pain de campagne recipe I have always liked and made it two ways -- one as specified, with an overnight stiff levain followed by bulk fermentation and cold proofing the next day, and one jail-break style, mixing everything together, leaving it on the counter for 12 hours and then refrigerating it for another 12 hours.

The levain version rose a tiny bit better. But the jail-break version tasted a whole lot better.

Rob

Certainly more time => more flavor, but I wondered about the difference between time in a room-temp overnight poolish vs overnight bulk fermentation in the fridge.  I finally found a source that explained that different hydrations and temperatures favor the lactobacilli over the acetobacilli, or vice versa, even in commercially yeasted doughs.  I don't remember the sources but here's a digest from a few different places.  Perhaps Ragusa didn't notice the falvor differences between his poolish and the retarded fermentation.  I probably wouldn't, either. 

Here’s what happens when dough ferments:

• Enzymes (mainly amylase) break down the large chain starches in the flour into sugars

• Malted/sprouted grains and malt additives promote the breakdown of starches

• Yeast (commercial or wild) eat the sugars, pee alcohol, and fart CO₂ (which makes bread rise)

• Bacteria eat the sugars and pee lactic acid (lactobacilli) and acetic acid (acetobacilli); these give the flavor to the bread

• Higher hydration favors lactobacilli (making acetic acid requires oxygen; the water blocks access to air) - use a poolish or a liquid levain (see below)

• Wheat starters favor lactobacilli; rye produces more acetobacilli

These are the ways to get more tasty organic acids into bread dough:

• Ferment some of the flour in advance

• Use a sourdough culture; the first step for making dough is to add flour and water to some of the starter to make a levain 8-16 hours before mixing the dough

• A rye starter needs 12-16 hrs at room temp (75℉ in the proofer for my warm weather San Diego rye starter) to ferment a levain

• For small home-sized batches, increasing the percentage of mature culture in the sourdough build (by 25 to 50% or so compared with the percentage in the book for large commercial batches) may be a good way to improve the ripening of the final dough, especially if there is no commercial yeast in the formula - “Bread”  3rd edition 

• Use a preferment (pre-ferment) to get commercial yeast going on some of the flour.  Poolish (high hydration), biga (stiff), or pate fermentee (dough saved from a previous batch).

• Slow down the yeast relative to the bacteria by using retarded fernentation, ie, bulk fermenting the dough in the refrigerator overnight; may not work for sourdough

• Poolish vs long retarded bulk fermentation:

• Different flavors develop at different temperatures - retarded fermentation can produce deeper flavors due to more organic acids

• Poolish creates acid which promotes longer keeping.  

• Poolish liquidity promotes protease enzymes which eat gluten making the dough more extensible

• Poolish yeast % of flour in poolish; less yeast on warm days, more yeast on cool days

• 8 hr  0.23% - 0.33%  ⅛’s tsp per 100g flour .6 - .85

• 12 hr 0.1% - 0.2%    ⅛’s tsp per 100g flour  .25 - .5

• 16 hr 0.03% - 0.08%    ⅛’s tsp per 100g flour .1 - .2 

• Fully fermented when covered with bubbles, froth

• Another set of poolish yeast %’s, from an Italian web site,  The differences may be related to lower protein Italian flour

• - 1-2 hours 2.5% of yeast on the weight of the flour; 

• - 4-5 hours 1.5% of yeast on the weight of the flour; 

• - 6-7 hours 1% of yeast on the weight of the flour; 

• - 8-9 hours 0.5% of yeast on the weight of the flour; 

• - 10-12 hours 0.3% of yeast on the weight of the flour; 

• - 13-14 hours 0.2% of yeast on the weight of the flour; 

• - 15-16 hours 0.1% of yeast on the weight of the flour.

• More preferment => faster bulk fermentation and proofing

• Signs that a preferment/sourdough is ready include these:

• Dome

• Lots of little bubbles/holes

The History section of https://en.wikipedia.org/wiki/Pre-ferment says that the idea of "poolish" coming from Polish bakers in France is BS:

The common, but undocumented, origin given for the term poolish is that it was first used by Polish bakers around 1840, hence its name, and as a method was brought to France in the beginning of the 1920s. "Poolish" however is an old English version of "Polish", whereas the term seems to be most used in France (where "polonais" is the word for "Polish"). Some nineteenth-century sources use the homophone "pouliche", a French word that typically means a filly.[15] With either spelling, the term only appears in French sources towards the last part of the nineteenth century. There is not currently any credible explanation for the origin of the term.