Monday, 23 May 2011

Scottish Ale Brewing in 1870

It's ages since I've kicked this one around. Scotch Ale/Scottish Ale. You can't get enough contradictory evidence. And there's plenty of that when it comes to Scottish brewing.

Before we start, let's discuss the reliability of this source. The author seems to have been Scottish, or at lest lived in Scotland. He had direct contact with someone working in the brewing industry. These are all plus points. One the negative side, this is a very short article in quite a general book.

"Ale. A well-known amber-coloured fermented liquor of considerable strength, but varying in the amount of alcohol which it contains, according to the option of the particular ale brewer. Edinburgh ale contains apparently more saccharine matter unfermented than other ales, and is strong. Burton ale has more hops added, and is hence termed pale bitter ale. The Scotch ale is said to be brewed during the cold months of the year, only one mash of half-an-hour's duration being made, and the heat of the liquor raised to 180°; it is then drained off into the wort copper. The malt is then deprived of all its soluble matter by sparging, or dashing over hot water of 180° for eight or ten times successively, the liquor draining through by apertures placed at the sides of the mash tun, and armed with stopcocks. One gallon of yeast is added to 240 gallons of wort, and the fermentation begun at 50°, and continued for two or three weeks: four lbs. of hops are used to the quarter of malt. The following table by my pupil, Mr. John Wright Currie, of the Perth Brewery, gives the strength of various ales brewed in that establishment. The experiments were made with great care in my laboratory.

Scottish Ales.

Absol. Alcohol per cent.  Extract per cent.  Water per cent. 
Export Ale 7.96 3.75 88.29
India Ale 8.97 2.75 89.28
No. 3 Ale 7.055 5.7 87.25
No. 4 Ale 7.855 6.675 85.47

Scottish Ale Brewing.—To brew 20 barrels of ale, 80 bushels of malt and 80 lbs. of hops are required Three or four barrels of water at 180º are let down into the mash tun, and at the same time the sluice of the malt bung is opened, and the malt and remainder of the liquor at 175° run down together, and stirred. The mashing requires three hours, when the sparger (sprinkler) is fixed to the head of the tun. The sparger is a copper cylinder five or six inches in diameter, closed at both ends, and nearly so to within a foot of the centre, which is open, with a cross division against which a run of liquor by a spout from the copper strikes and sends it round the. tun. An iron bar is fixed across the latter, on which the sparger is placed on a pivot. Its two arms extend the width of the tun, the inferior side of these being pierced with small holes similar to the mouth of a watering-pan, from which as it revolves, the liquor escapes and sprinkles the mash. The water in the boiler being tempered to the heat required for sparging, (185°,) the taps of the mash tun are slacked, and the worts permitted to flow out slowly, the sparger being set in motion—this operation being merely a continuation of the mashing. I may add, that having examined most of the waters used by the Edinburgh ale brewers, I have found them all very hard waters, containing a large quantity of carbonate of lime. If any virtue is to be attributed to the water, it may be presumed that the carbonate may act by neutralizing any acid as soon as it is formed. The 30 barrels of wort, 72 lbs. saccharine extract per barrel, are boiled for half-an-hour, and 40 lbs. hops added; another half-hour's boiling takes place, the remaining hops are added, and the wort boiled for another half-hour. Worts of the gravity of 50 lbs. extract per barrel strengthen 5 lbs. per barrel in one hour's boiling, and worts of 100 lbs. in one and a halfhour strengthen 15 lbs. So that the brewer can easily judge of the amount of boiling required by the use of the saccharometer. The worts, after a quarter of an hour, are run into the hop back, and then spread on the coolers, where they remain twelve hours; during this time they lose one-eighth of their bulk by evaporation. The worts being cooled to 53°, one barrel of wort is run into the gyle, and 6 gallons of yeast added, and thoroughly mixed; the remaining wort is then added. In Scotland, the temperature for commencing the fermentation is about 52.5°, in England 62.5°. In twenty-four hours the first stage ends, the surface being characterized on the edges by a white circle, and irregular patches of white breaking through, and soon being covered with froth. The head of froth is beat down, and the process continued for twenty-four hours more. In eight days the heat has increased 10°. The brewer judges of the period to stop the fermentation by the saccharometer, which indicates the amount of sugar which has been converted into alcohol. The next process is cleansing. In Edinburgh the ale is run finished from the gyle into the casks in which it is sold. In Alloa and Stirling it is run into butts, from which it is rocked into casks, a pint of fillings or prepared wort being put at the same time into each."
"Dictionary of chemistry with its applications to mineralogy, physiology and the arts" by Robert Dundas Thomson, 1870, pages 26 - 27.

