History of lager brewing
While cold storage of beer, "lagering", in caves for example, was a common practice throughout the medieval period, lager yeast seems to have emerged as a spontaneous mutation or hybridization somewhere in the Holy Roman Empire.[citation needed]
As a new variety of beer, its production faced opposition from established brewers. Private brewers of lager were often required to produce their beer outside city walls; more traditional brewers produced beer which evolved into the Altbier and Kölsch styles.
While lagers have become the predominant form of beer in America, it was not until 1840 that they made their way to America. With the influx of German immigrants during the 19th century, it was only a matter of time until bottom-fermenting beers would be produced there. Lagering may have had its roots in Germany but it was John Wagner with his small brewery on St. John Street near Poplar, Philadelphia, who started the first lager-producing brewery in America using yeast strains which he brought with him from Bavaria, where he had been a brewmaster.
In 1953, New Zealander Morton W. Coutts developed a process known as continuous fermentation. Continuous fermentation allowed the production of lager at a much faster pace, albeit with a reduction in flavor development. This development made possible the mass production of lager beer at a rate competitive with ales. As this technology became widespread, the light lager style emerged, quickly becoming the most popular style of beer in much of the industrialized world.
Since 1950, pale lager has displaced ale as the type of beer most consumed in the United Kingdom, and also constitutes the overwhelming majority of beer produced and sold in the United States, China, Australia, India, Japan, France, Italy, Russia and most countries where beer is made and consumed.
Resource: http://en.wikipedia.org/wiki/Lager
Monday, September 27, 2010
How do Yeast Budding?
Budding Yeast: Saccharomyces cerevisiae
Saccharomyces cerevisiae, the budding yeast, is the common yeast used in baking ("baker's yeast") and brewing ("brewer's yeast"). (It is only distantly related to another unicellular fungus, Schizosaccharomyces pombe, the fission yeast.)
It is a popular "model" organism in the laboratory because it is a unicellular eukaryote whose cellular activities are much more like ours than a bacterium like E. coli. But like E. coli,
It can be cultured easily.
It grows rapidly.
Its entire genome is known. [Link]
It can be easily transformed with genes from other sources.
Life Cycle
Budding yeast can live with either two genomes (diploid) or one (haploid). In either case, it reproduces by forming buds (hence the name) by mitosis.
Haploid cells occur in two different mating types: a or α. The type is determined by the expression of a gene at an active mating type locus.
Haploid cells can live indefinitely in the haploid condition. However, if two cells of opposite mating types meet, they can fuse and enter the diploid phase of the cell cycle.
This is not as rare event as you might expect.
Germination of the haploid spores takes place while they are still within the ascus and mating normally occurs there.
Even if haploid cells go through a period of growth, they can still find cells of the opposite mating type most of the time. Although the illustration shows each haploid cell producing a bud of the same mating type, often the cell switches mating type. It is able to do so because in addition to the active mating type locus, it contains two "silent" loci - one a and one α. A double-strand break (DSB) at the active locus is repaired with the information from one of the silent loci. If the cell is a, it prefers to tap the information in the silent α locus; and vice-versa.
Cells in the diploid phase are more resistant to harsh environmental conditions. When diploid cells begin to run out of food, they undergo meiosis, forming four haploid spores in an ascus (Saccharomyces cerevisiae belongs to the ascomycetes.)
When good conditions return, the spores germinate producing four haploid yeast cells: two a and two α.
Resource : http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/Y/Yeast.html
Saccharomyces cerevisiae, the budding yeast, is the common yeast used in baking ("baker's yeast") and brewing ("brewer's yeast"). (It is only distantly related to another unicellular fungus, Schizosaccharomyces pombe, the fission yeast.)
It is a popular "model" organism in the laboratory because it is a unicellular eukaryote whose cellular activities are much more like ours than a bacterium like E. coli. But like E. coli,
It can be cultured easily.
It grows rapidly.
Its entire genome is known. [Link]
It can be easily transformed with genes from other sources.
Life Cycle
Budding yeast can live with either two genomes (diploid) or one (haploid). In either case, it reproduces by forming buds (hence the name) by mitosis.
