Friday, 6 August 2010

Scottish fermentation temperatures

I don't want to start an argument. Really. I really don't. Just present a few facts and leave the rest to you? Don't complain if the information presented isn't what you think it should be. I'm just the messenger here.

Our today theme: were Scottish beers fermented colder than English ones?

To start, a random set of quotes. They were dead easy to find. An indication of how often this claim is made.

"Scotch ales are fermented at much lower temperatures (50-60F) than traditional ales, and the fermentation can take several weeks to complete as a result."

"Scottish ales were usually fermented slow and cold (like 50-55 degrees for weeks) compared to their English counter parts (65-70 degrees for days). The result was less attenuation and cleaner flavor."

"Historical research informs us that classic Scotch and Scottish ales require cool fermentation and low attenuation."

"The natural selection for the yeast in Scotland favors yeast which will ferment well in the cold temperatures there."

"The Scots brewing tradition is one of cool fermentations (’cause, uh, it’s cold in Scotland), and the yeasts used tend to like a long, slow ferment, at near lager temperatures."

"Long, cool fermentation leads to clean malt character (which may include some faint peat or smoke character)."

Now for some historical research.

This is part of a 1913 brewing record from William Younger, of Edinburgh. It records the fermentation of several brews:

Here's a Fuller's one from 1914:

You're probably as lazy as me, so I'll extract the relevant information for you.

The Younger's beers were pitched at:

59.5, 59.5, 59.5, 60, 60, 61.5º F

None of the fermentations took more than 4 days. The maximum temperatures the fermenting worts reched were:

69, 68.5, 67.5, 70, 69º F

Fuller's pitching temperatures:

60, 59.5º F

The fermentations took six days. The maximum temperatures were:

67, 67º F


Ant Hayes said...

Has there been a good book on Scottish brewing practice since The Scottish Ale Brewer and Practical Maltster, by W. H. Roberts (published in 1847)?

Ron Pattinson said...

Ant, not as far as I'm aware. That's why everyone gets things so wrong. They base everything on his book. From what I've see of Younger's brewing records, most of what Roberts says about Scottish brewing practices no longer applied after 1850.

Graham Wheeler said...

Again you are not comparing like with like. By the twentieth century there was ha'porth of difference between the beers brewed by almost every brewery in the Kingdom. Edinburgh is probably a bad place to do comparisons too, due to the river giving them the ability to serve English major cities, even in pre-railway days. Post railway days things changed enormously; beers were brewed to match markets and many distinctive styles merged into more or less the same thing.

If you are going to pick on Scotch Ale, then you should choose a period when it was a distinct style, along with Dorchester Ale, Windsor Ale, and so on; not some arbitrary label slapped an an anglicised product or source of origin.

There is enough stuff in contemporary books that refutes your assertion. I have chosen Booth because he's cut and pasteable, I have several other examples, all later than Booth as it happens, but there must be earlier examples in more extensive libraries than mine.

"THE distinguishing characteristics of Scotch ale, are paleness of colour, and mildness of flavour. The taste of the hop never predominates, neither in its stead do we discover that of any other ingredient. It is perhaps more near to the French pale wines, than any of the other ales that are brewed in this country. Like them, too, it is the result of a lengthened fermentation. The low heat at which the tun is pitched confines the brewing of Scotch ale to the colder part of the year. During four or five of the summer months, the work (except perhaps in some houses for table beer) is completely at a stand, the utensils are limed down, and the greater part of the workmen discharged. No strong ale is either brewed or delivered ...

"The first heat of fermentation, in the Scotch method, is as low as possible, consistent with the action. The favourite heat is 50, a point at which chemists have generally asserted that the vinous fermentation could not exist, but 45 and 46 are by no means uncommon in the manuscript brewing-books that now lie before us. Even in the coldest weather, the lowness of heat is not to be feared. The fermentation sometimes continues for three weeks, and a fortnight would be a pretty fair average."

Art of Brewing, Booth, 1829.

Booth tackles three things that you have contradicted; colour, hop character, and now fermentation temp. Late 19th - early 20th-century economics probably preculuded three week fermentation periods when under competition.

Ron Pattinson said...

Graham, what point are you trying to make?

I picked out those two particular log excerpts because I had an English and a Scottish one from the same time.

I could also have picked a much earlier Younger's one - 1847 - which shows exactly the same. Pitching temperatures 55-61º F, fermentations lasting 4 to 8 days, maximum fermentation temperatures of 64-71º F.

Look, all the people who write this bollocks about Scottish beer don't say "before 1820 Scottish beer was such and such". Either they don't mention any dates, or they use the present tense.

And look, Edinburgh was the centre of Scottish brewing. Saying it's not typical of Scottish brewing is like saying London isn't typical of Porter brewing.

So far no-one has come up with any actual brewing records that confirm any of the junk usually repeated about Scottish beer. Yeah there's all sorts of stuff in books about Scotch Ale. I've posted loads of it (look under the tag Scotch Ale). I prefer to believe the brewing records.

