]

[Illustration: BREWING

PLATE II.

FIG. 6.--BURTON-UNION SYSTEM OF CLEANSING. (MESSRS. ALLSOPP'S BREWERY.)

The green beer is filled into the casks, and the excess of yeast, &c., then
works out through the swan necks into the long common gutter shown.]

[v.04 p.0513]

The presence of different types of phosphates in malt, and the important
influence which, according to their nature, they exercise in the brewing
process by way of the enzymes affected by them, have been made the subject
of research mainly by Fernbach and A. Hubert, and by P.E. Petit and G.
Labourasse. The number of enzymes which are now known to take part in the
brewing process is very large. They may with utility be grouped as
follows:--

Name. Role or Nature.
+- Cytase Dissolves cell walls of
| of starch granules.
In the malt ----+- Diastase A Liquefies starch
or mash-tun. +- Diastase B Saccharifies starch.
+- Proteolytic Enzymes -+- (1) Peptic.
| +- (2) Pancreatic.
+- Catalase Splits peroxides.

In fermenting +- Invertase Inverts cane sugar.
wort and -----+- Glucase Splits maltose into glucose.
yeast. +- Zymase Splits sugar into alcohol
and carbonic acid.

BIBLIOGRAPHY.--W.J. Sykes, _Principles and Practice of Brewing_ (London,
1897); Moritz and Morris, _A Text-book of the Science of Brewing_ (London,
1891); H.E. Wright, _A Handy Book for Brewers_ (London, 1897); Frank
Thatcher, _Brewing and Malting_ (London, 1898); Julian L. Baker, _The
Brewing Industry_ (London, 1905); E.J. Lintner, _Grundriss der
Bierbrauerei_ (Berlin, 1904); J.E. Thausing, _Die Theorie und Praxis der
Malzbereitung und Bierfabrikation_ (Leipzig, 1898); E. Michel, _Lehrbuch
der Bierbrauerei_ (Augsburg, 1900); E. Prior, _Chemie u. Physiologie des
Malzes und des Bieres_ (Leipzig, 1896). Technical journals: _The Journal of
the Institute of Brewing_ (London); _The Brewing Trade Review_ (London);
_The Brewers' Journal_ (London); _The Brewers' Journal_ (New York);
_Wochenschrift fuer Brauerei_ (Berlin); _Zeitschrift fuer das gesammte
Brauwesen_ (Munich).

(P. S.)

[1] They were classified at 28 lb in 1896, but since 1897