Haploid cells occur in two different mating types: a or α. The type is determined by the expression of a gene at an active mating type locus.
Haploid cells can live indefinitely in the haploid condition. However, if two cells of opposite mating types meet, they can fuse and enter the diploid phase of the cell cycle.
This is not as rare event as you might expect.
Germination of the haploid spores takes place while they are still within the ascus and mating normally occurs there.
Even if haploid cells go through a period of growth, they can still find cells of the opposite mating type most of the time. Although the illustration shows each haploid cell producing a bud of the same mating type, often the cell switches mating type. It is able to do so because in addition to the active mating type locus, it contains two "silent" loci - one a and one α. A double-strand break (DSB) at the active locus is repaired with the information from one of the silent loci. If the cell is a, it prefers to tap the information in the silent α locus; and vice-versa.
Cells in the diploid phase are more resistant to harsh environmental conditions. When diploid cells begin to run out of food, they undergo meiosis, forming four haploid spores in an ascus (Saccharomyces cerevisiae belongs to the ascomycetes.)
When good conditions return, the spores germinate producing four haploid yeast cells: two a and two α.
Resource : http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/Y/Yeast.html
Some Recomendation about Yest Books
1. Is Candida Yeast Ruining Your Good Health?
Have you been told your health problems are all in your head? Do you suffer from low energy, depression, digestive problems, and/or excessive skin irritation? If so, you may have an overgrowth of a common yeast, Candida albicans. Fueled by everything from diet to medication to environmental factors, this hidden epidemic affects as many as 90 percent of Americans and Canadians—men, women, and children alike.
Now there are effective alternatives to your suffering. This eye-opening guide will help you conquer Candida and achieve optimal mental, physical, and emotional health. Inside, you will discover:
•Holistic, natural, herbal, and vitamin supplements that combat Candida Yeast
•Innovative tips for improving your lifestyle and maintaining a healthy mind and body
•Wholesome diet and menu options that taste delicious
•New medical and nutritional guidelines for asthma, cancer, diabetes, and more
2. The Bible Cure For Candida & Yeast Infections (Bible Cure Series) [Paperback]
People who suffer from fatigue, muscle aches, food sensitivities, psoriasis, asthma and many other common complaints may actually have a yeast infection. Too much yeast (specifically, "Candida Albicans") in the body is a problem that applies equally to both men and women. Candida Albican, a common yeast, normally lives in the human body where it causes no problems-provided the body's biochemistry is balanced and the immune system is strong. Dr. Don Colbert shares his insight on yeast infections and suggests cures to prevent them from weakening the immune system.
About the Author
Don Colbert, M.D. is board certified in family practice and specializes in alternative therapies. He has his own practice in the Orlando, Florida area and has helped thousands of people discover the joy of walking in divine health.
He now has 18 titles of "Bible Cure" booklets with over 500,000 copies in print.
3. Methods in Yeast Genetics: A Cold Spring Harbor Laboratory Course Manual, 2005 Edition [Paperback]
This update of the 2000 edition is the latest version of a book that remains the best single source of basic genetics techniques for Saccharomyces cerevisiae... Based on the long running course at Cold Spring Harbor, it contains a mixture of experiments, techniques, protocols and basic data. The experiments include very clear explanations of the logic behind the approaches. New techniques like TAP tagging are included and many familiar experiments have been revised to take into account, for example, cytological advances with better fluorophores and GFP-fusions, and the ready availability of systematic deletion strains. It is an essential purchase for all laboratories. Microbiology Today --Cold Spring Harbor
Product Description
Methods in Yeast Genetics is a course that has been offered annually at Cold Spring Harbor Laboratory for the last thirty years. This is an updated edition of the course manual, which provides a set of teaching experiments, along with protocols and recipes for the standard techniques and reagents used in the study of yeast biology. Since the last edition of the manual was published (2000), revolutionary advances in genomics and proteomics technologies have had a significant impact on the field. This updated edition reflects these advances, and also includes new techniques involving vital staining, visualization of Green Fluorescent Protein, new drug resistance markers, high-copy suppression, Tandem Affinity Protein tag protein purification, gene disruption by double-fusion polymerase chain reaction, and many other recent developments.
