Detailed Lot Information
Understanding Flour Analysis: How to Harness the Advantages of Information
Consistent Flour?
We at Cook Natural Products feel strongly that varietal grain selection, identity-preservation and full disclosure of laboratory analysis are the factors that allow us to provide flour especially suited to bakers for whom quality is a primary concern. Our job is to make sure that appropriate grain is grown, segregated, (blended if needed), milled properly and transported efficiently. The manner in which we manage that process is designed to provide not only consistency, but specific quality. Identifying desirable characteristics, and finding the grain that exhibits those qualities is an ongoing process for us. Please understand that no matter how well we do our job, no two lots of flour are identical. The only way to predict the effects of flour variations on your products, is to learn how to read flour analysis sheets.
Now that we are providing flour analysis for every lot of flour that we sell, we have realized it is time to help educate bakers about exactly what those analyses mean. Brewers, and wine-makers have numerous advanced sources of objective data concerning every aspect of what they do. They also have the references and educational resources to allow them to understand that information. Cook Natural Products hopes to help bakers by improving their flour literacy.
Below are some helpful details of the typical points of our analysis sheets:
Mill Date
The mill date indicates just that: the actual date that the flour was milled. It is important for the baker to know the age of the flour on the floor. White flour is thought to be “mature” three to four weeks after milling. During that time, certain biochemical and oxidative changes occur that result in flour with optimal baking characteristics. If stored in a dry, clean area at 70-80° F. shelf-life is easily 24 months. Because of the high lipid and lipase concentration in whole-grain flour, we recommend use within four to six weeks of milling in all whole-wheat and whole rye.
Lot Number
The lot number always printed on the bag is used as the reference for a particular lot/mill-run. Cook Natural Products lists all flour specifications by the lot number. In most cases the lot numbers refer in some way to either the mill, or pack-date.
Organic Certificate
Indicates the certifying agency for the flour.
Wheat Type
Wheat is generally classified by describing three different parameters: kernel hardness, kernel color, and growing condition. The four main categories are: hard red spring (HRS), hard red winter (HRW), soft red winter (SRW), and winter and spring white wheats.
Wheat Variety
Indicates the name of the specific wheat variety. Cook Natural
Products is always gathering data and feedback so that we can help our
farmers make better choices about the wheat varieties that they plant.
We believe that being a conduit to communication between the growers and
end-users is integral to our goal of providing superior flour to the
baker.
Growing Conditions
Just
about all of Cook Natural Products’ growers farm wheat under dryland
conditions. This means that the grower does no irrigation, and is
subject to the vagaries of nature: drought, flooding, hail etc..
Irrigated wheat farming is usually dictated by climate. This is a
very expensive, and energy intensive method.
Wheat Protein
This figure is the protein content of the wheat
before milling. In general white flour will have a protein content
about one percent lower than that of the wheat. This figure will
change, depending on milling technique and extraction. This is the
main parameter for judging wheat quality in the conventional grain
market. Cook Natural Products takes the extra step of analyzing
the “protein quality” by running an alveograph test before milling.
Wheat Moisture
The
moisture of wheat is primarily of interest to the farmers and millers.
The price, storage-stability, tempering time and milling
characteristics are all affected by the wheat’s moisture content.
Tempering Time
Tempering is the process of adjusting the moisture content of wheat.
At the mill, after the wheat is cleaned of dirt, foreign seeds, chaff
etc., the wheat is tempered. The wheat is moistened and left in
rotating drums until the moisture content is 17-19 %. Sometimes
the wheat is heated/steamed to hasten tempering. Tempering
optimizes the separation of the branny covering and germ from the
endosperm. Tempering also makes the endosperm less liable to
starch damage.
Flour Protein
Traditionally flour protein has been the main parameter used to judge
flour quality and strength. Today we know that not all wheat
protein is created alike. Wheat albumen, (protein) is composed of
four types of protein: gliadin, glutenin, albumin and globulin.
