There is Gluten Washing that you can do to test and have a reference compar=
ison with flours that you do know are of higher &/or lower protein content.
Wheat contains four different proteins: albumins, globulins, gliadins
and glutenins. Two of these proteins when mixed with water form
gluten. The visco-elastic properties of gluten are responsible for
the structure of bread. Hard wheat flour with a protein content of
around 11% (strong) is more suitable for baking bread. Gluten washing
was first developed as a test of the baking quality of flour over 100
years ago and is still used to determine gluten content*.
Try this test*:
Bread Flour
All-Purpose Flour
Water 770F
* Bakers flour is available in most supermarkets.
* All-purpose flour is usually a blend of low protein hard wheat
and White soft wheat.
Use these flour & water amounts:
100g Bread Flour AND 50-55 mL of water and
100g All-Purpose Flour AND 40-45 mL of water
Procedure
In a small container add 100g Bread Flour and add 50 mL water. In
another container add 100g All-Purpose Flour and 40 mL water.
Mix each container's contents into a dough ball approximately 1
minute (should do the entire process from here on out one container
1st, then after gluten wash, do the other container). If the dough is
too dry add a little more water just a small amount at a time, if
it's too wet add a little flour a small amount at a time. When a nice
even dough ball is achieved and the dough ball can be worked (think
play-dough ball firm) run a tap with slow trickle of cold water. Work
the dough under the water, moving it between the thumb and fingers,
trying to keep the dough mass together.
As the dough is worked the starch will be washed out.
A strong gluten mass similar to chewing gum will form with the bread
flour (the higher the protein content, the greater the gluten ball).
At the end of washing, the gluten will stick together and it will
have a glossy appearance that is slightly yellowish/grey in color.
With the All-Purpose Flour, the gluten formation will be weak. The
ball will fragment very easily, and it will not have the same glossy
appearance*.
*I used a method as described by the "Riverina Environmental
Education Centre" website. However, I personally did this test
myself as shown to me at the American Institute of Baking back in the
mid-90's. When I did the gluten wash test in the labs at AIB we
actually had small containers full of water in which we worked the
dough balls. As we worked the dough balls in the containers, the
water became murky. We would then dump the water, refill the
containers with fresh water, and continue to work the dough balls
until only the gluten balls were left. At the lab we actually baked
off the gluten balls and it was really cool to see the dough balls
swell up into much larger hollow bubble-balls!
FYI, I wanted to clarify that "Vital Wheat Gluten" is pure gluten
therefore 100% protein. I believe Dale was referring to High-Protein
Flour of some sort with "ADDED Vital Wheat Gluten".
Dave J in California....in the Motherlode to be specific...23 year
veteran of 6 large scale bakeries...