4. Brewing Yeast and Fermentation [Paperback]
Now Available for the First Time in Paperback!
This unique volume provides a definitive overview of modern and traditional brewing fermentation. Written by two experts with unrivalled experience from years with a leading international brewer, coverage includes all aspects of brewing fermentation together with the biochemistry, physiology and genetics of brewers' yeast. Brewing Yeast and Fermentation is unique in that brewing fermentation and yeast biotechnology are covered in detail from a commercial perspective.
Now available for the first time in paperback, the book is aimed at commercial brewers and their ingredient and equipment suppliers (including packaging manufacturers). It is also an essential reference source for students on brewing courses and workers in research and academic institutions.
Definitive reference work and practical guide for the industry.
Highly commercially relevant yet academically rigorous.
Authors from industry leading brewers.
Have you been told your health problems are all in your head? Do you suffer from low energy, depression, digestive problems, and/or excessive skin irritation? If so, you may have an overgrowth of a common yeast, Candida albicans. Fueled by everything from diet to medication to environmental factors, this hidden epidemic affects as many as 90 percent of Americans and Canadians—men, women, and children alike.
Now there are effective alternatives to your suffering. This eye-opening guide will help you conquer Candida and achieve optimal mental, physical, and emotional health. Inside, you will discover:
•Holistic, natural, herbal, and vitamin supplements that combat Candida Yeast
•Innovative tips for improving your lifestyle and maintaining a healthy mind and body
•Wholesome diet and menu options that taste delicious
•New medical and nutritional guidelines for asthma, cancer, diabetes, and more
2. The Bible Cure For Candida & Yeast Infections (Bible Cure Series) [Paperback]
People who suffer from fatigue, muscle aches, food sensitivities, psoriasis, asthma and many other common complaints may actually have a yeast infection. Too much yeast (specifically, "Candida Albicans") in the body is a problem that applies equally to both men and women. Candida Albican, a common yeast, normally lives in the human body where it causes no problems-provided the body's biochemistry is balanced and the immune system is strong. Dr. Don Colbert shares his insight on yeast infections and suggests cures to prevent them from weakening the immune system.
About the Author
Don Colbert, M.D. is board certified in family practice and specializes in alternative therapies. He has his own practice in the Orlando, Florida area and has helped thousands of people discover the joy of walking in divine health.
He now has 18 titles of "Bible Cure" booklets with over 500,000 copies in print.
3. Methods in Yeast Genetics: A Cold Spring Harbor Laboratory Course Manual, 2005 Edition [Paperback]
This update of the 2000 edition is the latest version of a book that remains the best single source of basic genetics techniques for Saccharomyces cerevisiae... Based on the long running course at Cold Spring Harbor, it contains a mixture of experiments, techniques, protocols and basic data. The experiments include very clear explanations of the logic behind the approaches. New techniques like TAP tagging are included and many familiar experiments have been revised to take into account, for example, cytological advances with better fluorophores and GFP-fusions, and the ready availability of systematic deletion strains. It is an essential purchase for all laboratories. Microbiology Today --Cold Spring Harbor
Product Description
Methods in Yeast Genetics is a course that has been offered annually at Cold Spring Harbor Laboratory for the last thirty years. This is an updated edition of the course manual, which provides a set of teaching experiments, along with protocols and recipes for the standard techniques and reagents used in the study of yeast biology. Since the last edition of the manual was published (2000), revolutionary advances in genomics and proteomics technologies have had a significant impact on the field. This updated edition reflects these advances, and also includes new techniques involving vital staining, visualization of Green Fluorescent Protein, new drug resistance markers, high-copy suppression, Tandem Affinity Protein tag protein purification, gene disruption by double-fusion polymerase chain reaction, and many other recent developments.
4. Brewing Yeast and Fermentation [Paperback]
Now Available for the First Time in Paperback!