Gliadin and glutenin comprise roughly 85% of the albumen, and are the
gluten-forming components. Albumin and globulin are water soluble, and
thus don’t add to the strength of the flour. The percentage of protein,
(albumen) only tells us the amount of protein, and is only a hint as to
the real character of the flour. This figure does not tell us
anything about the type, or quality of protein. The alveograph
test gives us more valuable information about the “quality” of the
protein; and thus how it will perform in the bakery.
Flour Moisture
The
level of moisture in flour is important mainly for the issue of storage.
When the moisture level exceeds 15 % the shelf life of the flour is
greatly reduced. Generally, the moisture will be 12-14%, which
when stored in appropriate conditions, (relatively cool, dry and
aerated) allows for plenty of shelf life.
Flour Ash
The
ash content of the flour is determined by incinerating a sample of
flour. The minerals naturally present in the flour do not burn and
remain as ash. The weight of the ash is then compare to the
original sample. The ash content tells us something about the
extraction of the flour. In the endosperm of the wheat kernel, the
mineral content increases from the center outwards. The area of
the endosperm nearest the aleuron and bran layers has the highest
mineral content. Higher ash contents indicate higher extraction.
Cook Natural Products aims for an ash content of about .55% in our white
flours.
Falling Number
The
falling number test determines the alpha-amylase activity of a flour
sample. The test entails heating measured amounts of water and
flour in a special tube. The tube is placed in a boiling water
bath and stirred with a plunger until the sample is gelatinized.
Then the plunger is placed on the surface of the sample, and the time
that it takes the plunger to sink to the bottom of the tube is recorded.
Depending on the alpha-amylase activity, the degradation of the starch
paste will vary. The higher the alpha-amylase activity, the lower
the number, and vice versa. Typically the falling number has to be
adjusted through the addition of diastatic malt, or fungal amylase.
Such adjustments are usually done at the mill, along with the enrichment
package. Our organic flours are un-malted, so they have high
falling numbers, generally in excess of four hundred. Malted bread
flours have falling numbers of: 250-290. Generally the baker will
find that fermentation progresses more rapidly as falling numbers become
lower.
Farinograph
The “Brabender
Farinograph” is one of the most common flour testing machines in use
today. The farinograph produces a graph that represents the force
required to turn two mixing arms in a small mixing chamber with dough at
an adjusted hydration. On the graph each vertical line represents
thirty seconds. The horizontal axis spans 0-1,000 brabender units;
each line marking 20 BU, (i.e. force/resistance). The key points
of record on the graph are as follows:
Arrival Time
Indicates
the interval between zero minutes and the point at which the top of the
curve first intersects the 500 B.U. line.
Departure Time
The
time from zero minutes, to the point when the top of the curve leaves
the 500 B.U. line.
Peak
The
peak is the time interval between zero minutes and when the curve
indicates maximum resistance. In general lower peak times
correlate with lower flour protein and absorption.
Stability
The
difference between departure time and arrival time.
Absorption
Dough
hydration is adjusted so that the peak of the graph is centered on 500
BU, resulting in a predetermined dough consistency. The absorption
indicated is the adjusted hydration. When looking at farinograph
absorption it is important to realize that this is not an absolute
value. The greatest value can be had from comparing absorption
values from lot to lot, and making adjustments proportionately.
MTI
Mixing tolerance index is the difference in BU, from the top of the
curve at the peak to the top of the curve measured at five minutes after
the peak. Higher MTI numbers indicate greater mixing tolerance.
TMD (Twenty Minute Drop)
Represents the difference in B.U. from the 500 B.U. line to the center
of the curve measured at 20 minutes from the addition of the water.
Starch Damage
Inherent
characteristics of the wheat, along with the physical effects of milling
determine the level of starch damage. The process of wheat milling
damages a portion of the starch granules. This tendency is
amplified as the hardness of the wheat increases. Because of this,
starch damage is of particular concern here in North America.
