Sourdough management
The sourdough process is the production of a sourdough in one or more stages. It is controlled by selecting the raw material, the microorganisms, the dough firmness (including water content), the number of stages, the temperature and the maturing time.
Classification of sourdough
Sourdoughs are drawn with different goals, with processes and microorganisms producing different types of sourdough. Böcker u. a. proposed a classification in 1998, which is now used in practice and literature.
| Type 0 | Type I. | Type II | Type III | |
| Yeast | Baker's yeast | Sourdough (ongoing tour) | Sourdough (ongoing tour) | pure bacterial culture or sourdough |
| Raw material | wheat | Wheat / rye | rye | Wheat / rye |
| guide | single stage 3–24 h | 4-16 h at 25-35 ° C | 1–7 d at> 28 ° C | - |
| Microflora | Baker's yeast dominates, lactic acid bacteria low | Lactobacilli, sourdough yeast | Lactobacilli dominant | - |
| End pH | pH 3.5 to 5.0 | pH 3.5 to 4.0 | pH 3.2 to 3.8 | - |
| Acidity | low acidity <7 | medium acidity 5–20 | high acidity> 20 | - |
| Suitability as an item to be placed on | not suitable | suitable | not suitable | conditionally suitable |
| Baking effect | Yeast plant, product quality | Shoot, acid formation, product quality | Acid formation, product quality | Dough acidification, starter cultures |
Type 0
Type 0 is made with baker's yeast, whereby acid formation is not the goal. The aim is to accelerate yeast growth, improve dough properties and improve the sensory properties of the product.
It is exclusively about wheat dough, which is not kept continuously and freshly prepared every day. These doughs are to be counted among the pre-doughs . Their microflora and the resulting baking properties clearly distinguish type 0 dough from (wheat) sourdoughs. If the dough is left to stand for a long time of 8-16 hours, lactobacilli develop in these doughs, which means that they can then be classified as sourdough.
Type I.
Type I doughs include the classic three-step sour, which is made continuously, but used after a maximum of 16–24 hours. They are used for leavening and loosening dough. The three-stage leadership requires more specialist knowledge and accurate work. This type of leadership is very labor-intensive.
Type II
Type II doughs are also fed continuously, with parts being used as items to be placed. In practice, these sourdoughs are used to acidify the dough, to improve its aroma or to produce dried sourdoughs with a high degree of acidity.
Compared to type I doughs, these sourdoughs are made for longer periods of time, up to a week. They are kept very warm with an initial temperature of 30 ° C. The long fermentation results in temperatures above 40 ° C, which means that the microflora is subject to considerable changes. Only acid-tolerant and thermophilic organisms such as B. Lactobacillus pontis, Lactobacillus panis, Lactobacillus frumenti or Lactobacillus reuterti are viable in this environment. Metabolically active lactic acid bacteria and sourdough yeast die off, so a sufficient impetus effect is not guaranteed. Kahm yeast only occurs in irrelevant germ counts.
Type III
This group includes dried sourdoughs with active microflora. These sourdoughs are used as starter cultures and for souring dough.
Microorganisms in type III dough are not selected via the fermentation conditions, but are specifically inoculated. High numbers of bacteria from pure bacterial cultures are used. The cultures were selected to be resistant to drying and storage.
Sourdough management and fermentation
The classic three-step guidance was labor-intensive and prone to errors. Ways to simplify it while maintaining the bread quality were therefore sought.
In contrast to pre-dough , sourdoughs are made over a longer period of time. During the professional tour, the number, standing times and temperature of the individual levels and the respective amounts of water and flour are varied in such a way that the baker's goals (type of pastry, time of baking, design of the work processes in the bakery) are optimally achieved. Today fermenters are mostly used in which the parameters mentioned can be set separately. In the literature, fermentation is also used for the term (dough) management .
Classic three-step guide
The desired organisms are specifically promoted at the individual levels. The required lactic and acetic acid are formed and sufficient yeast for the shoot is increased.
1st stage freshly sour (yeast propagation)
- Dough Yield (TA): 200-220
- Temperature: 25-26 ° C
- Maturing time: 5 to 8 hours
2nd stage basic acidity (formation of acid and aroma)
- Dough yield: 150-170
- Temperature: 23-28 ° C
- Maturing time: 6 to 10 hours
3rd stage fully acidic (shoot development)
- Dough yield: 180-200
- Temperature: 25-32 ° C
- Maturing time: 3 to 10 hours
Dinkelsauer
Dinkelsauer is managed in one stage. Its aim is to grow enough yeast for loosening. A pure starter culture (pure breeding sour) is necessary because spelled does not tolerate acid well. This is disadvantageous because significantly more acids are formed in sourdoughs made from wholemeal and dark flour types.