This unique volume provides a definitive overview of modern and traditional brewing fermentation. Written by two experts with unrivalled experience from years with a leading international brewer, coverage includes all aspects of brewing fermentation together with the biochemistry, physiology and genetics of brewers' yeast. Brewing Yeast and Fermentation is unique in that brewing fermentation and yeast biotechnology are covered in detail from a commercial perspective.
Now available for the first time in paperback, the book is aimed at commercial brewers and their ingredient and equipment suppliers (including packaging manufacturers). It is also an essential reference source for students on brewing courses and workers in research and academic institutions.
Definitive reference work and practical guide for the industry.
Highly commercially relevant yet academically rigorous.
Authors from industry leading brewers.
Learn about how yeast growth & yeast nutrition
Growth and nutrition
Yeasts are chemoorganotrophs as they use organic compounds as a source of energy and do not require sunlight to grow. Carbon is obtained mostly from hexose sugars such as glucose and fructose, or disaccharides such as sucrose and maltose. Some species can metabolize pentose sugars like ribose,alcohols, and organic acids. Yeast species either require oxygen for aerobic cellular respiration (obligate aerobes), or are anaerobic but also have aerobic methods of energy production (facultative anaerobes). Unlike bacteria, there are no known yeast species that grow only anaerobically (obligate anaerobes). Yeasts grow best in a neutral or slightly acidic pH environment.
Yeasts vary in what temperature range they grow best. For example, Leucosporidium frigidum grows at -2 to 20 °C (28 to 68 °F), Saccharomyces telluris at 5 to 35 °C (41 to 95 °F) and Candida slooffi at 28 to 45 °C (82 to 113 °F).The cells can survive freezing under certain conditions, with viability decreasing over time.
Yeasts are generally grown in the laboratory on solid growth media or in liquid broths. Common media used for the cultivation of yeasts include potato dextrose agar (PDA) or potato dextrose broth, Wallerstein Laboratories nutrient (WLN) agar, yeast peptone dextrose agar (YPD), and yeast mould agar or broth (YM). Home brewers who cultivate yeast frequently use dried malt extract (DME) and agar as a solid growth medium. The antibiotic cycloheximide is sometimes added to yeast growth media to inhibit the growth of Saccharomyces yeasts and select for wild/indigenous yeast species. This will change the yeast process.
The appearance of a white thready yeast commonly known as kahm yeast is often a byproduct of the lactofermentation (or pickling) of certain vegetables, usually the result of exposure to air. Although harmless it can give pickled vegetables a bad flavour and so must be removed regularly during fermentation.
Resource: http://en.wikipedia.org/wiki/Yeast
Yeasts are chemoorganotrophs as they use organic compounds as a source of energy and do not require sunlight to grow. Carbon is obtained mostly from hexose sugars such as glucose and fructose, or disaccharides such as sucrose and maltose. Some species can metabolize pentose sugars like ribose,alcohols, and organic acids. Yeast species either require oxygen for aerobic cellular respiration (obligate aerobes), or are anaerobic but also have aerobic methods of energy production (facultative anaerobes). Unlike bacteria, there are no known yeast species that grow only anaerobically (obligate anaerobes). Yeasts grow best in a neutral or slightly acidic pH environment.
Yeasts vary in what temperature range they grow best. For example, Leucosporidium frigidum grows at -2 to 20 °C (28 to 68 °F), Saccharomyces telluris at 5 to 35 °C (41 to 95 °F) and Candida slooffi at 28 to 45 °C (82 to 113 °F).The cells can survive freezing under certain conditions, with viability decreasing over time.
Yeasts are generally grown in the laboratory on solid growth media or in liquid broths. Common media used for the cultivation of yeasts include potato dextrose agar (PDA) or potato dextrose broth, Wallerstein Laboratories nutrient (WLN) agar, yeast peptone dextrose agar (YPD), and yeast mould agar or broth (YM). Home brewers who cultivate yeast frequently use dried malt extract (DME) and agar as a solid growth medium. The antibiotic cycloheximide is sometimes added to yeast growth media to inhibit the growth of Saccharomyces yeasts and select for wild/indigenous yeast species. This will change the yeast process.
