You haven't been able to compare Grandma's Original with Brer Rabbit Mild, have you? Grandma's must be lighter if 7% is going to be used because from my comparisons, 5% BR Mild is just about dead on from a color standpoint. No worries either way. I don't know if I'll go get some Grandma's or not. I may try 5% BR Mild and then the brown sugar from there.
Also Peter - any thoughts on the "failed" 4-day cold fermentation, in terms of affecting the sweetness? I know it wasn't exactly germane to the exercise at hand, but would be educational to me if you have any insight.
The Brer Rabbit Full Flavor molasses, which is a second boil molasses, was the only Brer Rabbit molasses at my local supermarket. The Brer Rabbit Mild is a first boil molasses. I have been treating the Grandma's Original molasses as a first boil molasses but I learned recently that it is apparently packaged before the first boil. To my way of thinking, that may make the Grandma's Original molasses more of a Fancy grade molasses, which is the lightest of the retail brands of molasses but with the most sugar. You can see how the company that sells the Brer Rabbit and Grandma's molasses compares the various versions at those products at http://www.bgfoods.com/int_faq.asp
. Also, see the Cook's Illustrated comparison test results for different brands of molasses at http://www.cooksillustrated.com/tastetests/overview.asp?docid=32258
In your case with the Brer Rabbit Mild molasses, you won't need as much of that product as the Grandma's Original molasses because it is darker than the Grandma's Original molasses. And it will also have less sugar to contribute to crust sweetness. So, unless you don't care about the final dough and crust color, you may have to increase the amount of the light brown sugar to achieve that elusive crust sweetness.
As I noted recently, it is also possible that there are variations in the color of the dough balls at the various MM stores that are natural and unavoidable consequences of a commissary process that uses a liquid form of molasses. So you, Norma and I may be chasing our tails trying to make our dough balls look like the MM dough balls we saw, and where that benchmark color is in our minds only or through photos or other images that might not be entirely reliable because of different cameras and different lighting. In your case, you would have to make one of your dough balls that you think is of the right color and take it to one of your local MM locations and ask to compare it with one of their dough balls. You could do likewise if you were to be able to find an MM location that will sell you one of their dough balls.
On the matter of your "failed" four-day cold fermented dough, the sugar that contributes to final crust sweetness is called "residual sugar". Residual sugar is that sugar that remains in the dough at the time of baking. The amount of the residual sugar will depend on several factors, including the hydration of the dough, the amount of salt, the amount of yeast, any added sugar and its amount, and the manner and duration of fermentation (e.g., at room temperature or in the refrigerator). All else being equal, a low hydration dough will ferment faster than a lower hydration dough (because of reduced mobility of water and reduced biochemical activity), a dough with a lot of salt will ferment slower than one with a small amount of salt (because of its osmotic effect on yeast), a dough with a lot of yeast will ferment faster than one with a small amount of yeast, and a dough at room temperature will ferment faster than one fermented under refrigeration. If sugar is added to the dough, it can also slow down the fermentation process if it is used in a large enough amount because of its osmotic effect on the yeast. So, if in your case you used a low hydration for your dough, a small amount of yeast, a normal amount of salt, a cold fermentation, and a fairly large amount of added sugar, you should have had a fairly high residual sugar level to contribute to final crust sweetness at the time of baking (and also to crust coloration because of caramelization and the Maillard reactions). If you did not detect a noticeable sweetness, that perhaps means that you did not get enough sugar out of your molasses and the amount of added sugar was too low. In my last experiment, I used 7.5% Grandma's Original molasses and 7% raw cane sugar and the finished crust was overly sweet. That is why I went to 7% Grandma's Original molasses and 4% light brown sugar for my latest experiment. I won't know until I make the pizza whether that is the right combination or not but I was at least satisfied with the color of the dough.
The same factors as discussed above will also apply to an MM dough, whether it is a fresh dough or a frozen one. It is the numbers that will be different, not the principles.