The sour is soft (TA 200) and matures for up to 18 hours at a temperature of 28 ° C. It can be stored refrigerated for two days and unrefrigerated for one day.
Berlin short tour
This sourdough production was developed in 1942 by Paul Friedrich Pelshenke (1905–1985). It is a single-stage sour that is kept warm and soft. The aim of this tour is to build up acid quickly. The workload is low and roughly corresponds to a wheat sour . This tour promotes the formation of lactic acid, which creates mildly aromatic rye bread. Yeasts are less promoted, which means baker's yeast or wheat sourdough is required for loosening.
To achieve this goal, a high proportion of 20% of the rye flour is required and 50–70% of the rye flour is acidified. At a temperature of 35 ° C and a dough yield of 190, the maturing time is 3 hours. At low temperatures, the maturing time increases by 15 minutes for every ° C below 35.
Monheim salt acid process
This process was developed in 1958 from the Berlin Kurzsauer. Originally 5% salt (calculated from the sourdough flour) was added to the sour. The result was not convincing in terms of taste. It was only with the “New Monheimer Salt Sour Process” that standing time tolerance, good baking results and a well-rounded bread aroma were guaranteed (von Stein 1971). Even with this tour, the workload is low. Baker's yeast is required.
- Sourdough content: depending on the type of bread, 30–40% of the amount of rye flour
- Sour sour: 20% of the amount of sourdough flour
- Salt: 2% of the amount of sourdough flour
- Dough yield: 200
- Sour dough temperature: from 30–35 ° C to 20–25 ° C
- Maturing time: 18 to 24 hours
- Standing time up to 3 days
Detmold three-stage tour
The Federal Institute for Grain, Potato and Fat Research in Detmold, today the Max Rubner Institute, Federal Research Institute for Nutrition and Food (MRI), has optimized the disadvantageous three-step process and made it more practicable.
This tour was developed from the Detmold two-stage tour. The sourdough matures for 24 to 30 hours, eliminating the need for evening work. It is precisely this point that is disadvantageous in traditional leadership. The third stage is run as a refresh stage, in which yeasts are particularly favored. This results in a good taste of the bread.
1st stage: freshening sour
- Dough yield: 250
- Sour dough temperature: 25–26 ° C
- Maturing time: 6 hours
2nd stage: basic acidic
- Dough yield: about 163
- Sour dough temperature: 30 ° C
- Maturing time: 15-25 hours
3rd stage: fully acidic
- Dough yield: about 190
- Sour dough temperature: 28 ° C
- Maturing time: 3 hours
Bread dough
- Dough yield: about 178
- Dough temperature: 28-29 ° C
- Dough rest: 10 minutes
Detmold two-stage tour
The Detmold two-stage sour is quite robust and can be used for a long time. So he can z. B. mature from Saturday to Monday without the need for refreshment. It is a "Grundsauer overnight tour", offers a good (also economical) alternative to the three-stage tour. The refreshing acid level does not apply to this tour. Ordinary yeasts are preferred at this stage.
During the development, experience played a role in the fact that the shoot of a multi-stage sour is often insufficient and additional yeast is necessary. For example, baker's yeast is also added to the Detmold two-stage route.
1st stage: basic acidic
- Dough yield: 150
- Sour dough temperature: 23-27 ° C
- Maturing time: 15-25 hours
2nd stage: fully acidic
- Dough yield: about 180
- Sour dough temperature: 28 ° C
- Maturing time: 3 hours
Bread dough
- Dough yield: approx. 178
- Dough temperature: 28-29 ° C
- Rest time: 10 minutes
Detmold one-step tour
The Detmold one-step sour is usually set at noon or before work. With a maturing time between 15 and 24 hours, this sourdough preparation is well suited for “full sour dough overnight”. Another advantage is that its storage tolerance means that several types of dough are possible during the working day. It is therefore quite widespread. Yeast must also be added during this tour.
- Dough yield: 180
- Sour dough temperature: 26–27 ° C (or 30 ° C falling to 24 ° C)
- Maturing time: 15-25 hours
Weinheim quality sourdough
The Weinheimer quality sourdough developed at the Akademie Deutsches Bäckerhandwerk Weinheim is based on the Detmold one-step guide, which was developed shortly before by the scientists at the Federal Research Institute for Grain Research in Detmold (today: Max Rubner Institute, Federal Research Institute for Nutrition and Food ). However, the Detmold single-stage management was originally based on a constant temperature, which was easy under the laboratory conditions in Detmold, but difficult in practical bakeries.
As a result, the Federal College of the German Bakers' Crafts (today: Akademie Deutsches Bäckerhandwerk Weinheim ) developed and published the practical and widely used Weinheim quality sourdough for the industry in the 1970s. The day before, a mixture of 100 parts of rye flour and 80 parts of water with starter (ripe sourdough, 10% based on the rye content) is made at a temperature of 27 to 28 ° C. The temperature drops to normal room temperature of 23 ° C during the 16-hour ripening period. Earlier versions of the Weinheim quality sourdough were made with 2% pitch and up to 40 hours standing time.
