Equipment for Testing the
Fermentation of Doughs (Maturograph) and the Increase in Volume During the
Baking Process (Oven Rise Recorder)
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| Fig. 51: Maturograph for measuring dough stability during proving (source: Brabender OHG) |
The Maturograph (Fig. 51) has shown itself to be a useful instrument
for testing doughs in the fermentation phase. The device measures the increase
in volume of a piece of dough during proving. The dough ferments in an
airconditioned chamber. An automatic sensor draws the "Maturogram" in
the form of a curve throughout the proving time. This makes it possible to read
off optimum proving or the final proving time, proving stability, elasticity and
the dough level. The proving time for the piece of dough, which is normally
determined manually by the baker, can be made more objective by this equipment.
The advantage of the device is that a piece of the actual dough with all its
ingredients is tested. So the Maturogram can be regarded as a very practical measurement.
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| Fig. 52: Oven Rise Recorder for measuring the increase in the volume
of dough pieces during the baking process (source: Brabender OHG) |
The Oven Rise Recorder (Fig. 52) is a very useful instrument for
documenting the increase in volume during baking. The dough is heated in an oil
bath from approximately 30 °C to 100 °C at the core. The resulting curve shows the
rise of the dough during heating. The diagram yields information on the
development of dough volume, the baked volume, the increase during heating and
the times at which gas escapes.
Baking Tests to Determine the
Quality Attributes of Rye Flours
The following baking tests are not as widely used as those for wheat
flours, since the indirect methods yield more information on the baking properties
of rye than is the case with wheat. Nevertheless, baking tests are performed
with and without acid, using classified rye flour and wholemeal rye flour.
1. Baking Tests for Hearth
Bread
Made from Classified Rye Flours This standard baking test can be
carried out with yeast, lactic acid or sour dough. In all three cases the rye
loaves are made as hearth bread. The yeast baking test can provide information on
the baking properties of the rye flours without the effect of acidification. If
lactic acid is added, the rating is carried out at slight acidification.
Product quality at optimum acidification can be ascertained in the baking test
with sour dough.
For both doughs, 1,000 g of rye flour, 1% yeast and 1.5% salt are
placed in the laboratory mixer (arm mixer). In these tests, too, the amount of
flour naturally has to be adjusted in accordance with the moisture content. In
the lactic acid baking test, lactic acid is added too. The temperature of the
dough should be adjusted to 29 °C; the prescribed mixing time is a total of 3
min. This is followed by a resting time of 30 min. The dough weight used is the
whole of the dough; proving takes place in fermentation baskets. Readiness for
the oven is a matter of experience; baking starts at a temperature of 250 °C,
falling to 200 °C. But with these small amounts of dough the temperature of the
oven is unlikely to change much, so at the end of the baking time a lower temperature
can also be achieved by moving the dough portions into a different part of the oven.
For the test with sour dough the dough yield is determined with the Farinograph
at 300 FU. The sour used is a "Berlin short sour dough" with 20% starter,
a dough yield of 190, a temperature of 35 °C and a maturing time of 3.5 hours.
If these parameters are adhered to, this one-stage sour dough process is just
as reproducible as the Detmold one-stage process. 45% of the flour should be
soured. The remaining procedure is no different from that of the yeast or lactic
acid baking test, but the pH and degree of acidity of the sour dough, the bread
dough and the bread crumb should be ascertained (Association of Cereal
Research, 1994).
2. Baking Test for a Pan Loaf
Made from Wholemeal Rye Flour For this test the wholemeal rye flour is
baked into a pan loaf as in the sour dough baking test. The dough yield is set
at 180. The oven temperature should be adjusted to a constant 210 °C. The evaluation
criteria are the same again.and the bread crumb should be ascertained (Association
of Cereal Research, 1994).
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