Gary Gillman said...

Ron, do these 1914 records state the time of the year these operations occurred? If it was in different seasons wouldn't that explain something? (E.g., say the English brewing was in late autumn and the Scots one in late spring).

Also, before air conditioning existed, how they did get a "target" fermentation temperature, assuming it was adjusted artificially?


Andy said...

I have to agree,why would the brewer record the wrong information in his logs?

Ron Pattinson said...

Gary, the time of year is irrelevant. Brewers fermented at the same temperature all year around.

How did they control the fermentation temperature? Easy - with attemperators. They'd been around since the 18th century. They're metal pipes immersed in the fermenter through which cold water is passed.

If you look at the Fuller's image you'll see towards the bottom "liquor on". That's when they used the attemperator to drop the temperature at the end of the fermentation.

Brewers did vary pitching temperatures, but that was connected with a beer's gravity. The stronger the beer, the lower the pitching temperature. So very strong beers would be pitched at 57º F and weak ones at 61º F.

Gary Gillman said...

That is helpful, but Booth's comments (and there are similar in Stewart and Thompson's book from the late 1840's - who were Scots too, one a practical brewer, one a University chemistry teacher) indicate to me he was not talking about attemperation. Evidently (or it is to me), he was talking about traditional Scots ale brewing practice, the one that made the famous strong, sweet Scotch ale.

I accept that this changed in the later 1800's, for all the reasons that have been mentioned. And therefore, loose statements in current consumer-oriented literature about how Scotch ale is fermented should be taken with a grain of salt.

But the core of it, that Scotch ale should be fermented at a low temperature, 50 F or lower, remains valid in my view as the key to understanding part of the traditional character of Scotch ale. If I was a homebrewer making such a beer, I would want to use the Booth range of temperatures and fermentation time. No question that later it changed and the beer styles became more uniform if not muddled, but that is how I see it.


Adrian Avgerinos said...

Your title is incomplete. It should read, "Scottish fermentation temperatures in 1914 at Fullers."

In addition, it was YOUR blog where I read that Edinburgh ales were fermented cooler than their London counterparts.

Ron Pattinson said...

Adrian, not sure what you mean about the title.

I wrote the post about cooler fermentation temperatures before I got my hands on any Scottish brewing records.

I think at one time Scottish beers probably were fermented colder. I'm also pretty sure that long after that ceased to be true, people kept repeating the story.

In the brewing records I've looked at, I can find no significant differences in fermentation temperatures between England and Scotland. That's based on William Younger's records from 1847 to 1950, Usher's from 1885 to 1928 and Maclay's from 1909 and 1951.

Alistair Reece said...

I am fairly sure I am going to get slaughtered for this, but there we go, and I say this as a Scot.

I am becoming convinced that the whole Scottish ale vs English ale is something of a misnomer based on a prevailing nationalism from the mid 19th century.

Better surely to see that ales produced in Scotland, England, Wales and Cornwall are all regionalised expressions of a common brewing tradition?

Graham Wheeler said...

There must be a name for people that pick on other peoples well meaning statements and use the "apparent" deficiencies of those people to inflate their own importance or authority.

You pick up on semantics, yet you seem unable to understand the distinction between Scotch ale, which was a definitive style until about 1850, when it went defunct (along with porter); and Scottish Ale which is a place of manufacture.

You also seem to be patently unable to grasp the difference between a beer style and an arbitrary label. Far worse, really, than the BJCP crowd.

"That's why everyone gets things so wrong."

Oh dear! everybody is wrong except Patto. Your, so called, research says no more than in 1913 there was little difference between Fuller's fermentation temperatures and Youngers. That would come as no surprise to anybody that knew anything about the development of brewing.

You extrapolate far too much from scant information and produce far too many sweeping statements. For someone that professes to be an 'istorian, it is decidedly unprofessional.

you have to understand, or at least look at, the wider picture to qualify.

Thomas Barnes said...

This is very interesting information, but without knowing more about what sort of beer was being brewed and the brewing technique used, it doesn't quite prove your point.

If Younger's was brewing English-style beer, as Graham Wheeler suggests, it would make perfect sense for them to follow English brewing practice. They might have even been using English ale yeast strains to do it.

If they were brewing Scotch ale or a "shilling ale" then there might be other things going on. In that case, your point about higher fermentation temperatures holds, but, perhaps, these beers were cool conditioned to smooth out their character. That would leave a nub of truth to the "traditional" assertions about cool fermentation.

What I find interesting is the differences between Fuller's and Younger's practices.

Looking closely at the records, it appears that both Younger's and Fuller's were doing primary fermentation over a 4 day period, keeping their yeast in the mid-60s until the 4th day, when it was cooled into the high 50s before being racked. In both cases, SG drops off nicely, meaning happy yeast, but the beer gets cooled before the beer quite gets to terminal gravity.

The difference is that Younger's fermentation profile looks a bit like a bell curve. Lower initial temperature, a spike in temperature as the yeast hits high krausen on the second day, then a tapering off of temperature as fermentation slows. The beer is then cooled to a slightly lower temperature than the Fuller's beer before being racked.

