Thursday 11 April 2013

Drybrough PI 1914 - 1919

There's a lot of stuff that I do behind the scenes that doesn't register here. Background research. Sometimes it takes months rather than days or hours. Like plodding through the muddy fields of Drybrough's brewing records.

They've been taking me forever to get through, for a couple of reasons. First, I've loads of them. Because of the multiple beer per page format I've photos of several thousand individual beers. That takes a lot of getting through. Second, they aren't the easiest records to understand. I'll be honest: there are many things I don't understand at all. Like how they gyled their Milds.

The combination of lots of work and being put off by comprehension issues has left me struggling - or avoiding - Drybrough's records for the last six months. I've finally worked my way through WW I. I'm hoping the hours of toil have been rewarded with an excellent set of data. I've more than enough, really. Which has been putting me off posting, too. The tables needed some radical pruning to get them to a reasonable size.

Preamble over, what will be a very, very long series bounces down with a look at Drybrough's PI during WW I. This was their biggest seller, probably at least 50% of production. Which means there's something immediately apparent about its strength. It's low for a standard beer of the day. Remember that X Ale (ordinary Mild) was over 1050º in London.

This might explain that:


Output and average OG by UK region in 1914
bulk barrels average OG
England 31,737,384 1051.69
Scotland 2,288,481 1047.67
Ireland 3,532,902 1065.93
UK 37,558,767 1052.80
Source:
Brewers' Journal 1921, page 246.

The average OG was a good bit lower in Scotland than in England. So no surprise the Drybrough's biggest seller was weaker.

A philosophical question before we get bogged down in detail: what style of beer was PI? The name implies it was an IPA. However in 1920 the names of all Drybrough's Pale Ales were changed from PI to PA. PA presumably standing for Pale Ale. There was no change in the character of the beers. So were they IPA's or Pale Ales? It's this sort of shit that has me seriously considering just using Pale Ale as the style for any Pale Ale or IPA. There is no way of differentiating the two styles, other than what the brewer called them.

I've picked Whitbread FA to use as a comparison because it's their Pale Ale with the closest gravity to Drybrough PI. Just 3 degrees or so higher at the start of the war, two at the end. Between 1914 and 191 the gravity of PI fell from 1044º to 1030º - a drop of 32%. In percentage terms, FA saw exactly the same decline, 32%, from 1047.4º to 1032.4º. Interesting, that.

Fuller's AK is an even better match for PI, starting and ending the war at just about exactly the same gravity. Though, interestingly, it did fall lower, bottoming out at 1026º in 1918.

FA was the weakest of Whitbread's Pale Ales, while PI, at least at the start of the war, was in the middle of Drybrough's, with PI 60/- above and PI 48/- below. Fuller's began the war with two Pale Ales, AK being the weaker.

There's one very obvious difference between PI and the London beers: the hopping rate. Even taking into account the slight difference in gravity, PI was hopped at about half the rate of FA and about two thirds the rate of AK. This must have given PI a very different flavour profile. In fact, PI has fewer hops than Whitbread's X Ale, which in 1914 was hopped at 6 lbs per quarter, 1.3 lbs per barrel (it was a bit stronger at 1053º).

The next difference which would have accentuated the flavour profile mismatch even more: the degree of attenuation. It averaged 69.5% for PI, 77.2% for FA and 79.8% for AK. As a result, PI would have tasted much sweeter than FA and AK. Not that, the FG of PI was higher than of FA, despite being a few points lower in gravity. 

You can see that, while the boil times of all three beers fell during the war, those of PI fell the most. They started a little longer than FA and ended a little shorter. Breweries were prompted to cut theit boiling times in attempt to reduce their use of coal, which is short supply.

The pitching temperatures were very similar. The ones listed for Drybrough aren't the real pitching temperatures, but those just after the start of fermentation. Based on later records where the real pitching temperature is given, the beers in the table were pitched at 59-60º F.

There's not much difference between the length of fermentation, except in the early war years. From 1917,  PI, FA and AK all averaged around 7 days from pitching to racking.

The maximum fermentation was a couple of degrees higher for PI than AK. Though in the case of both beers it also fell a couple of degrees during the war.

There's no way that Drybrough PI would have been considered a Bitter in London. The hopping is far too low and the final gravity too high. To be honest, it looks more like a Light Mild.

Next time we'll be looking at the grists.

