CHAPTER VII.

NEW PROCESS FOR THE MANUFACTURE OF BEER.

§ I. Preliminary experiments 338

§ II. Method of estimating the oxygen held in solution in wort 353

§ III. On the quantity of oxygen existing in a state of solution in brewers’ worts 364

§ IV. On the combination of oxygen with wort 371

§ V. On the influence of oxygen in combination on the clarification of wort 381

§ VI. Application of the principles of the new process of brewing with the use of limited quantities of air 387

APPENDIX 396

INDEX 403

INDEX TO PLATES.

I. Principal disease-ferments met with in wort and beer 6

II. Appearance under the microscope of the deposit from “turned” beer 20

III. _Torulæ_ in process of development 72

IV. _Mycoderma vini_ functioning as an alcoholic ferment.—Right half, showing appearance of spores just sown; left half, their appearance after an interval of submerged life 116

V. _Mucor_, vegetating submerged, in deficit of air 136

VI. Ferment of _mucor_ 138

VII. Yeast-cells—worn out and dissociated (left), after revival in a sweet wort (right) 148

VIII. Fertile mould-cells from the outer surface of grapes 152

IX. Various examples of the mode of growth of mould-cells from the outer surface of grapes 154

X. One of the ferments of acid fruits at the commencement of fermentation in its natural _medium_ 166

XI. _Saccharomyces pastorianus_, in course of regular growth 168

XII. Ferment-cells from a spontaneous fermentation just starting 184