MWTC,
Thank you for posting your poolish-based dough recipe. I have been studying different preferments for some time and see them as an effective way of adding flavor and other positive attributes to a pizza crust. As you know from my comments elsewhere on the forum, I am very interested in how you have been able to achieve doughs with a lifespan of several days—10 days with your latest dough using the poolish-based dough formulation. To study your formulation, with the hope of divining how you achieved a dough lifespan of 10 days, I converted your dough recipe to the following format:
Total Formula:
Flour (100%):
Water (60%):
Salt (0.675%):
ADY (0.225%):
Oil (1.25%):
Sugar (4.5%):
Total (166.65%):
|
800 g | 28.22 oz | 1.76 lbs
480 g | 16.93 oz | 1.06 lbs
5.4 g | 0.19 oz | 0.01 lbs | 0.97 tsp | 0.32 tbsp
1.8 g | 0.06 oz | 0 lbs | 0.48 tsp | 0.16 tbsp
10 g | 0.35 oz | 0.02 lbs | 2.22 tsp | 0.74 tbsp
36 g | 1.27 oz | 0.08 lbs | 9.03 tsp | 3.01 tbsp
1333.2 g | 47.03 oz | 2.94 lbs | TF = N/A
|
Looking at the above data prompts me to ask you about the yeast quantity you used. You indicated that you used ¾ teaspoon of ADY, whereas my numbers suggest something less than ½ teaspoon. To be on the safe side, I weighed 1.8 grams of ADY (SAF brand) on my MyWeigh 300-Z scale and got a bit less than ½ teaspoon, not ¾ teaspoon. The difference ordinarily wouldn’t be terribly significant but since you added the sugar to the poolish along with the yeast the difference may be an important consideration. More specifically, when you added the sugar and yeast to the flour and water to form the poolish, the sugar had a baker’s percent of 18% (36/200 = 18%). As noted in this King Arthur article,
http://www.kingarthurflour.com/professional/yeast.html, once you get above 9% sugar there is a reduction in the rate of fermentation because of osmotic pressure as sugar, which is a hygroscopic substance, and the yeast compete for the available water (along with the flour).
I have also read that there is an optimum ratio of sugar to yeast of 3:1, at
http://www.classofoods.com/page1_4.html (see the penultimate paragraph under sugar, at 1.4.2). In your case, the sugar/yeast ratio in the poolish and in the total formula is 20, assuming 36 grams of sugar and 1.8 grams of yeast. I can’t vouch for the validity of the 3:1 ratio since I have not seen it anywhere else but the referenced article. So, the lack of confirmation is an issue. However, I do note that one of our members, DINKS, a baker by training, periodically rails against dough recipes in which the quantity of sugar is much greater than the amount of yeast (see, for example, the middle of Reply 5 at
http://www.pizzamaking.com/forum/index.php/topic,3480.msg29500.html#msg29500).
It is quite possible, I suppose, that the high levels of sugar may have suppressed the yeast and, hence, the rate of fermentation such that the lifespan of the dough was extended beyond what might have been considered normal. I originally thought that the use of the cold water as part of the final mix may have been a factor, but since you indicated that the finished dough temperature was 70 degrees F, I ruled that out as a factor. And, if your refrigerator was operating at a normal temperature, I didn’t see that as a factor either.
An interesting experiment would be to repeat the recipe but leaving the sugar out of the poolish. Normally, by definition, a poolish includes only flour and water, in equal amounts by weight (i.e., 100% hydration), and all or part of the total formula yeast. You might also revisit the amount of yeast you have been using just to have the right numbers to analyse your situation.
Peter