The Detmold single-stage sourdough was later switched to a falling temperature during the standing time, so that the differences became blurred.
Foamy
After the Second World War , countless production facilities lay destroyed on the ground. The supply of yeast from yeast factories or breweries to the bakeries was poor. The foam acid process was developed by master baker Lubig (Bonn) out of this deficiency. The sourdough was guided very softly over five stages and stirred vigorously (whisk) so that enough air comes into the mixture, which is necessary for the yeast to multiply. Otherwise the yeast would stop reproducing and produce alcohol. Foam was formed, which gave the process its name. Although supplies were guaranteed again a few years after the war, some bakers stuck to this method. On the one hand, there was no need for expensive yeast, on the other hand this process produced a mildly aromatic sour bread. It is now common again in organic bakeries, as it is baked without the addition of yeast. The foamy sour process is quite uneconomical and time-consuming, since the sourdough has to be supplied every three hours.
In 1949 Lubig set up guidelines for foam acids, on which today's optimized processes are based.
- During the preparation process, almost the entire bulk quantity of water is used for the sourdough preparation. This is beneficial for starch gelatinization, which has a positive effect on the structure of the crumb.
- The sourdough is made very soft in all phases (TA 300) in order to encourage yeast to multiply.
- The optimal temperature is 22 to 24 ° C.
- The mass should be mixed with as much air as possible so that it becomes frothy. The oxygen supply to the yeast is improved and volatile acids are removed mechanically.
- Round sourdough containers are preferred to ensure a good stirring and whipping effect. So that the sourdough can "breathe", whereby volatile acids evaporate, it should not be covered.
- The pitching time is created from 0.5 to 1.5% of the total amount of flour. The acid required is set in this area. It is not the amount of acid but its quality that determines the quality of the bread.
- For the sourdough, 40 to 50% of the amount of rye flour is recommended. In the last stage, a TA of 200 is aimed for, the temperature of all stages being optimally 23–24 ° C (maximum 25 ° C). Under these conditions, yeast reproduction is promoted and acid formation is reduced.
Level 1–3
- Dough yield: 300
- Temperature: 22-24 ° C
- Maturing time: 3 hours
Level 4
- Dough yield: 215
- Temperature: 22-24 ° C
- Maturing time: 8 hours
Level 5
- Dough yield: 265
- Temperature: 30-32 ° C
- Maturing time: 3 hours
Combined tour
As early as 1931, the IREKS company developed the first dried sourdough (contained living cultures) with a high degree of acidity and swelling flour . Since large amounts of it had to be added, other baking agents were developed. These contain one or more edible acids (citric acid, lactic acid, acidic organic or inorganic substances) and other ingredients that are effective in baking. The annoying preparatory work of sourdough guidance is eliminated and direct guidance is guaranteed. Since there are no metabolic products from sourdough production, such products cannot convince in terms of taste and freshness.
This resulted in the combined tour, in which part of the rye content is acidified to form a basic acid. This basic sour is kept fixed and changes little after 15 hours, which means that production is flexible, as different types of bread can be made in any time period. In addition to an acidic baking agent, yeast is also added.
- Queuing time: 10%
- Dough yield: 150
- Temperature: 23-28 ° C
- Maturing time: 15 to 24 hours
Only a small amount of acetic acid is formed compared to other guides, which means that the acetic acid note in the end product is not very pronounced. A bread may only be declared as sourdough bread if at least 2/3 of the acid comes from the sourdough. To meet this criterion, 30% of the rye flour is acidified. This leadership is most widespread in Germany today.
Others
- Liquid sourdough (1-stage)
- Two-stage sourdough production
- Ulmer Sauer - three-step tour
literature
- G. Böcker, P. Stolz, WP Hammes: New insights into the sourdough ecosystem and the physiology of the sourdough-typical strains Lactobacillus sanfrancisco and Lactobacillus pontis . In: Grain Flour and Bread. 49, 1995, pp. 370-374.
Individual evidence
- ↑ Gottfried Spicher [founder], Markus J. Brandt, MG Gänzle (ed.): Handbuch Sauerteig. Biology, biochemistry, technology . 6th edition. Behr, 2006, ISBN 3-89947-166-0 .
- ↑ a b Josef Loderbauer: The baker's book in learning fields . Verlag Handwerk und Technik, Hamburg 2008, ISBN 978-3-582-40205-9 .
- ^ Claus Schünemann: Learning fields of the bakery - production. Gildebuchverlag, Alfeld 2011, ISBN 978-3-7734-0165-6 .