The appearance of a white thready yeast commonly known as kahm yeast is often a byproduct of the lactofermentation (or pickling) of certain vegetables, usually the result of exposure to air. Although harmless it can give pickled vegetables a bad flavour and so must be removed regularly during fermentation.
Resource: http://en.wikipedia.org/wiki/Yeast
Yeast History
History of the Yeast Cell:
The word "yeast" comes to us from Old English gist, gyst, and from the Indo-European root yes-, meaning boil, foam, or bubble. Yeast microbes are probably one of the earliest domesticated organisms. People have used yeast for fermentation and baking throughout history. Archaeologists digging in Egyptian ruins found early grinding stones and baking chambers for yeasted bread, as well as drawings of 4,000-year-old bakeries and breweries.In 1680 the Dutch naturalist Anton van Leeuwenhoek first microscopically observed yeast, but at the time did not consider them to be living organisms, but rather globular structures.In 1857 French microbiologist Louis Pasteur proved in the paper "Mémoire sur la fermentation alcoolique" that alcoholic fermentation was conducted by living yeasts and not by a chemical catalyst.Pasteur showed that by bubbling oxygen into the yeast broth, cell growth could be increased, but the fermentation inhibited – an observation later called the Pasteur effect.
By the late 18th century, two yeast strains used in brewing had been identified: Saccharomyces cerevisiae, so called "high" or top yeast, and S. carlsbergensis, "low" or bottom yeast. High yeast was sold commercially by the Dutch for bread making starting in 1780, while around 1800, the Germans started producing S. cerevisiae in the form of cream. In 1825 a method was developed to remove the liquid so the yeast could be prepared as solid blocks.The industrial production of yeast blocks was enhanced by the introduction of the filter press in 1867. In 1872, Baron Max de Springer developed a manufacturing process to create granulated yeast, a technique that was used until the first World War. In the United States, naturally occurring airborne yeasts were used almost exclusively until commercial yeast was marketed at the Centennial Exposition in 1876 in Philadelphia, where Charles L. Fleischmann exhibited the product and a process to use it, as well as serving the resultant baked bread.
Resource: http://en.wikipedia.org/wiki/Yeast
The word "yeast" comes to us from Old English gist, gyst, and from the Indo-European root yes-, meaning boil, foam, or bubble. Yeast microbes are probably one of the earliest domesticated organisms. People have used yeast for fermentation and baking throughout history. Archaeologists digging in Egyptian ruins found early grinding stones and baking chambers for yeasted bread, as well as drawings of 4,000-year-old bakeries and breweries.In 1680 the Dutch naturalist Anton van Leeuwenhoek first microscopically observed yeast, but at the time did not consider them to be living organisms, but rather globular structures.In 1857 French microbiologist Louis Pasteur proved in the paper "Mémoire sur la fermentation alcoolique" that alcoholic fermentation was conducted by living yeasts and not by a chemical catalyst.Pasteur showed that by bubbling oxygen into the yeast broth, cell growth could be increased, but the fermentation inhibited – an observation later called the Pasteur effect.
By the late 18th century, two yeast strains used in brewing had been identified: Saccharomyces cerevisiae, so called "high" or top yeast, and S. carlsbergensis, "low" or bottom yeast. High yeast was sold commercially by the Dutch for bread making starting in 1780, while around 1800, the Germans started producing S. cerevisiae in the form of cream. In 1825 a method was developed to remove the liquid so the yeast could be prepared as solid blocks.The industrial production of yeast blocks was enhanced by the introduction of the filter press in 1867. In 1872, Baron Max de Springer developed a manufacturing process to create granulated yeast, a technique that was used until the first World War. In the United States, naturally occurring airborne yeasts were used almost exclusively until commercial yeast was marketed at the Centennial Exposition in 1876 in Philadelphia, where Charles L. Fleischmann exhibited the product and a process to use it, as well as serving the resultant baked bread.
