Monday, 24 August 2009

William Younger fermentation temperatures.

Scotch Ales were fermented cold. At least that's what all the brewing manuals say, including "Scottish Ale Brewer" by Roberts. But what do the logs say? Funnily enough, the fermentation is recorded particularly well in Younger's records.

Here's an excerpt from their 1851 records:


The pitching temperature is in the leftmost column. It varies between 55º F and 58º F. The following columns give the temperature throughout the fermentation, where it rose to the high 60's F.

In 1831 pitching temperatures (column 5) were a little lower, but also less consistent:


The coolest is 50º F and the warmest 59º F. The final column is the cleansing temperature (ie end of primary fermentation). This is 70º F in all cases.

In 1885, pitching heats varied from 55.5º F to 61º F, the stronger the beer the lower the temperature.

It looks to me that the temperatures increased as the 19th century progressed and, by the end of it, were about the same as in England. I'll post at greater length on this topic later, when I've extracted more from the logs.

4 comments:

mentaldental said...

I'm not in my book-lined library (I wish) but aren't we in the area of Altbier fermentation temperatures? Some of those pitching temperatures would have made those softee English yeast give up the ghost, I would have thought (50F/10C!).

I guess that this would impact on the flavour profile, reducing "fusel" alcohols to a very low level so these beers would not have been fruity and the malt flavour would have been smooth and prominent. I wonder if this emphasis on malt flavour partly accounts for the "Scottish ales were lightly hopped" idea following a type of backwards logic? ie since they were malty they couldn't be hoppy.

Another thought: these low temperatures could account for the low attenuation of the beers in your previous posts especially if the yeast were actually the same as those soft southern ones!

Recently, on a trip to Leuven, I had a Watney's(!) Scottish Ale. This was very malty and very sweet. I was too sweet for me although the malt flavours were quite nice. It now seems that this might have been more "authentic" than I had thought.

Note for non-Brits: to those of us of a certain age (ask Ron) Watney's was the nadir of UK beer. It was truly awful. They knew it and in the late 70s tried to jump on the real ale revival with their own not-so-real ale called Fined Bitter. This was even worse. How did they make beer so bad? It certainly explains why the Watney workers left their free beer in the brewery and walked across the bridge to drink Youngs on the other bank of the Thames.

Gary Gillman said...

That is very interesting. I still would have thought that there is a differential from English pitching averages, the range given even in the later 1800's sounds lower to me than I have always heard for ale-pitching in England. But let's see what the original sources say.

I wonder what explains this and I have a theory: the Scots were brewing more and more in the traditionally non-brewing part of the year as time went on, possibly assisted by some mechanical refrigeration or other technical developments.

In one of the sources I mentioned earlier, the statement is flatly made that there was no brewing in Scotland - even cool Scotland - from May through to August. I would wager that things changed as time wore on in the 1800's.

Gary

Ron Pattinson said...

The 1831 pitching temperatures are very low. Those for 1851, perhaps a little.

It should be borne in mind that, in general, the stronger the beer, the lower the pitching temperatue.

Just had a look at Barclay Perkins 1850 IBSt, OG 1109, that was pitched at 59 F.

Later Younger's logs (after 1879) show what I would interpret as the use of attemperators. The fermentation temperature drops significantly in the last two days. It looks very much like what happened at Fuller's, where the logs specify when the worts were cooled.

In the logs for 1868 and earlier, the temperature of the wort rises throughout the fermentation, finishing at around 70 F.

I need to investigate the whole topic of fermentation temperature profiles much more. Barclay Perkins' logs also give several temperature readings.

ealusceop said...

Today, you can still find some Scottish ale yeast under the Wyeast brand that can ferment well at 54-55.I know, I tried it. I pitched at 54 and let it rise to 64. It makes a really malty ale, with with very little fruitiness.

By the way, I'm pleased to tell you that I just bought a pub here in Québec, and I will transform it to make a brewpub, where some ales based on old recipes will certainly be brewed. I hope that some of you will want to taste an Old Ale blended from old vatted ale and young, or Porter made the same way! :) This blog is a great inspiration for me!