6.2.3. Volume Yield
The volume development of rye bread is fairly limited. The average
value is about 300 mL/100 g of rye flour with fluctuations of about ± 10%
depending on quality. So with rye the differences in bread volume between
varieties are considerably smaller than with wheat, where they are about ± 150
mL/100 g – in other words about 25% – in wheat flours of the type 550. Because
of the slight differences, volume was long considered fairly unimportant for
the baking value of rye. It does, however, have a decisive effect on the
properties of the crumb and on shelf-life.
6.2.4. Elasticity of the Crumb
An important attribute for rating the quality of rye bread is the
elasticity of the crumb. A technological objective is to produce a crumb that
is moist and pleasantly cohesive and binding and at the same time elastic. In
milled rye products, poor crumb elasticity usually only occurs in the case of
rye whose constituents have an increased tendency to break down
("sprouting"). But poor crumb elasticity may also be a result of
processing, e.g. excessive dough yields, too little acidification, very high
volume due to extra ingredients, inadequate baking etc. Raw materials that do
not break down readily (with high Falling Numbers or Amylogram values),
over-firm dough processing or conditions that aggravate both these weaknesses
(e.g. too little swelling of the constituents of the rye during processing of
the dough, too little pre-dough, i.e. sour) result in a firm crumb, reduced
inflation and thus poorer keepability of the baked goods. Such disadvantages
have often occurred in the past ten years.
6.2.5. Quality Number
The calculation of a Quality Number takes account of efforts to
achieve resistance to sprouting, which were dominant for a long time, and also
dough properties.
On the basis of baking tests with sour dough, the dough yield, the
volume yield and in particular crumb elasticity were included. This basis for
evaluation was then extended to cover further criteria, such as dough
properties, and a new description and classification of quality. The new
characterization system was already used in the Walsrode Test.
7. Walsrode Test
In 2000 a test was carried out in cooperation with Förderverein
Pflanzenbau e.V. in Walsrode. Some of the trial fields of rye were threshed at
the usual – presumably optimum – harvesting time, whereas the rest were
threshed about four weeks later. The quality parameters changed as follows
between the first and second harvesting dates (Tab. 71):
 |
| Tab. 71: Quality values for rye harvested at different times under
otherwise identical growing conditions |
It was no surprise to the initiators of this test that the rye and the
flours (Type 997) produced by the standard milling method from the second
harvest had superior baking properties. Because of their lower (but more
suitable) rheological values, these products were in a better range for baking.
However, the highest Quality Number, 5.00, was not reached since the volume
achieved even with the samples from the second harvesting date was still
limited. Points were deducted because the resulting crumb lacked optimum
moisture and soft, elastic properties, and therefore optimum shelf-life.
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