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Practical Studies in Fermentation
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Publisher: E. & F. N. Spon, London & New York, 1896.
Hard Cover, 277 pages, 6x9.
Item #1500
Many historians give Louis Pasteur and his Études sur la Bière the lion's share of credit for cracking the mysteries of fermentation in brewing. In reality, it was Pasteur's friend and colleague, Emil Christian Hansen, whose research made a far greater impact on beer making. In this book, Hansen chronicles his career-long research into yeast and fermentation at the Carlsberg Laboratory in Denmark. In his own words, Hansen relays the complete story of how his studies in single-cell yeast culture developed and became a canon of brewing worldwide. He gives details not only of the scientific nature of his findings, but also of the many battles he fought to convince his colleagues in both the scientific and brewing communities of the value of his research. The initial resistance he encountered stemmed partly from the fact that Hansen had contradicted certain aspects of Pasteur's well-regarded research (though Pasteur himself applauded Hansen's discoveries). The book is a rare first-person account of one of the truly groundbreaking advances in brewing science. There are about 20 handsome period advertisements in the front and rear of the book for all sorts of brewing industry equipment, ingredients, supplies and services. CHAPTER I. PURE CULTURES OF SYSTEMATICALLY SELECTED YEASTS IN THE FERMENTATION INDUSTRIES 1. WHEREIN THE NEW ADVANCE CONSISTS I - Pitching yeast before and after introduction of the reform
- Three periods of conflict
2. MY METHODS OF PURE CULTIVATION - My first pure cultures were prepared by dilution method in liquid medium
- Koch's plate culture in nutrient gelatine
- My single-cell culture in moist chamber
- Brefeld's methods
- The methods of pure culture are only technical expedients
3. THE CONTRIBUTIONS OF PREVIOUS INVESTIGATORS - The new science of the organisms of fermentation was founded by Pasteur's Etudes sur la Bier
- Cagniard Latour, Schwann, Turpin and Kutzing
- The reasons why Pasteur's method for the purification of yeast by means of tartaric acid found no application in practice
- Different views concerning yeast
4. THE PRACTICAL RESULTS WHICH HAVE BEEN ACHIEVED - Jacobsen's objections
- The "diseases" produed by alcoholic ferments in the Tuborg and Old Carlsberg Breweries
- My first experiments with pure cultivated yeast in Old Carlsberg
- Are special secondary yeasts necessary to bring about the desired fermentation?
- Scientists who from the beginning have worked for my reform
- The advantages of the reform
- Misunderstandings and mistakes
- Reasons for advising against the employment of mixed yeasts
- The question of abolishing the open coolers could only be considered after the yeast question had been solved
5. THE PREPARATION OF PURE-CULTIVATED YEASTS ON A LARGE SCALE - Preliminary work
- The sample to be tested for wild yeast is best taken at the end of the primary fermentation, and the sample to be used in the preparation of the desired pure culture of the brewery yeast is best taken at the commencement of the primary fermentation
- Temporary variation
- Duration of vitality of yeast cells in wort, cane sugar solution and in filter paper
- Experience shows that a solution of cane sugar affords a good medium for the preservation of yeasts at the ordinary room-temperature
- My Old Method
- The sterilisation of wort in glass and metal vessels
- The thorough aeration of the wort is of especial importance
- Manipulations with pure yeast in the fermenting cellar
- The Pure Yeast Apparatus
- Description of the separate parts and instructions for the employment
- of the apparatus devised by Kiihle and myself
- Various modifications of the apparatus for low fermentation
- For high fermentation
- Cost of the apparatus
- Fillers
- Chamberland's porcelain filters
- Schroder and Dusch's cotton-wool niters
- The niters of the pure yeast apparatus
- Their efficiency
- The Introduction of the Yeast into the Propagating Apparatus and its Transport
- How the yeast is introduced into the apparatus
- Laboratories in which my methods are carried out
- Course for students in Carlsberg laboratory
- Methods for transmitting pure cultivated yeasts
CHAPTER II. RESEARCHES ON YEASTS I. CHARACTERISTICS OF THE SACCHAROMYCETES - Development and germination of spores; film-formation; form of the cells under certain conditions of cultivation; behaviour with regard to the carbohydrates
- Difference between the spore contents of the culture yeasts as compared with the wild yeasts
- Recent investigations on the origin of the Saccharomycetes
2. HIGH AND LOW YEASTS - Pasteur's and Reess's views
- My experiments undertaken since 1884
3. INVESTIGATIONS ON LOW-FERMENTATION YEASTS WHICH HAVE BEEN TESTED IN PRACTICE - The names Stuck, cerrvisia, Sacch. ellipsoideus, &c., do not represent single fixed species but groups of species and varieties
- The Carlsberg bottom yeasts Nos. I and 2
4. ON VARIATION - Transformations of a temporary nature
- Transformations which under the most varied conditions of culture are permanent, and transmitted from generation to generation
5. MAIN RESULT
CHAPTER III. THE PRACTICAL EXAMINATION OF BEER IN THE STORAGE CASKS WITH REFERENCE TO ITS STABILITY. CHAPTER IV. THE TECHNICAL ANALYSIS OF AIR AND WATER FOR MICRO-ORGANISMS. 1. THE PRACTICAL RESULTS OF MY AIR ANALYSES 2. THE PRINCIPLES OF ZYMOTECHNIC WATER ANALYSES - The only use of the hygienic method in the brewery is for testing Comparison of the results obtained by Koch's gelatin plate method with those obtained by my flask method
- Wort bacteria and the common water bacteria
- Description of my method
- Its employment in the brewery
CHAPTER V. WHAT IS THE PURE YEAST OF PASTEUR? 1. The old method which I made use of in 1880 for the preparation of my pure cultures of Sacch. apiculatus - Duclaux's statement as to the efficiency of Pasteur's method of pure culture
- Theoretical objections raised by Miquel, Jorgensen, Denamur and myself
- Duclaux's lectures at the Brewers' Congresses at Paris and Lille in 1889 and 1890
- Velten's attacks against my method of pure culture
- His statement that Pasteur's method is the right one for purifying brewers' yeast
- The experiments of Messrs. Jacobsen at Old and New Carlsbeif
2. Pasteur's method of pure culture is tested - The first four experiments
- Results
- The fifth and sixth experiments were specially carried out in order to test Velten's statements
- In Pasteur's method, as recommended by Velten and Duclaux, there is no certainty of obtaining a pure culture, and with regard to brewery yeast it even brings about a suppression of the desired "culture" yeast, whilst the disease yeasts present are even caused to develop more strongly
- New objections raised by Velten in 1891
- Jorgensen's investigations
- The new objections are disproved by the seventh and eighth experiments
3. The objections to the employment of tartaric acid apply also to hydrofluoric acid and other antiseptics - Cultivation in a nutrient solution containing tartaric acid in the analysis of yeast
4. What Pasteur meant by a pure brewery yeast - Pasteur's work and my work rest upon two quite different standpoints
CHAPTER VI. INVESTIGATIONS ON THE "DISEASES" OF BEER, PRODUCED BY ALCOHOLIC FERMENTS. CHAPTER VII. ON THE PRESENT POSITION OF MY SYSTEM OF PURE YEAST CULTURE. 1. THE OBJECT OF THIS REVIEW 2. LOW-FERMENTATION BREWERIES 3. HIGH FERMENTATION BREWERIES 4. DISTILLERIES AND YEAST FACTORIES 5. WINE, CIDER AND FRUIT-JUICE FERMENTATIONS 6. RETROSPECT AND CONCLUDING REMARKS
INDEX
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