A. Yeast In History
Yeasts can be considered man’s oldest industrial microorganism. It’s likely that man used yeast before the development of a written language. Hieroglyphics suggest that that ancient Egyptians were using yeast and the process of fermentation to produce alcoholic beverages and to leaven bread over 5,000 years ago. The biochemical process of fermentation that is responsible for these actions was not understood and undoubtedly looked upon by early man as a mysterious and even magical phenomenon. t is believed that these early fermentation systems for alcohol production and bread making were formed by natural microbial contaminants of flour, other milled grains and from fruit or other juices containing sugar. Such microbial flora would have included wild yeasts and lactic acid bacteria that are found associated with cultivated grains and fruits. Leaven, referred to in the Bible, was a soft dough-like medium. A small portion of this dough was used to start or leaven each new bread dough. Over the course of time, the use of these starter cultures helped to select for improved yeasts by saving a “good” batch of wine, beer or dough for inoculating the next batch. For hundreds of years, it was traditional for bakers to obtain the yeast to leaven their bread as by-products of brewing and wine making. As a result, these early bakers have also contributed to the selection of these important industrial microorganisms.
It was not until the invention of the microscope followed by the pioneering scientific work of Louis Pasteur in the late 1860’s that yeast was identified as a living organism and the agent responsible for alcoholic fermentation and dough leavening. Shortly following these discoveries, it became possible to isolate yeast in pure culture form. With this new found knowledge that yeast was a living organism and the ability to isolate yeast strains in pure culture form, the stage was setfor commercial production of baker’s yeast that began around the turn of the 20th century. Since that time, bakers, scientists and yeast manufacturers have been working to find and produce pure strains of yeast that meet the exacting and specialized needs of the baking industry.
B. Yeast Today
It was not until the invention of the microscope, followed by the pioneering scientific work of Louis Pasteur in the late 1860’s, that yeast was identified as a living organism and the agent responsible for alcoholic fermentation and dough leavening. Shortly following these discoveries, it became possible to isolate yeast in pure culture form. With the newfound knowledge that yeast was a living organism and the ability to isolate yeast strains in pure culture form, the stage was set for commercial production of baker’s yeast that began around the turn of the 20th century.
Yeast's favourite food is sugar and it loves to eat the sugar in fruit, grains, flour and just about anything. Hence, if you add sugar to yeast when you are proofing it, the bubbles and beige sludge appear more quickly and the bread baking process is faster. For industrial bakers this is good: it gets the product out the door even faster. The same is true for brewing. If you add sugar in your brewing process, the product is ready more quickly (and you get more of it through your factory faster). As a point of interest, there are only four countries in the world that forbid the use of sugar in beer brewing.
BENEFIT OF YEAST
Containing minerals, vitamins and amino acids, yeast offers many benefits.
These indispensable elements for a healthy organism give yeast a crucial role in our diet and balance. For example, yeast and its derivatives are used in food supplements to complement our diet, ensure our well-being and help to improve our health. Yeast is also used in other sectors such as animal foods or cosmetics.
TYPE OF YEAST
Through the selection of strains and development of propagation techniques, more specific applications of yeast are now being found in many different industries, including brewing, malting, farming (animal feeds), pharmaceuticals and dietetics.
The 3 types of yeast that I write below:
- Baker Yeast
Baker’s yeast is the type of yeast used in home and commercial bread baking. It is widely available in a number of forms, including Cake Yeast (also known as Wet, Fresh, or Compressed Yeast), Active Dry Yeast and Instant (or fast-rising) Yeast.
- Nutritional Yeast
Nutritional Yeast is a primary grown pure culture strain of Saccharomyces cerevisiae. It is a powdered yeast without leavening power, marketed for its protein and vitamin content. This type of yeast is available in both powder and pill form. Nutritional Yeast is an excellent source of protein, rich in many of the essential amino acids that complement proteins available from other sources such as corn, wheat, and soy.
- Brewer's Yeast
Brewer’s yeast is a by-product of the brewing industry. After 5-10 succeeding beer fermentations, the yeast, due to increasing contamination, loses its viability and activity and is no longer acceptable for making beer. The yeast then becomes surplus and can be used for the production of food flavors, feed formulations or as nutritional yeast food. Brewer’s Yeast is a dried, inactive yeast that has no fermenting power. It is sold for its nutritional qualities as it is very high in at least 10 separate B-vitamin factors.
source :
www.dakotayeast.com/yeast_history.html
http://www.exploreyeast.com/benefits-yeast
http://redstaryeast.com/science-yeast/story-yeast/
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