Saturday, April 21, 2012

The uncertainty of kneading.


In metrology, the science about measurements and its applications, a very important factor to consider in a measurement process, expressing the intrinsic reliability of the result, is called “measurement uncertainty”.
Without getting too much into the details of metrology, in order to avoid to bore the readers. I will try, obviously playing with the original meanings of this term in metrology, to apply the concept of uncertainty to a knead.

When I have started to ask myself the question:” Will my flour be proper for this dough ?”
(if you have never asked yourself this question, it's time to start to do it)
Trying to consider, beside the wheat flour type 00, 0, 1, 2 and whole wheat, also its rheological carachteristics. I have immediately understood that the some values used in the used in professional circle, were not furnished to the common consumer. Those values are the indices of W and P/L, That are calculated with a test made with a device called Chopin alveograph. They respectively show the strenght, the elasticity and the extensibility of the dough made with a flour.
Unfortunately often on the flours that we find on the shelf of the shops this value are not suitable. More easily, are given from the producers values that show the nutritional characteristic of the flour, that are: the percentage of proteins, carbohydrates, fat and many others, contained in it.
A method simplified for selecting the proper flour for your dough consist in consider the percentage of the proteins contained in the flour.
Usually, more higher is the percentage of the proteins contained in it, more higher the values W and P/L will be. This theory is good for sure for flours of the types 00 and 0. In others types of flours, where the amount of fibers contained is higher, the flours type 1, 2, and whole wheat. The value of percentage of proteins, could be elevated despite low levels of W and P/L, because of the presence of a great quantity of fibers. Actually, whole wheat flours are usually more difficult to knead despite their high content of proteins. Somehow, with the due “uncertainty”, we can say that an high content of gluten, that in the professional circle will be associate with an high value W, could be contained in a flour with high percentage of proteins.
Which are the factors that produce "uncertainty" in our summary evaluation?

  • The informations found on the label of the flour.
  • The type of cereal from which the flour is drawn: wheat, durum wheat, Kamut, spelt, rye etc.
  • The type of the flour: 00, 0, 1, 2 and whole wheat.

However, besides these preliminary evaluations, I prefer to base on my direct experience and eventually to take note of the results gotten with every flour that I use. Starting to the better amount of water to use, arriving to the times of kneading and rising, That can be different, depending from the type of flour and kneading.

Those are my sweet woven focaccine,
made with organic wheat flour type 0