Skip to main content
BFI logo











Screenonline banner
Brewster's Magic (1933)


Main image of Brewster's Magic (1933)
For Secrets of Nature
35mm, black and white, 8 mins
Production CompanyBritish Instructional Films

A study of hops, barley and yeast, and how they interact.

Show full synopsis

Commencing with a sprightly setting of 'There's a Tavern in the Town' by W.E. Hodgson, conductor of the orchestra at the Marble Arch Pavilion cinema in Oxford Street, Brewster's Magic is anxious to establish its credentials as a film on a popular topic. The producers of the Secrets of Nature series (1922-33) had discovered that the public response was much more enthusiastic to familiar subjects plainly shot, such as the aphids that plagued rose growers, than it was to technically virtuoso feats such as their film on the parasitic plant, dodder. The upbeat populism of this film, however, scarcely conceals the fact that this Secret, ostensibly about beer, is essentially a didactic film on its three main constituents: hops, malted barley and yeast.

These three subjects, interspersed with relevant actuality footage, provide a showcase for the technical expertise of Percy Smith. The growth of the hop plant, with its close-up detail, demonstrates his mastery of time-lapse cinematography. This is one of the occasions where the commentary alludes to the technique, explaining, for instance, that the 'lovely movement' of the leaves has been speeded-up 25,000 times. Patient time-lapse, in combination with the commentary, explains the reason for growing only female hop flowers. A brief actuality sequence shows hop pickers at work. In the barley-malting sequence, Smith's time-lapse skills are put to unusual use, showing the swelling of barley grains, their sprouting of roots, and withering after the removal of the water supply. An animated sequence of a cross section of the grain shows off further confident technique; an animated pointer, with which the commentary is synchronised, reveals the maltster's reason for killing off the grains, so that the enzyme can continue to convert starch into sugar, to produce malt.

A new actuality sequence shows brewers moving barrels, as a prelude to the final third, in which Smith's microcinematography is put to work to explain the action of yeast. A sequence very rare among the Secrets films follows; an animated chemical equation shows how the yeast-malt-hop mixture produces alcohol and carbon dioxide; normally the films avoid being this directly didactic. The film is rounded-off with a final actuality shot of a man in a flat cap consuming the beer from a tankard, accompanied by Hodgson's rendition of 'Bless 'em all', as if the film has suddenly remembered that it's an amusing lightweight film and not a chemistry lesson after all.

Timothy Boon

Dr Timothy Boon is Senior Curator of the Science Museum

Click titles to see or read more

Video Clips
1. Growing hops (2:52)
Cheer Boys Cheer (1939)
Secrets of Nature (1922-33)