In the first paragraph it sounds like he's confusing Burton Ale and Burton Pale Ale. It's a mistake many have made. I'm not convinced by that description of Scottish mashing, either.

Beer details. I always love those. No gravitites, but we do have the ABV. Or is that ABW? It's ABW, I believe. Here are the ABV's:

Beer ABV
Export Ale 9.95
India Ale 11.21
No. 3 Ale 8.82
No. 4 Ale 9.82

All pretty strong. But something doesn't makes sense. Why is the No. 4 stronger than No. 3? Usually they were numbered from the top down, No. 1 being the strongest. At least that's how William Younger did it. Talking of which, here are their versions of No. 3 and No. 4 from the same period. I haven't bothered with the grist, because both were 100% pale malt.

Wm Younger Ales in 1868
Date Year Beer Style OG FG ABV App. Attenuation lbs hops/ qtr hops lb/brl boil time (hours) boil time (hours) Pitch temp dry hops (oz / barrel)
16th Sep 1868 3 Strong Ale 1077 1022 7.28 71.43% 11.39 4.94 1.75 2 58º 19.28
28th Sep 1868 4 Strong Ale 1068 1022 6.09 67.65% 12.50 4.44 2 2.5 59º 17.78

William Younger brewing records held at the Scottish Brewing Archive, document number WY/6/1/2/21

As you can see, they're a good bit weaker than the beers from Perth. But maybe No. 4 was their strongest. Who knows.

The second description of the mashing process is more like it. Let's compare it to the mashing scheme for the William Younger's No. 4 in the table above. That had a strike heat of 170º, as opposed to the 175º given by Thomson. Younger's beer was mashed for 16 minutes, then left to stand for two yours. Thomson isn't very specific, just saying it takes three hours. Younger's beer was sparged twice, at 190º, and 185º. Thomson says 185º. All in all, the two are roughly similar.

I've no idea what he means by wort with 72 lbs saccharine extract per barrel. He can't mean pounds per barrel. The figure would be insanely high - 1200º. 10 quarters of malt, at 80 lbs extract per quarter, would give 20 barrels at 40 lbs per barrel, or 1111º. Checking with the William Younger record, they weren't getting as good a yield as that. Just 65 and 69 pounds per quarter for that No. 3 and No. 4. So at 70 pounds extract per quarter, the OG would be 35 lbs per barrel or 1097º. Still fairly hefty.

Now for the hopping. The rate Thomson gives is 10 lbs per quarter, 4 lbs per barrel. The Younger's No. 3 was 11.4 lbs per quarter, 4.94 per barrel; the No. 4 12.5 lbs per quarter, 4.44 per barrel. A little more. A comparable Whitbread beer, KK from 1868 of 1073º had more still, 14.5 lbs per quarter, 5.23 per barrel.

90 minute boil? That's about right, I suppose. The Younger's beer were boiled a little longer: 1.75 and 2 hours for No. 3, 2 and 2.5 hours for No. 4.

Where I do take issue with Thomson is the matter of picthing temperatures. 52.5º F? Not at Younger. Their pitching temperatures ranged from 56º F for the really strong Ales - over 1100º - to 60º F for beers around 1055º. It wasn't much different at Whitbread, where they pitching at between 58º F and 64º F, depending on gravity. The 1868 KK I've been using for comparison was pitched at 58º F, much the same as the Younger's beers. I can't see any huge difference between English and Scottish practice.

At Younger, the fermentations were faster and warmer than Thomson describes: 5 days at most and rising 15º F or more, hitting a maximum temperature of 70º F

I think he means "racked" rather than "rocked into casks". William Younger did, indeed, rack straight into trade casks.

Has that taught us anything? Are we now more confused than ever? You work it out.


beer guru, jr. said...

those beers sound like my cup of tea. just enjoyed last night, a 10% ABV sprecher czar bourbon barreled russian imperial stout from milwaukee, and an o'so humulus lupulin imperial pale ale at 9% ABV (complete with whole fresh hop in the bottle!), from plover, wisconsin.

Barm said...

This is why I don't write about the history of Scottish beer.