Saturday, 2 January 2010

Pasteur visits Whitbread

It's uncanny how much of beer's development has been driven by war. Directly and indirectly. Here's a good example: Pasteur wanting to get back at the Germans for the Franco-Prussian war. I suppose brewing better beer is better than building bigger bombs.

"The Franco-Prussian war of 1870-1871 and the subsequent defeat and occupation of parts of France actually provided the stimulus for Pasteur's temporary obsession with beer. Being highly patriotic, he thought that by improving the quality of French  he could 'get back at the Germans' by producing superior prioducts which would gradually replace the hitherto more consistent and popular German beers from their European markets. French beer production at that time was wholly unscientific and it was pure chance that a wholesome batch would be produced. In 1871, Pasteur visited the laboratory of Prof. Emile Duclaux at Clermont-Ferrand and soon became associated with a small brewery at nearby Chamalieres. There he devised a new method of brewing (which he patented on 28 June 1871). The whole ethos of the new method was to avoid contact between beer and the atmosphere as far as possible, and hence reduce the likelihood of contamination. According to Pasteur, beers brewed bt this new method should be called 'Bières de la Revanche Nationale', or 'Revenge Beers'. The brewery at Chamalieres was very small and Pasteur felt the need to work at a far larger consern. Having no desire to visit a German brewery, he turned to England where he arrived in September 1871 with a small entourage. From his base at the Grosvenor Hotel in Victoria he visited a number of London breweries during his fortnight stay. The only surviving record of his visit is of 9 September 1871 when he toured the Whitbread Brewery in Chiswell Street. Although some major British breweries employed microscopes at this time, Whitbread & Co. did not, and during his investigations (he carried his own microscope) Pasteur found serious contaminations in the porter an ale yeast. The beer-finings were also found to be contaminated. As a result of a management meeting, fresh yeast was obtained from a nearby brewery and it was agreed that many of Pasteur's brewing tenetsshould be instigated. On revisiting the Chiswell Street brewery about one week later he found that a microscope had been purchased and new yeast management procedures adopted. Thus, the huge Whitbread tradition of scientific laboratory control of the brewing process emanates from Pasteur's visit."
"Brewing" by Ian Spencer Hornsey, 1999, pages 7-8.
I'm not surprised the finings weren't clean. It was common to use sour, returned beer as a solvent for the finings. Sounds like a good way of spreading an infection to every single barrel you brew.

I found a brewing log from just a couple of weeks after Pasteur's visit. You can see it above. Sadly, it has no mention of the yeast's origin, at least not as far as I can see.


Gary Gillman said...

According to Michael Jackson's World Guide To Beer and his other early books, finings were still being added via a sour beer solution in the 1970's. I have read consistent reports in the 1800's of ditto, which sometimes mention vinegar as an alternate medium.

There must have been a specific reason for this: I don't think it was to save money. Maybe the slight acidulous taste was felt to improve the beer or the action of the finings.


Graham Wheeler said...

'Thus, the huge Whitbread tradition of scientific laboratory control of the brewing process emanates from Pasteur's visit.'

He was unlikely to have had much effect in reality. It ignores the fact that certain bacteria were all part of the character, and also ignores the fact that, at that time, Whitbread were happily deliberately souring beers in huge vats and chucking it into their running beers. To suddenly have clean yeast would would have been a formula for bankruptcy.

This has parallels with Hanson's 'pure yeast system' which was widely adopted in European lager breweries from 1883 onwards, but just didn't work in British ale breweries. The brewers could produce acceptable running beers from an isolated strain, but they were far from satisfactory. Stock ales and old ales failed completely.

This was because the character of British (and presumably Belgian) beers was supplied by a mixture of yeasts and certain bacteria also played a part. It was not until 1904 that brettanomyces was isolated or its significance appreciated, and the major reason for stock ales failing became known. Brettanomyces is an essential component of a stock / old. Today many, if not most, ale breweries use a multistrain yeast, but producing a 'purified' multistrain was not possible until identification techniques evolved. They mostly look the same under a microscope. Even in 1971, most breweries were taking a bucket of yeast from a previous brew and chucking it in the next, just as they were in 1871.

'As a result of a management meeting, fresh yeast was obtained from a nearby brewery and it was agreed that many of Pasteur's brewing tenets should be instigated.'

Is hard to credit that a brewery that had produced world-class beers for 100 years, is going to change their whole brewing ethos because of an irritating little French git who they had never heard of, and was only there because he couldn't produce decent beer himself. I doubt if the British love of the French was any greater than Pasteur's love of the Germans (Most biographers say that he did visit Germany).

A fresh charge of yeast is no big deal. Brewers were always swapping buckets of yeast; it appreciates a change of environment from time to time apparently. All brewers in a region used the same mixture of strains because of this practice. Barclay Perkins yeast would have been little different to Whitbread yeast because of this incestuous relationship, and there is no reason why it should be much less 'contaminated'. Getting a fresh charge of yeast from another brewery would not have solved the perceived problem.

My school science teacher used to regard Pasteur as being the greatest scientific fraud. There is some truth in this, but it is not Pasteur's fault. It is his biographers for attributing 'discoveries' to him that are not his, and that he never claimed to be his own. Much stuff that Pasteur is said to have 'discovered' preceded him by decades. Because Pasteur wrote a paper on a subject during his investigations does not mean that he discovered that subject.

Much of Pasteur's work was as arbitrator between arguing French scientist, settling things 'officially' on behalf of the government. Unless Pasteur influenced Hanson, his influence on British brewing was probably negligible. You would think, by reading some stuff, that the British would not have had a brewing industry if it was not for Pasteur.