By comparison, Fuller's temperatures almost never vary from 67 degrees. Either someone was fudging the data or they had much more sophisticated temperature control techniques.

What that says to me is that, even if Younger's and Fuller's were using the same basic strain of yeast, they were treating it differently.

Steve said...

is this an attempt to make us look back at all your other Scotch ale/Scottish ale posts?

Waiting for Ron's reply to Graham's 2nd comment is high drama indeed, like a soap opera for beer nerds.

Anonymous said...

Plenty of Scottish ale after 1850 called Scotch.

Gavin said...

I lived in the North East for a few years. Contary to what most Belgiums call Scotch Ale or what the BJCP says, Scotch is a Geordie drink. Scotch is about 3.6 ABV, it ranges in colour from a dark brown bitter colour or closer to a dark mild, though not as dark as Mcewans 60 shilling. It is drunk by old men in working mens clubs,it's a bit like Mild ale, though some examples are a bit like a malty bitter

Ron Pattinson said...


"You pick up on semantics, yet you seem unable to understand the distinction between Scotch ale, which was a definitive style until about 1850, when it went defunct (along with porter); and Scottish Ale which is a place of manufacture."

Try looking at my earlier posts and you'll see I make a distinction between Scotch Ale and Scottish Ale. Though the line between the two isn't as clear as some might believe.

Porter went defunct in 1850? What the fuck are you talking about? Talk about sweeping and unfounded statements. I know, you have this bizarre idea that everything after then is "fake" Porter.

The Younger's beers shown are a mix of everything - 60/-, 80/- XXX, 140/-. The 140/- would certainly qualify as a "Scotch Ale".

As for the rest of your points, Graham, a bit rambly and abusive. Extrapolating from scanty information? This was just a simple example. I have the details of several hundred English and Scottish beers. How many actual beers has anyone else ever compared?

Take a look if you don't believe me:

Or does this not count as "research" in you mind.

Oh, and don't call me patto. That name's reserved for my friends.

Barm said...

Gavin's comment is a good example of the confusion caused by the term "Scotch Ale". There are at least three kinds of modern-day beer the term was used for, in addition to the pale Scotch Ale Booth talks about: the weak session beer sold in the North East, the No. 3 Scotch Ale sold in London by Younger's; the strong dark Scotch Ale sold in Belgium. Beers with little in common except that they were sold outside Scotland. Brewers will call a beer anything to sell it. In the 1950s Younger's sold No. 1 as Strong Scotch Ale in England and Barley Wine in Ireland. In Scotland it was just Strong Ale.

Thomas Barnes said...

Velky Al said...

"I am becoming convinced that the whole Scottish ale vs English ale is something of a misnomer based on a prevailing nationalism from the mid 19th century."

It wouldn't be the first time that brewers played on regional or national sentiment to sell their products.

If you confine your hypothesis to brewing operations from the latter 19th century on, I agree with you.

By about 1870, once modern industrial brewing practice had been more or less figured out, the ingredients, technical processes and transport infrastructure available allowed for increased homogenization of beer styles. The only limits were economics, politics and customer preferences.

Before then, there would have been much more regional variation. Brewers would have been more dependent on locally-grown, locally-processed ingredients and wouldn't have had the technical expertise to do things such as water treatment or yeast culturing.

Ron Pattinson said...

Thomas, I've seen distinct regional variations after 1870. Irish and London Porter, for example. And Scottish brewers were already importing many of their ingredients before 1870. Both hops and malt.

Brewers often used each others yeast.

Thomas Barnes said...

Ron Pattinson said...

"Thomas, I've seen distinct regional variations after 1870."

Regional variations exist to this day, so I'm not disputing their existence after 1870.

What I was trying to say is that after that period (or maybe, more properly, after about 1885) there were no [i]technical[/i] reasons why a brewer couldn't brew any sort of beer he pleased. All the modern malts were available, yeast culturing was understood, and modern sanitary practices were in place.

Before 1870 or so, I think that brewers were much more constrained in what they could brew. This wasn't so much due to limitations of malts or hops (those could be imported from around the world with relative ease), but rather ignorance of important aspects of brewing, or, at best, limited ability to control them.

Ron Pattinson said...

Thomas, I think people today often overestimate the effect of scientific developments on brewing. Sure brewers weren't always fully aware of the science, but had learned empirically how to handle thins like yewast.

The only exception I would make to this is the understanding of water chemistry. Even that doesn't appear to have bothered brewers as much as many today believe. Like say, brewing pale beers in London. WHich went on for centuries before water treatment.

Thomas Barnes said...

Ron, I'm impressed by the shrewd empirical understanding that some "pre-modern" brewers had of water chemistry.

For example, the author of "London and Country Brewer" talks about certain waters having a mineral flavor or not being able to be work soap into a lather - classic signs of hard water. He also discusses the merits of rainwater (generally very soft) vs. well water.