The local yeast runs off

Goes great: organic yeast

Bread rolls, pastries, vegetable broths or spreads - yeast is found in more foods than you think. So far, the suppliers of natural food had to fall back on conventional yeast. Now it is also available in organic quality.

Wild yeasts occur everywhere in nature. The small plant organisms that count among the lower fungi are invisible to the naked eye. For centuries, yeasts such as beer, wine and baker's yeast with very specific properties have been grown from the native relatives. Yeasts need sugar and heat to grow. If both are present, the cells can multiply quickly and abundantly. In doing so, they break down the sugar into alcohol and carbon dioxide. The gas ensures that the dough of cakes, bread and rolls rises and becomes nice and loose. Yeasts of the genus Saccharomyces cerevisiae, which produce a particularly large amount of carbon dioxide, are usually used for baking. The small organisms also have a lot to offer in terms of nutrients: They are rich in B vitamins and many minerals.

Nothing works conventionally without chemistry

Yeast has been produced industrially in Europe since the 18th century. Initially, it was a by-product of the distilling of schnapps made from fermented grain. It was only when grain became scarce during World War I that the yeast was allowed to grow on molasses, a cheap by-product of the sugar beet industry. Even today, conventional yeast is grown on molasses. Since the sugar-rich syrup also provides a good breeding ground for unwanted bacteria, it must first be cleaned of microorganisms with sulfuric acid and then neutralized with sodium hydroxide solution. However, sugar alone is not enough for yeast to grow. Ammonia compounds, phosphates, sodium carbonate, magnesium sulfate and synthetic vitamins provide the industrial yeast with the necessary nutrients. During their growth, foam is created, which settles on the surface of the nutrient solution and blocks the further production of the yeast cells. Synthetic oils are added to suppress foam formation.

Once the fermentation process is complete, the yeast must be machine washed several times in order to rinse off the additives. Since the nutrients are not completely used up by the cells, considerable quantities of them end up in the wastewater. After each wash, the production plant must also be cleaned and disinfected to prevent contamination. So it is not surprising that the complex wastewater treatment accounts for around 40 percent of the production costs of industrial yeast. 75 kg of ammonia solution, 15 kg of sulfuric acid, 11 kg of phosphoric acid, 4 kg of magnesium sulfate and 10 kg of cleaning and disinfecting agents are the unpleasant residues in the production of a ton of yeast. Converted these figures mean that each yeast cube leaves more than a third of its own weight in poorly degradable substances in the wastewater.

Organic production has the edge

In the production of conventional yeast, auxiliary and growth substances that come from genetically modified microorganisms are likely to be used more and more frequently. It cannot be ruled out that the molasses will also come from genetically modified sugar beets in the future. The use of genetic engineering, the complex production of the yeast and the problematic residues have long been a thorn in the side of organic food manufacturers. And so for several years we have been working hard to offer an ecological alternative. Tests have repeatedly shown that it is possible to grow yeasts on natural raw materials such as sugar beet syrup, Jerusalem artichoke juice, malt extract or drinking whey.

It also works without additives

A Swiss company made the leap from the laboratory to the market at the beginning of the year. Since then, the baker's yeast from the Alpine country has also been produced and marketed in Germany; it will soon also be available in Austria. The organic yeast thrives on a nutrient medium made from wheat flour and wheat germ - naturally from organic farming. In addition, the manufacturer uses lactobacilli. These lactic acid bacteria serve as a natural auxiliary growth substance and should ensure an intense taste and longer shelf life. Organic sunflower oil is used for defoaming.

Since no synthetic auxiliaries have to be rinsed out, the yeast does not have to be washed several times. The production systems only need to be cleaned with steam, which also makes the otherwise common disinfection with sulfuric acid superfluous. This not only saves water, but also protects nature, as the wastewater is free of chemicals. However, the water is so rich in nutrients that it must not be discharged into the sewer system at once. It would stimulate the algae to grow too much. However, if the water levels are correspondingly high, the water from the yeast production may - after consultation with the authorities - drain into the sewer system.

Organic yeast without genetic engineering

The manufacturer of organic yeast guarantees that genetically modified substances are taboo from the first to the last processing step. The selection of raw materials from organic farming is just as consistent. However, the grain is many times more expensive than the waste product molasses. In addition, the overall yield of organic yeast is lower. It is true that enzymes are used that break down the wheat starch and thus make it more available to the yeast. Nevertheless, these special yeast cells grow more slowly and at the same time have a higher demand for raw materials. Compared to the usual dice, the ecological alternative is about three times the price over the counter, i.e. about 80 to 90 pfennigs. For bread rolls that are baked with organic yeast, consumers have to reckon with around two pfennigs more per piece. However, many bakeries do not pass the higher costs for the yeast on to their customers, but instead use other means to intercept them.

Practical test

A number of wholemeal bakers have now tested the grain yeast and report only positive experiences. They confirm that the organic yeast can be used for all wheat baked goods with up to 30 percent rye and is also suitable as a starter culture for rye sourdoughs. They particularly emphasize the spicy taste, the strong aroma, the appetizing scent and the beautiful crumb. In addition, breads baked with organic yeast stay fresh longer because they retain moisture better. The usual pre-dough can be dispensed with; on the other hand, the fermentation process is slower overall and the dough rest takes a little longer. Contrary to the manufacturer's information, however, no more yeast than usual is required. The ecological raising agent is also used in the UGB baking courses. The course instructors were just as satisfied with the successful dough processing and the full-bodied taste of the breads and cakes as the seminar participants. However, be careful when snacking on the raw yeast: It has been shown that it can lead to severe flatulence - probably due to the addition of lactobacilli.

Since May, consumers have been able to buy organic yeast in many health food stores as a 45-gram cube. Yeast flakes made from the new yeast are also on offer. The introduction of further products with organic yeast such as vegetable stock cubes, dry yeast, sprinkling seasoning and yeast extract from the tube is expected to follow in the next few months. The development of the new yeast is also welcomed by the Bundesverband Naturkost Naturwaren. However, there are still no guidelines stipulating their use in organic baked goods. Because the new organic yeast is currently only available in limited quantities, as there is currently only one supplier in Germany. However, it is expected that soon other companies, including the baker's yeast industry, will also bring organic yeast onto the market.

Source: UGB-Forum 5/98, pp. 267-268

▶︎ Newsletter

The UGB newsletter informs you once a month free of charge.
Once a month, the UGB newsletter informs you free of charge about:
current specialist information
• News from science
Book and surf tips
• Recipe of the month
• Seasonal vegetables and fruits
• Job offers in the field of nutrition /
Environment / natural food
• UGB events and new media

▶︎ Trial subscription

Try 3 issues + gift now

Related keywords ...

All articles on yeast ...

This article is taken from the UGB archive.

We would like to point out that the content may have to be re-evaluated due to new scientific findings.