Ed,
In my experience making all kinds of doughs, including long, room-temperature fermented doughs and cold fermented doughs, my results have mirrored the effects described in the material you quoted. With particular respect to room-temperature fermented doughs, I found that the fermentation temperature was an extremely powerful force, especially in the summer where room temperatures where I live in Texas can exceed 80 degrees F for long stretches. Both yeast and enzymes are more active, and also more efficient, at warmer temperatures than at cooler temperatures, so you can expect more fermentation activity and more enzyme activity than you will get in a cold fermented dough over normal fermentation periods. In addition to the accelerated fermentation because of the high room temperatures, there are also protease enzymes in the flour that attack the gluten and soften it and cause the water bond to be broken, resulting in a weakened, slack and wet dough. In my experiments, it did not much matter whether I used oil in the dough or not. In many instances, the amount of oil was over 7% of the formula flour. In my case, to slow down the fermentation process, I found it necessary to reduce the amount of yeast to miniscule quantities--less than 1/10th of what you used in the two dough formulations you posted. Had I not done so, I would have ended up with a weak structured dough with poor gas retention.
In your case, with only 1% oil, I am not sure how much effect it would have on your dough in terms of its strength. Since you are using KASL, which is a high protein flour, that flour can utilize a fair amount of oil, perhaps considerably in excess of 1%. So, its possible that 1% oil will have minimal effect. As you noted, the oil will have modest effect on slowing down staling and drying of the crust because of its effect to retain some of the moisture in the dough, by preventing the moisture in the dough from evaporating as much or as quickly during baking. Sugar in the dough can have a similar effect. A crust made using a dough without oil or sugar will go stale rather quickly, much as a freshly made French baguette has to be eaten quickly while the crumb is still soft.
As for your question about the effects of salt and sugar on a 24-hour cold fermented dough as opposed to a 48-hour cold fermented dough, the answer will depend on the amounts of each ingredient. Salt is considered to be a regulator of the fermentation process, with high levels slowing down the fermentation process and low levels increasing it. Of course, there are limits to how much salt you can use in a dough, not only because of the effects of salt in regulating the fermentation process but also because of taste and tolerance factors. The recommended range of salt in yeasted doughs is around 1.5-2%. Sugar can also affect dough performance by inhibiting yeast activity if it is used in excess. As noted in the following excerpt from
http://home.earthlink.net/~ggda/The_Artisan_Yeast_Treatise_Section_One.htm, both salt and sugar can exert osmotic pressure on yeast.
Osmotic Pressure
The osmotic properties of a yeast cell are due to selective permeability of the cell wall with regard to solutions. This selectivity plays an important role in controlling the movement of nutrients into a cell. Nutrients are present in a medium in the form of ions, sugar, and amino acids. The permeability of the cell wall also permits the release of alcohol and carbon dioxide from the cell during fermentation.
High concentrations of sugars, inorganic salts, and other solubles inhibit yeast fermentation as a result of effects produced by high osmotic pressures. Basically, all fermentable sugars begin to exert an inhibiting effect on yeast when their concentration exceeds about 5% in the dough, with the degree of inhibition becoming progressively greater as the concentration of the sugar rises. This inhibitory effect is more pronounced with such sugars as sucrose, glucose and fructose than with maltose. The last sugar is a disaccharide that persists as such in the fermenting medium, and therefore exerts a lower osmotic pressure than the monosaccharides and the readily hydrolyzed sucrose, The sensitivity of yeast to osmotic pressure varies with different yeast strains, with some being better suited than others for fermenting sweet doughs with their high sugar contents.
Salt exerts a similar osmotic effect, except that some fermentation inhibition appears to set in at concentrations below the normal 2.0% level. A decrease in gas production occurred over a four (4) hour period when the concentration of sodium chloride was increased from 1.5 to 2.5% in a straight dough. One percent (1%) salt, based on flour, exerts an osmotic effect that is equivalent to that of 6% glucose.
Salt in concentrations over 1.5% exerts an inhibitory effect on yeast activity, either by its osmotic pressure or by a specific chemical effect. For this reason, Salt is generally withheld from the sponge in the sponge-and-dough process. Interestingly, it has been shown that at lower levels, rather than being detrimental, salt actually exerts a favorable influence on yeast fermentation, A series of studies have shown that the use of 0.5 to 1.0% salt in the sponge of a sponge-and-dough process resulted in reductions in the fermentation time, while at the same time producing a better quality bread than was obtained with a sponge containing 0.15% or no salt.In my opinion, rather than using salt and sugar as vehicles for altering dough performance, it is perhaps better to adjust the amount of yeast used, together with the hydration and fermentation temperature, in order to have a desired end effect on the finished product. Water temperature can also be used to affect the fermentation process. As an example, if you want to extend the window of usability of a 24-hour cold fermented dough to 48 hours, you can do this by reducing the amount of yeast and/or using cooler water. Reducing the hydration can have a similar effect, however the hydration can't be lowered too much without affecting the handling qualities of the dough. I frequently do all of the above, that is, use less yeast, cooler water, and a slightly lower hydration. I don't use salt or sugar for fermentation control. If I were in Naples making authentic Neapolitan room-temperature fermented doughs, I would use salt quantity for fermentation control purposes. But not for cold fermented doughs. Ultimately, you want to have balance of all the ingredients in the dough formulation and proper dough preparation and management to achieve acceptable gas production and retention. It often takes a fair amount of experimentation to achieve these results.
Peter