Resource: http://en.wikipedia.org/wiki/Yeast
What Is Yeast
Yeasts are single-celled fungi. As fungi, they are related to the other fungi that people are more familiar with. These include edible mushrooms available at the supermarket, common baker’s yeast used to leaven bread, molds that ripen blue cheese and the molds that produce antibiotics for medical and veterinary use. Many consider edible yeast and fungi to be as natural as fruits and vegetables.
Yeast Cells
Over 600 different species of yeast are known and they are widely distributed in nature. They are found in association with other microorganisms as part of the normal inhabitants of soil, vegetation, marine and other aqueous environments. Some yeast species are also natural inhabitants of man and animals. While some species are highly specialized and found only in certain habitats at certain times of the year, other species are generalists and can be isolated from many different sources.
Baker’s yeast is used to leaven bread throughout the world and it is the type of yeast that people are most familiar with. Baker’s yeast is produced from the genus and species of yeast called Saccharomyces cerevisiae. The scientific name of the genus of baker’s yeast, Saccharomyces, refers to “saccharo” meaning sugar and “myces” meaning fungus. The species name, cerevisiae, is derived from the name Ceres, the Roman goddess of agriculture. Baker’s yeast products are made from strains of this yeast selected for their special qualities relating to the needs of the baking industry.
The typical yeast cell is approximately equal in size to a human red blood cell and is spherical to ellipsoidal in shape. Because of its small size, it takes about 30 billion yeast cells to make up to one gram of compressed baker’s yeast. Yeast reproduce vegetatively by budding, a process during which a new bud grows from the side of the existing cell wall. This bud eventually breaks away from the mother cell to form a separate daughter cell. Each yeast cell, on average, undergoes this budding process 12 to 15 times before it is no longer capable of reproducing. During commercial production, yeast is grown under carefully controlled conditions on a sugar containing media typically composed of beet and cane molasses. Under ideal growth conditions a yeast cell reproduces every two to three hours.
Yeast is the essential ingredient in many bakery products. It is responsible for leavening the dough and imparting a delicious yeast fermentation flavor to the product. It is used in rather small amounts in most bakery products, but having good yeast and using the yeast properly often makes the difference between success and something less than success in a bakery operation.
Resource : www.dakotayeast.com/yeast_what.html
Yeast Cells
Over 600 different species of yeast are known and they are widely distributed in nature. They are found in association with other microorganisms as part of the normal inhabitants of soil, vegetation, marine and other aqueous environments. Some yeast species are also natural inhabitants of man and animals. While some species are highly specialized and found only in certain habitats at certain times of the year, other species are generalists and can be isolated from many different sources.
Baker’s yeast is used to leaven bread throughout the world and it is the type of yeast that people are most familiar with. Baker’s yeast is produced from the genus and species of yeast called Saccharomyces cerevisiae. The scientific name of the genus of baker’s yeast, Saccharomyces, refers to “saccharo” meaning sugar and “myces” meaning fungus. The species name, cerevisiae, is derived from the name Ceres, the Roman goddess of agriculture. Baker’s yeast products are made from strains of this yeast selected for their special qualities relating to the needs of the baking industry.
The typical yeast cell is approximately equal in size to a human red blood cell and is spherical to ellipsoidal in shape. Because of its small size, it takes about 30 billion yeast cells to make up to one gram of compressed baker’s yeast. Yeast reproduce vegetatively by budding, a process during which a new bud grows from the side of the existing cell wall. This bud eventually breaks away from the mother cell to form a separate daughter cell. Each yeast cell, on average, undergoes this budding process 12 to 15 times before it is no longer capable of reproducing. During commercial production, yeast is grown under carefully controlled conditions on a sugar containing media typically composed of beet and cane molasses. Under ideal growth conditions a yeast cell reproduces every two to three hours.
Yeast is the essential ingredient in many bakery products. It is responsible for leavening the dough and imparting a delicious yeast fermentation flavor to the product. It is used in rather small amounts in most bakery products, but having good yeast and using the yeast properly often makes the difference between success and something less than success in a bakery operation.
Resource : www.dakotayeast.com/yeast_what.html
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