Problems in Burton
Murphy’s diversion was not followed up and instead Hansen himself returned to the fray in support of the views expressed by Jorgensen. In a letter to the Journal of the Federated Institutes of Brewing published in January 1900, characteristically peppered with references to ‘my pure cultivation system’- Hansen was very possessive of his achievements - he rehearsed the arguments and evidence in favor of pure yeast from both continental and British sources. He blamed the lack of penetration of his system in British breweries to the ‘secretiveness’ of the brewers and called for a more open publication of results rather than opinions. Stimulated by Hansen’s challenge George Harris Morris immediately responded with a detailed paper read to the (London) Institute of Brewing in May 1900. At this time Morris was consulting chemist to the Country Brewers’ Society and lecturer in technical bacteriology in the Jenner (now Lister) Institute. But between 1883 and 1894 he had been Horace Brown’s assistant at Worthingtons in Burton-on-Trent. His paper recounted his experiences with pure yeast during that period. Morris had been sent by Brown to Copenhagen in 1885 Brewery History Number 149 31 to learn about pure yeast culture directly from Hansen. On his return to Burton, he set about employing the new techniques with vigor using a Hansen-Kuhle yeast culture apparatus installed at Worthingtons. Both he and Horace Brown were convinced that the future lay in ‘Hansen’ s beautiful system’. Morris describes in detail the extensive measures taken to guard against contamination during yeast propagation and in subsequent fermentations. Fermentations with the pure culture were carried out side by side with regular fermentations with the normal brewery yeast. The course of fermentation of both trials and controls was said to be ‘identical’. Differences came when the beers were run into cask (or bottle) for conditioning. The pure yeast beers did not condition, or when they did so were always found to be contaminated with wild yeast. Morris met with failure with both ‘stock ales’ which received prolonged (six months plus) conditioning and ‘running ales’ which were ‘brewed, racked and drunk all in the course of one month’. The beers tasted clean but remained thin and flat unless as Morris puts it ‘cold malt-extract or ordinary sugar priming’ were added. In nine years of experimentation in which he brewed over 2,000 barrels of beer using a variety of different isolates from the brewery culture, Morris could never obtain the same results with pure culture as he could with his ‘ordinary’ yeast.
Morris did not deny that pure culture worked well in bottom fermentation breweries and also in continental top fermentation breweries (he had been to Holland and Belgium to see for himself in 1890), but it did not work for any of Worthington’s beers. He attributed this discrepancy to differences in attenuation between continental beers and those made in Burton. In his own words In the case of the majority of English beers, the amount of matter left unfermented is not considerable, and I doubt very much whether, in any but the quickest running ales, this readily fermentable matter is sufficient to provide the after fermentation which we find is necessary.
It is evident from the subsequent discussion that the audience was convinced both by the meticulous nature of Morris’s experiments and by his explanations of his results. They would all have known that a particular characteristic of beers produced in the Burton Union system was their high degree of attenuation. But if Morris was right, and all but the cheapest English beers could not be produced with a single pure culture (without resorting to the appearance to him distasteful practice of priming) how about two pure cultures, one yeast for the primary fermentation and one for the secondary? This suggestion (really a reiteration of Van Layers process) was put to Morris by Matthew Cannon, a consulting brewer, but Morris discarded such a suggestion as possible but ‘too cumbersome’ in practice. Probably unknown to Morris at the time, for the results were not published, John Simpson Ford, chemist to William Younger’s brewery in Edinburgh had met with similarly disappointing experiences with pure yeast. Ford had also spent time in Copenhagen with Hansen and had returned full of enthusiasm, but repeated extensive trials with single-cell cultures (and with composite cultures) failed to give consistent results with Scottish ales and the technique was abandoned.
To be continued...
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