I am trying to duplicate a recipe which uses malted flour as well as regular bread flour--but it doesn't give the proportions of each. I know that malted flour has more diastase activity--what effect does it have on the final proofing? Should I reduce the time that I proof in order to prevent over-proofing? In my one attempt at this, I used 10% malted flour, and my usual proofing schedule, and the bread was a bit over-proofed and didn't have much oven spring. Any suggestions will be appreciated.
First I would ask why the malt is in the flour in the first place. I know of 2 reasons and my description will be from a layman's perspective.
Mills strive for consistency in every bag of flour that they sell. This can be difficult to achieve due to the ever-changing nature of the grain they mill. As an example, just because the wheat is of the winter variety every time doesn't mean that each harvest will have all the same factors needed for uniform performance.One standard that mills use is called falling number or falling time. You can read more about this by searching the web, but in a nutshell it is a test of specific amounts of flour mixed with water, followed by placing a weighted device in the mixture. The amount of time it takes for this calibrated device to "fall" through the mixture is the falling time, and this time is then converted into a falling number. Every newly milled batch of flour will have a different falling number so the mills use diastatic malt to adjust the batch. In this way they can adjust the falling number to within a specific range so that the baker is not forced to chase performance differences.
Bakers use diastatic malt for a couple of reasons. One reason is similar to the description above - to change the performance of the mixture. By adding diastatic malt, maltose is provided as a nutrient for the bacteria in a sourdough formula. The bacteria breakdown the maltose and in the process produce fructose that can be digested by the yeast. Essentially malt is added as a nutrient for the processes in fermentation. Another reason bakers use diastatic malt is that it changes the color of the crust and the crumb, due to the sugar residue. If used properly ( a little goes a long way) the crust will take on a dark red hue which some people prefer. The problem is that the crumb begins to take on an ashen grey color if too much diastatic malt is used.
So, first you have to discern why the malt is in the formula in the first place, then you can decide how you might adjust accordingly.
Jim
we call sprouted flour in the USA. It is faster to ferment and proof and takes a bit less water,