11. Possibilities of Influencing Milled Rye Products
In the past, baking technology was directed solely towards combating sprouting. We have to take this into account when reading older literature and the recommendations such works give. In many cases out-of-date recommendations have been accepted without further thought for processing today's milled products.

In recent years, millers and bakers have gladly accepted improved raw materials and integrated them into their quality systems with correspondingly adjusted data. For example, the standard values for Falling Numbers and/or the Amylogram most often used for characterizing the value of the product for processing have constantly been raised. Because of this, lots with balanced enzymatic effect were often rejected, or the mills had to treat the flour in order to achieve the values stipulated in the contract. It was found that treatment of the flour with enzymes can change the Falling Number and Amylogram data, but it does not necessarily have a positive effect on baking properties. Rye with "natural" Falling Numbers between 120 and 150 s usually produces the best results, provided that the dough does not soften too much.

Even now, many bakeries still use multi-stage sour-dough processes, whatever the reason may be. Such processes used to be a reliable way of achieving good bread quality with highly enzyme-active milled products that break down readily. In these and some other sour dough processes, work is carried out in single steps with large quantities of starter (30% or more). The very acid conditions when a new sour dough starts to ferment reduce enzymatic conversion.

Milled rye products need sour dough to this day, not necessarily to achieve an even, elastic crumb but chiefly to form flavour components or their precursors, i.e. to enhance the taste of the bread. It is still not possible to separate acidification from flavour synthesis in the sour dough. Since the sour is so important as a source of flavour, the pre-doughs used should be correspondingly reactive. In order not to overdo acidification, it is advisable to work with sour doughs made overnight with a moderate proportion of starter and with a relatively low starting temperature and a high dough yield.

We therefore recommend one-stage sour-dough processing with:
• 5 to 10% starter (based on the amount of flour or meal in the sour dough);
• a dough yield of about 180 - 200% (or higher if it is to be pumped);
• an initial temperature not exceeding 25 °C in the sour dough;
• fermentation times of 14 - 18 h.

Although this sour dough should be used within one day of being prepared, it can be kept for up to 48 h without refrigeration if its temperature does not exceed 28 °C. If this presents a problem in the hot summer months, it is advisable to start at a somewhat lower temperature or to use the sour dough within 8 to 12 h of its maturing or to refrigerate it after this time. Bread doughs should be processed as soft as the dough properties allow, and the temperature should be round about 28 °C. The quantity of yeast should be no more than 0.5 to 1.0% in rye bread and about 1.5 to 2.0% in mixed wheat and rye bread to achieve good leavening without too rapid fermentation. The amount of yeast needed naturally depends on the resistance of the yeast to acid, which means that the above figures are only a guide.

When rye flours that break down readily are baked, it is not necessary to make changes to the dough processing steps (including shaping) and fermentation. If only a small amount of yeast is added the dough resting time is slightly longer, but the final fermentation time can usually stay as it is. To achieve a soft, moist crumb it has proved an advantage to choose a hotter and slighter shorter baking regime or to make hearth bread or pan loaves. Acidification measures, dough yield and the baking regime remain the most important criteria for achieving a properly elastic crumb that is not too moist and does not roll into a ball – i.e. pleasanttasting, moist bread with a good shelf-life.

12. Summary
The aim of this contribution is to show how important the properties of milled products are even during preparation of the dough. It includes references to characterization of the rye, not only on the basis of its behaviour during the hot phase of baking but also in the cold phase, i.e. during the dough processes. The Rye Viscosity Test may be recommended as a simple method of describing the dough properties of rye for baking purposes more reliably, with emphasis on bread and other small baked products leavened with yeast and/or sour dough.


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