We are going to look at these parameters together because they tend to be
very common indicators of general flour quality but give only a little indication
of how the flour is going to perform throughout the bake. They are great
numbers to indicate whether you are getting the flour you think you need and
can serve as a first point of reference if you think there are quality issues
concerning your flour.

Moisture

On an analysis sheet this is a relatively simple number and is fairly meaningless
to you as a baker. But it does give an indication of the quality stability of the
flour as it was coming off the mill. Most moisture specifications read: ‘14%
Max’. This means that the flour does not contain more than 14% moisture as it
comes off the mill. This is important as flour containing moisture in amounts
greater than 14% will tend to mold and spoil at a much quicker rate than drier
flours. Flour is a hygroscopic material meaning that its moisture content will
tend, over time, to equilibrate with the humidity of the surrounding
environment. In damp conditions flour will absorb moisture from the
environment and in drier conditions will lose moisture to the environment. So it
is important to understand the time frame and storage conditions of your flour
and realize that this will affect not only its quality but also the quantity of
water that can be absorbed by the flour in the mixer bowl.



One final note, this moisture value is not indicative of flour absorption
as indicated by the farinograph results.

Protein

Bakers are typically only interested in the gluten forming proteins of their
flour. This measurement, however, is not a direct measure of gluten forming
protein content, rather it is the total protein content of the flour. However, it
can be used as a relative measure of the gluten forming protein content (ie the
greater the total protein content the greater the gluten forming protein
content). There has been much written about protein quality versus quantity.
The percentage of protein as indicated on your analysis sheet only concerns
quantity and really only serves as a general indication of the flour grade. The
chart above indicates the broad categories of flour grades and even this is
somewhat imprecise in that there is often a blurring of the lines between
grades.



It is very important to note that most protein values in the US are
reported on a 14% moisture basis whereas in the France and much of Europe
protein (and ash) is reported on a 0% or ‘dry matter’ basis. This is a powerful
tool and allows ‘apples to apples comparisons’ between flours that, as we
discussed above, may have different moisture contents. It can, however, lead
to confusion when you are talking about European flours and want to compare
them to US flours. Basically, reporting on a 14% moisture basis gives you a
corrected value of protein regardless of the actual moisture content. For those
of you who must know here is the formula used for the correction:

Protein 14% m.b. = Protein % as is x (100 - 14) / (100 - Moisture Content)

This same formula is used to correct ash content to a 14% or ‘dry matter’
moisture basis.

Ash

Ash is another one of those ‘relative’ indicators of flour quality and is best
used for ensuring the flour you are getting is the flour you want. The ash value
for a particular flour is a measure of the mineral content of the flour. A 100g
sample of flour is placed in an oven and incinerated at the temperature that
combusts all of the organic mater but leaves the mineral content of the flour.
This “ash” is weighed and then reported as the ‘ash content’ of the flour.



Most people use the ash value to determine how much bran has been left
in the flour after the milling process. This is an indirect measure of bran
content as there is some mineral content in endosperm as well. However, the
mineral content of the bran layer is some 20 times greater than that of the
endosperm. Therefore the ash value of a flour is a fairly good indicator of bran
content in that the higher the ash value the greater the bran content and the
darker the flour will appear. Bran in the flour also affects absorption. A higher
ash value will indicate more bran in the flour which will result in an increase in
absorption over flours with lower ash values.



As with protein, ash in the US is reported on corrected 14% moisture
basis and in France on a dry matter (0% moisture) basis. Again this is very
important to remember when requesting, say, a “T55” style flour from your US
supplier. The “55” refers to the ash content of the French flour but is reported
on a 0% moisture basis. So, throwing out all the other performance differences
of a European T55 flour, the same flour in the US would actually have an ash
content of approximately 0.46%.