Test Milling In Order To Obtain Flours For The Alveograph Test - Chopin CD1 Mode D'emploi

Instruction manual 
02/2017
Laboratory Mill CD1
3.1 Conditioning the wheat
■ Cleaning
The grain must be carefully cleaned and all foreign seeds (cereals
other than wheat and fodder plants), stones and metallic particles
removed. Cleaning is done either by hand - spreading out the
sample on a 0.50 x 0.50 m surface - or by an automatic cleaner.
■ Conditioning to obtain correct moisture level
❏ The amount and the distribution of moisture in the grain are
extremely important in order to obtain good milling as well as alveo-
graph test results. Thus, it is necessary to normalize moisture con-
tent at a fixed level by damping or drying and to obtain conditions
favouring the most homogenous distribution of moisture in the
grains as is possible. The simplest method is the so-called "cold
tempering" technique.
❏ The physical property of the grain kernel varies depending on
whether we are dealing with grains having a floury kernel or grains
with a vitreous kernel.
In the first case, the cross-section of the grain reveals a grainy
softish white structure.
In the second case, the cross-section, horny and amber-colored,
strongly resists any machine action.
There is of course an entire gradient of grains with an intermediate
structure (a floury part - a vitreous part).
Floury and vitreous grains obviously respond differently to milling,
especially with regard to the production of semolina and flour.
Consequently, two types of conditioning should be provided as is
done in industry:
- floury grain wheat: 16.5 % milling ~ 24 hr. resting.
- completely vitreous grain wheat: 17.5 -4 milling - 48 hr. resting.
- vitreous hybrid grains: 17.5 % milling - 24 hr. resting.
❏ The table in
appendix 1
500 g of grains varying in moisture content in order to bring the
water content to 16.5 % of 17.5 %.
The most common way of preparing wheat in order to obtain the
adequate moisture content is to put a sample in a 2-litre air-tight
flask and shake manually for several minutes in order to completely
distribute the water previously added with a graduate tube.
This method which has not been standardized in detail appears
much too rough when we think of the importance of this preliminary
test milling phase.
The addition of water is generally done in a most imprecise way. In
particular, the water is unequally distributed over the grain surface.
shows the amount of water in ml to add to
GB
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