This is a pretty obvious one. But, as the author points out, it wasn't just the flavour elements created directly by the yeast, but also those it was indirectly responsible for. For example, the amount of unfermented sugars it left behind.
"E. The variety of yeast used.I can't iimagine Saccharomyces ellipsoideus was soemthing any brewer would deliberately pitch into his wort. Different yeasts do produce quite different tasting beers. When Fullers moved from dropping fermenters to conicals they slimmed down their pitching yeast from three strains to one. The main criterion for choosing that one yeast was the falvour it produced. They chose the yeast that was most responsible for the distinctive Fullers flavour.
The well-known "summer sickness" of ale being closely associated with the growth of a variety of Saccharomyces ellipsoideus, it is obvious what a serious effect on flavour the use of faulty yeast may have. There are in fact a great variety of distinct flavours possible, due to particular species of yeasts, some pleasant and therefore desirable, and some otherwise. This is, however, quite apart from the distinctive character of the ale as determined by the rate of both primary and secondary fermentation and the degree of final attenution, which depend to a very great extent upon the kind of pitching yeast employed and the species of Saccharomyces it happens to contain."
Journal of the Federated Institutes of Brewing, Volume 7, Issue 2, March-April 1901, page 200.
This next one is no surprise, either. The mashing scheme, type of copper and method of boiling, type of fermenting vessel and temperature of the fermentation all have an impact on the flavour of the finished beer.
"F. The process of manufacture.
Every part of the process—mashing, boiling, cooling, fermenting, cleansing, racking, and storing—has more or less a direct influence on the quality of the flavour of the ale produced. The man accustomed to drink stone square ale would have little or no difficulty in distinguishing it from ale brewed in unions or tunners. A high mashing heat produces a marked difference in the dextrin-maltose ratio of a wort as compared with a low mashing heat, and thereby influences the rate and degree of fermentation, and, consequently, the flavour. Deep coppers undoubtedly favour a higher boiling heat, and consequently produce more cooking of the wort and a flavour not otherwise found; in extreme cases the wort may be actually "copperburnt," and naturally this would have a marked effect on the ultimate flavour of the ale.
As before mentioned, the prolonged boiling of hops, especially with soft waters, gives an unpleasant, harsh, bitter to the wort, even with the finest flavoured hops.
The temperature of the fermentations largely influences the proportion of those delicate ethers to which the ultimate flavour of the matured ale—more especially strong ales—owes so much.
Every brewer has a dread of the idea of "yeast-bite," and this is not so frequently caused by the use of faulty yeast as by working the yeast faultily. I might here point out that yeast-bite, produced by the yeast parting with a certain amount of its cell-sap and adherent resin to the ale, is in a minor degree constant to the process, hence the peculiar flavour of the ale whilst cleansing. Fortunately, however, it usually passes away as soon as secondary fermentation sets in, and it is only in severe cases or when an excessive amount of yeast pressings or the pressings from a yeast, the cells of which have extremely thin and tender walls, have been added to the beer at rack that the final product is prejudicially affected.
Journal of the Federated Institutes of Brewing, Volume 7, Issue 2, March-April 1901, pages 200 - 201.
How does a stone square ale taste? I've drunk plenty of beer that was brewed in them, but could I spot one? I doubt it, to be honest. Nor a beer from a union set, I fear. Though I have absolutely no doubt that both have an impact on the finisshed beer. Not sure what is meant by tunners. Dropping system? Pontoes?
I can see in brewing records that brewers mashed at different temperatures for different types of beer. Here's a random example from some Whitbread records I happen to be looking at just now.
|Whitbread mashing temperatures|
|Date||Year||Brewer||Beer||Style||strike heat||underlet heat||tap heat||OG||FG||ABV||App. Atten-uation|
|22nd Apr||1965||Whitbread||W||Pale Ale||150º||170º||144º||1036.5||1006.4||3.98||82.47%|
|22nd Apr||1965||Whitbread||Best Ale||Mild||155º||180º||148º||1030.0||1008.3||2.87||72.33%|
|Whitbread brewing record held at the London Metropolitan Archives, document number LMA/4453/D/01/133.|
The mashing temperature was higher for the Mild Ale and, as you would expect, its degree of attenuation was also lower.
London Porter brewers used deep, enclosed coppers because they wanted to boil at a high temperature and darken the wort. For exactly the opposite reason Burton Pale Ale brewers used shallow open coppers - they wanted to avoid the wort becoming darker.
Mmm. Not sure what the bit about fermentation temperatures is saying. Was a higher of lower fermentation temperature needed to get the delicate flavour elements of a matured Ale? My experience of brewing records tell me that, while pitching temperatures varied to some extent, the maximum temperature reached was much the same for all types of beer from a particular brewery. Meaning there was no real difference in the temperature of an X Ale and a KKK Ale fermentation.
We're almost through this bit. Just one more post and we'll be done with flavour factors. Though there will be more on bottling to follow that.