Chapter I: Preface

This book has been designed with a view to meet an extensive demand for definite data on the subject of Soured Milks. The author has had this matter brought before him, times without number, by those inquiring for authentic information on the subject, and he has therefore considered it desirable to gather together such information as is available in connection with ancient and modern practice. He has endeavoured to present this to the reader in concise form.

The author is indebted to many friends for their assistance in getting the book together, and would specially mention Dr. H. B. Hutchinson, Bacteriologist, Rothamsted Experimental Station, for assistance in connection with the bacteriology of fermented milks; Mr. Thomas Douglas, of Wimbledon, who has assisted with the chemistry of the subject; Mr. S. Javrilovitch, of Belgrade, Servia, for local information and illustrations; Dr. Otokar Laxa, Bacteriologist, of Prague, Bohemia, for general assistance; the editor of _Bacteriotherapy_, New York, U.S.A., for the use of the group of illustrations 30-44; the publishers of the _Centralblatt für Bakteriologie_, Jena, for the group of illustrations 14-29; and many others, some of whom are referred to in the text.

CONTENTS

CHAPTER PAGE

I.--INTRODUCTORY--HISTORICAL 1

II.--FERMENTED MILKS 15

III.--THE CHEMISTRY OF MILK 47

IV.--HANDLING OF MILK 68

V.--THE BACTERIOLOGY OF FERMENTED OR SOURED MILK 84

VI.--THE PREPARATION OF SOURED MILK IN THE HOUSE 125

VII.--THE PREPARATION OF SOURED MILK IN THE DAIRY 139

VIII.--SOURED MILK IN HEALTH AND DISEASE 151

INDEX 165

ILLUSTRATIONS

FIG. PAGE

THE OLDEST WOMAN IN THE WORLD AND HER SON _Frontispiece_

THE PASS OF BUKOVA 2

KABYLES SOURING MILK 4

THE HANDLING OF MILK IN THE PYRENEES 8

THE CONSTITUENTS OF MILK 48

1.--MICRO-PHOTOGRAPH OF A DROP OF WHOLE MILK 58

2.--MICRO-PHOTOGRAPH OF SEPARATED MILK 58

3.--MICRO-PHOTOGRAPH OF CREAM 58

4.--PHOTOGRAPH OF TWO PETRI DISHES, WHICH HAVE BEEN
INOCULATED WITH ORDINARY MILK 60

5.--THE CREAMOMETER 62

6.--TESTING-GLASS FOR EXTRANEOUS MATTER IN MILK 62

7.--LACTOMETER AND TEST-GLASS 64

8.--PASTEURISER 78

9.--CONTINUOUS APPARATUS FOR THE PRODUCTION OF LARGE
QUANTITIES OF SOURED MILK 82

10.--A MILK-FILLING APPARATUS 90

11.--SECTION THROUGH A KEPHIR GRAIN 94

12.--_Streptococcus lacticus_ (GROTENFELDT) GROWING ON
LACTOSE-AGAR, STAINED BY GRAM'S METHOD 96