Starch damage increases the amount of fermentable carbohydrate as well
as the absorption of the flour. Normally starch granules absorb
one-third their weight in water, when damaged that increases to 2-3
times their weight. Damaged starch granules are very susceptible
to attack by alpha-amylase enzymes. The combination of high levels
of fermentable carbohydrate, and water, (and thus rapid enzymatic
activity) make conditions optimal for more active fermentation as the
damaged starch levels increase. Also, though flour with high
starch damage figures absorbs a lot of water, once the amylase enzymes
do their work, the dough becomes slack. Balance, as always, is
key. Too much starch damage, and the dough tends to be slack and
over-fermented; too little and the fermentation stalls after the
immediately available sugars are consumed. One should expect to
see starch damage at 6-9% for winter wheat’s, and 7-10% for spring.
Damaged starch significantly affects both Farinograph water absorption,
and dough extensibility and resistance (Alveograph).
Alveograph CH (Constanct Hydration)
Produced by Chopin, the Alveograph is an instrument that gives valuable
rheological information about a dough sample by measuring the pressures
attained during the inflation of a dough sample into a bubble.
Because the test expands a dough sample in a biaxial plane, similar to
the way dough cells expand in actual bread dough, this test is highly
regarded.
W
Also
known as, “the deformation energy”, the W represents the
force required to inflate the dough bubble until rupture.
Literally the W is the area under the curve on the graph,
multiplied by a factor of 6.54. This value generally indicates the
overall baking strength of the sample. The water absorption is
generally thought to increase as the W increases. Loaf volume is
also thought to increase as the W value rises. Bread
flour W values tend to be 200+, with number up to 400
being especially appropriate for dough undergoing long fermentation
times. Along with the numerical figures, it is important to
actually see the drawing of the curve. Using the drawing along
with the other Alveograph values, gives the baker the greatest chance in
predicting flour performance. There is great value in compiling
drawings and data along with real-world impressions of flour over time.
Only in this way can rheological testing data be put to its greatest
use.
P
Also
known as the overpressure, the
P is the maximum
height (h) in mm. on the alveogram multiplied by a factor of 1.1.
This figure represents the viscosity, tenacity, or even strength of the
sample. The AACC defines overpressure
P as an
indicator of dough resistance to deformation. As
P
rises, so does the resistance. Some also believe that
P can be taken as a measure of the hydrating capacity of the sample.
Because the maximum height is effected by the type and thickness of the
dough, some researcher believe that the ratio of the height of the curve
at the bubble volume of 100 ml (P100) to the height of the
maximum (Pmax) provides a better correlation with
potential loaf volume.
L
Hamed
Faridi and Vladimir F. Rasper write in, “The Alveograph Handbook”: “The
average abscissa to rupture, L, is the average length, in
millimeters, of the quintuplet curves from the point where the dough
bubble starts to inflate to the point where the bubble bursts and the
pressure drops suddenly. Unlike overpressure
P, the
meaning of this index seems to be unambiguous.
L is
commonly used as a measure of dough extensibility.”
P/L
This
ratio is thought to indicate general gluten performance. In other
words the balance between dough elasticity and plasticity. In
general values of 0.40-0.90 are thought to be appropriate for bread
baking. As the number rises, there will be a certain point where
the dough will be too elastic/resistant, yielding a less developed loaf
with compact crumb. Conversely, when very low P/L values indicate
a dough that is too extensible. There is no absolute perfect
value. Finding a balanced value that is appropriate for the
application is key.
B-Value
The
B-Value figure gives information about the color of flour. Color
definitely determines the crumb color of bread; but also gives clues
about: flour grade, bleaching and granularity. Cook Natural
Products utilizes no chemical bleaching methods. Because of this,
and our milling methods, customers can expect to find our flour to have
a distinct creamy/yellowish hue.