Friday, 31 July 2020

Pure yeast culture

I found some tasty titbits on the subject of yeast in a 1924 article by brewing scientist Lloyd Hind. the article in question is called "Beer of the Future".

To be honest, he was a bit wide of the mark in his long-term predictions:

"That the improvement of Continental beers has gone hand-in-hand with the adoption of low fermentation processes does not necessarily imply, that the beer of the future will be lager. In flavour and manner and temperature of serving the two types of beer, top and bottom fermentation are quite distinct, and the choice between the two is one of personal taste. In this country beer drinkers have become so wedded to the flavour of top fermentation beer that they prefer it, and in many cases express dislike for lager. The great majority, however, of those who decry lager have never tasted it as it should be, and generally say they do not like such thin stuff, ignoring the fact that such description does not apply to good lager any more than it does to good English beer."
Journal of the Institute of Brewing, Volume 30, 1924, page 319.

Time has definitely proved him wrong on that one. Lager is undoubtedly the most popular type of beer in the UK today'

Lloyd Hind hoped that UK brewers would give pure yeast cultures another try. A few breweries played around with them in the late 19th century, but gave up when they couldn't get secondary conditioning to work. Not knowing that Brettanomyces performed the secondary fermentation.

"The greatest advance in recent years connected with fermentation has been the introduction of pure cultures and their extensive use in the larger lager breweries; in fact, there are now few of any size that do not avail themselves of the advantages in regularity and quality of beer obtained thereby. So far no success has attended its trials in English breweries. It must, however, be admitted that these trials have not been very extensive, and the sweeping condemnation sometimes passed on any suggestion to adapt pure yeast to English conditions is not justified. The only trials I know of were made many years ago and in connection with beers whose distinctive palate depended on a secondary fermentation. This distinctive Burton flavour I have seen produced in beers as different from normal Burton beers as bottom-fermented stout by an inoculation in the bottle of pure cultures of Bretannomyces, as its discoverer, Clausen, called the particular Torula employed. Conditions are now entirely altered. Secondary fermentation in far the greater number of breweries is a thing of the past, and the desideratum now is to prevent the development of secondary yeast. Under conditions such as these, surely it is time to reopen the investigation and endeavour to put fermentation on a sounder and more certain basis."
Journal of the Institute of Brewing, Volume 30, 1924, page 330.

Of course, there are still UK breweries which don't use a pure culture. Adnams, for example have two strains in their pitching yeast. Who knows what's in Harvey's yeast. I'm guessing more than just one strain of Saccharomyces and Denbaromyces.

1 comment:

Martyn Cornell said...

Good to see a man using the expression "secondary fermentation" properly, instead of, as done by Camra and too many others, using it to describe the continuation of the primary fermentation when the beer is in trade casks.