13.--PHOTO-MICROGRAPH OF PREPARATION FROM ARMENIAN SOURED
MILK (MATZOON) 106

14.--GRANULE BACILLUS FROM YOGHOURT. SHREDDED PREPARATION
OF A FRESH SKIM-MILK CULTURE 110

15.--GRANULE BACILLUS FROM YOGHOURT, CULTIVATED AFTER
THE USUAL AGAR METHOD 110

16.--GRANULE BACILLUS FROM YOGHOURT. AGAR MILK SUGAR
CULTURE 110

17.--_Bacteria W._ FROM MILK, CULTIVATED TWENTY-FOUR
HOURS 110

18.--AGAR MILK SUGAR CULTURE. FROM THE ORIGINAL BULGARIAN
YOGHOURT 112

19.--AGAR MILK SUGAR CULTURE. SURFACE COLONY OF GRANULE
BACILLUS FROM CALF'S STOMACH 112

20.--AGAR MILK SUGAR CULTURE. DEEP-LYING COLONY
OF GRANULE BACILLUS FROM CALF'S STOMACH 112

21.--AGAR MILK SUGAR. COLONY OF _Bacterium W._ FROM
YOGHOURT 112

22.--TWO COLONIES OF _Bacillus Acidophilus_ FROM CALVES'
MANURE 114

23.--BEER-WORT GELATINE 114

24.--SHREDDED PREPARATION OF BULGARIAN ORIGINAL YOGHOURT 114

25.--GRANULE BACILLUS FROM YOGHOURT. CULTIVATED IN SKIM
MILK IN TWENTY-FOUR HOURS 114

26.--_Bacteria W._, AGAR MILK SUGAR CULTURE 116

27.--_Bacteria acidophilus_ FROM CALVES' MANURE 116

28.--MUCUS FROM CALF'S STOMACH INOCULATED INTO MILK AFTER
EIGHT TRANSFERRINGS 116

29.--DIPLOSTREPTOCOCCUS FROM YOGHOURT. PURE CULTURE IN
SKIM MILK 116

30.--PHOTO-MICROGRAPH OF PREPARATION MADE FROM YOGHOURT,
SHOWING YEAST CELLS 118

31.--PHOTO-MICROGRAPH OF SMEAR FROM GREEK CURDLED MILK
CALLED "GIAOURTI" 118

32.--PHOTO-MICROGRAPH OF SOURED MILK INOCULATED WITH
A TABLET CONTAINING VIABLE AND PURE CULTURES OF
_Bacillus bulgaricus_ 120

33.--PHOTO-MICROGRAPH OF MILK INOCULATED WITH A FERMENT
TABLE IN WHICH _Bacillus bulgaricus_ IS NO LONGER
VIABLE 120

34.--PHOTO-MICROGRAPH OF SMEAR OF CULTURE OF _Bacillus
bulgaricus_ 122

35.--_Bacillus bulgaricus_, SHOWING THE CULTURES
IN ENGLISH COW'S MILK 124

36.--PHOTO-MICROGRAPH OF PURE CULTURE OF _Bacillus
bulgaricus_ 124

37.--PHOTO-MICROGRAPH OF SMEAR OF COMBINED CULTURE
OF _Bacillus bulgaricus_ AND _Bacteria
paralacticus_ 124

38.--PHOTO-MICROGRAPH OF SMEAR OF ONE-MONTH CULTURE
OF _Bacillus bulgaricus_ 126

39.--PHOTO-MICROGRAPH OF CULTURE OF _Bacillus bulgaricus_
IN MALT 126

40.--PHOTO-MICROGRAPH OF SMEAR FROM MILK THAT HAD BEEN
ALLOWED TO SOUR SPONTANEOUSLY 126

41.--PHOTOGRAPH OF AGAR CULTURE, INOCULATED WITH A LACTIC
POWDER 128

42.--PHOTOGRAPH OF TEST-TUBES OF STERILE MILK, INOCULATED
WITH A TABLET PREPARATION SAID TO CONTAIN PURE
CULTURES 128

43.--PHOTOGRAPH OF TEST-TUBES OF STERILE MILK, EACH TUBE
HAVING BEEN INOCULATED WITH A TABLET OF A
PREPARATION SAID TO CONTAIN PURE CULTURES 128

44.--PHOTOGRAPH OF TEST-TUBES OF STERILE MILK INOCULATED
WITH A TABLET OF "LACTOBACILLINE" 130

45.--APPARATUS OF "LE FERMENT" CO. 129

46.--SOURED MILK APPARATUS OF THE MAYA BULGARE COMPANY,
LIMITED 130

47.--LACTIC FERMENTS, LIMITED, APPARATUS 131

48.--MESSRS. ALLEN & HANBURY'S SOURED MILK APPARATUS 132

49.--VIRONELLE APPARATUS FOR SOURING MILK, MADE BY
MESSRS. CLAY, PAGET & COMPANY, LIMITED 132

50.--"LACTOBATOR" MADE BY MESSRS. CHARLES HEARSON & CO.,
LIMITED 140

51.--MESSRS. HEARSON & COMPANY'S "LACTOBATOR" 142

52.--EDGAR'S "LACTOGENERATOR," SOLD BY THE DAIRY SUPPLY
CO., LIMITED 143

53.--APPARATUS OF THE WILLOWS REFRIGERATING CO., LIMITED 144

54.--"LACTO" APPARATUS OF THE DAIRY OUTFIT CO., LIMITED 145

55.--STERILISING APPARATUS FOR STERILISING MILK ON
THE LARGE SCALE 146

56.--ANOTHER METHOD OF STERILISING (DAIRY SUPPLY
CO., LTD.). AN AMERICAN APPARATUS FOR PREPARING
SOURED MILK 148

57.--AN AMERICAN APPARATUS FOR PREPARING SOURED MILK 149

THE BACILLUS OF LONG LIFE