First of all, I think you all mean to say "diastatic" and "nondiastatic" rather than "diastolic" or "nondiastolic". Unless, of course, you are trying to elevate each other's blood pressure
I think it is important to distinguish between a dough made by the direct method as opposed to one made from an indirect method. For a dough made using the direct method, and assuming that the flour is malted, I would have no real concerns about the residual sugar levels after a day or a few days of cold fermentation. Beyond that, I could use sugar in many of its forms, including nondiastatic barley malt syrup. In such a case, I might lean to a dry form of the barley malt because it might be easier for Norma to work with and use in the low temperature environment of the market (sometimes in the mid 40 degrees F) where she would prepare the dough. Also, I have discovered that the liquid barley malt can darken the color of the crumb as well as the outer crust. And it doesn't take a lot of barley malt syrup to produce that darker crumb color. For example, a few years ago, I made a clone of a Sbarro's NY style pizza using only 2.2% barley malt syrup. Yet, I could see the effects of the barley malt syrup on the color of the crumb. You can see what I mean from Reply 56 at http://www.pizzamaking.com/forum/index.php/topic,2061.msg40413.html#msg40413
. I experienced the same crumb darkening when I made JerryMac's NY style dough formulation using barley malt syrup. In that case, the barley malt syrup was over 5%, so its effect on crumb coloration was more in evidence. This said, I do not have any problem with anyone using any form of sugar so long as it gets the job done. If Norma and her customers like a darker crumb, then that can be achieved by using barley malt syrup.
My concern with sugar and residual sugar levels is with respect to doughs made using the indirect method, as by using a preferment. Among the different forms of preferment, my concern is greater for a poolish or sponge than say, a stiffer preferment such as a biga or old dough. Liquidy preferments like poolish can be very hard on sugar and deplete it fairly quickly, and especially if the amount of flour devoted to the poolish is a large percent of the total flour. The use of diastatic malt is to make more enzymes available to extract more natural sugars from the damaged starch. The diastatic malt is typically added as part of the final mix. Didier Rosada discusses this issue at http://web.archive.org/web/20050829015510/www.cafemeetingplace.com/archives/food4_dec2004.htm
, with particular reference to the following:When flour and water get incorporated together, enzyme activity starts. Some enzymes generate sugar degradation (amylase), while others provoke protein degradation (protease).
During the pre-fermentation time, the yeast uses up a lot of the flourís sugar, especially during long fermentation time at room temperature. When this portion of flour is added back to the final dough, the overall quantity of fermentiscibles sugar is lower than what is usually available for the yeast in a straight dough method. As a result of the lower availability of sugar, it is difficult to obtain satisfactory coloration of the crust. This defect is sometimes noticeable when a high percentage of overnight poolish or sponge is used in the final dough or when the enzyme activity of the flour is on the low side. To troubleshoot this problem, 0.5% to 1% of diastatic malt (based on the total flour) can be added to the final dough.
Preferments like poolish or sponge, sometimes generate lower levels of fermentescible sugars available at the end of the pre-fermentation time. In certain cases, this can be used to our advantage. A higher quantity of preferment should be added to the final dough when working with a high level of enzyme in the flour (low falling number). By increasing the quantity of preferment, we increase the portion of the flour with less sugar available to the yeast. In doing so we reduce a lot the fermentation activity and the reddish crust color that is usually obtained when too many enzymes are present in the flour.
More liquid preferments like poolish, because of their liquid consistency, favor enzyme activity. Amylase, but also protease, will be more active during the pre-fermentation. As a result, higher extensibility in the final dough is obtained, reducing the mixing time of the final dough and preserving it from potential over oxidation. A better extensibility is also noticeable at the shaping stage. Higher volume and more open inside are also achieved in the final product.
Until Norma actually uses a poolish or modified-poolish to make a dough, we won't know for sure what she will need. I suggested that diastatic malt might be a solution to the color problem if it becomes an issue, but it could well be that using a standard form of sugar, or possibly a combination of such a sugar and diastatic malt, could be solutions to the problem.
BTW, diastatic malt is available from different sources, including Bob's Red Mill, as shown at http://www.bobsredmill.com/malted-barley-flour.html
. It is also available from Barry Farm, http://www.barryfarm.com/images/product/sugars/diastaticmalt.JPG