Drybrough PI 1914 - 1919
Date Year Beer OG FG ABV App. Atten-uation lbs hops/ qtr hops lb/brl boil time (hours) boil time (hours) boil time (hours) Pitch temp max. fermen-tation temp length of fermen-tation (days)
29th Dec 1914 PI 1044.0 1015.0 3.84 65.91% 4.97 0.91 2 2.17 62º 67º 10
5th Jan 1915 PI 1044.0 1014.0 3.97 68.18% 5.03 0.92 2 2 2.17 62º 70º 8
8th Jan 1915 PI 1044.0 1014.0 3.97 68.18% 4.59 0.84 2 2 2.17 62º 69º 8
14th Jul 1915 PI 1044.0 1013.0 4.10 70.45% 4.99 0.90 2 2 2.17 62º 71º 7
14th Dec 1915 PI 1042.0 1013.0 3.84 69.05% 5.07 0.93 2 2.17 63º 69º 8
7th Jan 1916 PI 1045.0 1014.0 4.10 68.89% 5.02 0.93 2 2 2.17 63º 70º 7
18th Jul 1916 PI 1043.0 1013.0 3.97 69.77% 3.99 0.72 2 2 2.17 63º 70.5º 7
4th Aug 1916 PI 1043.0 1013.0 3.97 69.77% 4.03 0.74 2 2 2.17 63º 71º 8
18th Oct 1916 PI 1042.0 1013.0 3.84 69.05% 3.95 0.73 2 2 2.17 63º 71º 8
16th Jan 1917 PI 1041.0 1012.0 3.84 70.73% 3.95 0.68 2 2 2.17 63º 69º 4
13th Feb 1917 PI 1036.0 1012.0 3.18 66.67% 4.04 0.61 2 2 2.17 63º 68º 7
14th Aug 1917 PI 1035.0 1010.0 3.31 71.43% 4.04 0.56 2 2 2.17 61º 67º
15th Aug 1917 PI 1034.0 1010.0 3.18 70.59% 3.99 0.57 2 2 2.17 62º 71º 5
16th Aug 1917 PI 1035.0 1010.0 3.31 71.43% 3.74 0.56 2 2 2.17 63º 72º 6
17th Aug 1917 PI 1035.0 1010.0 3.31 71.43% 4.04 0.57 2 2 2.17 62º 66º 6
17th Aug 1917 PI 1029.0 1009.0 2.65 68.97% 4.04 0.47 2 2 2.17 62º 64º 6
20th Aug 1917 PI 1034.0 1010.0 3.18 70.59% 4.04 0.58 2 2 2.17 63º 71º 5
19th Oct 1917 PI 1033.0 1010.0 3.04 69.70% 3.98 0.55 2 2 2 62º 64º 8
23rd Oct 1917 PI 1037.0 1011.0 3.44 70.27% 3.99 0.62 2 2 2 62º 67º 8
6th Nov 1917 PI 1038.0 1013.0 3.31 65.79% 3.99 0.66 2 2 2 63º 68º 8
21st Dec 1917 PI 1037.0 1011.0 3.44 70.27% 5.16 0.79 2 2 2 62º 67º 7
22nd Jan 1918 PI 1037.0 1011.0 3.44 70.27% 5.05 0.78 2 2 2 63º 68.5º
27th Jan 1918 PI 1037.0 1011.0 3.44 70.27% 4.98 0.78 2 2 2 63º 68.5º
19th Feb 1918 PI 1038.0 1010.0 3.70 73.68% 4.98 0.79 2 2 2 63º 67.5º 7
26th Feb 1918 PI 1037.0 1010.0 3.57 72.97% 5.03 0.79 2 2 2 63º 68º 7
5th Mar 1918 PI 1038.0 1010.0 3.70 73.68% 4.98 0.82 2 2 2 63º 69º 7
8th Mar 1918 PI 1038.0 1011.0 3.57 71.05% 5.00 0.87 2 2 2 64º 67º 8
23rd Jul 1918 PI 1030.0 1009.0 2.78 70.00% 4.93 0.63 1.5 1.5 1.5 64º 68º 7
13th Aug 1918 PI 1030.0 1009.0 2.78 70.00% 5.02 0.67 2 2 64º 67º 7
23rd Oct 1918 PI 1030.0 1009.0 2.78 70.00% 5.01 0.66 1.5 1.25 1.25 62º 66º 6
29th Oct 1918 PI 1030.0 1010.0 2.65 66.67% 5.02 0.62 1.33 1.33 63º 67º 7
24th Jan 1919 PI 1030.0 1009.0 2.78 70.00% 4.93 0.63 1.33 1.25 1.25 61º 63º 7
28th Jan 1919 PI 1030.0 1010.0 2.65 66.67% 5.00 0.64 1.33 1.25 1.25 62º 64º 8
7th Feb 1919 PI 1030.0 1010.0 2.65 66.67% 5.00 0.72 1.33 1.33 62º 64º 7
2nd Jul 1919 PI 1029.0 1010.0 2.51 65.52% 5.00 0.60 1.33 1.25 1.25 62º 64º 7
3rd Jul 1919 PI 1031.0 1010.0 2.78 67.74% 4.93 0.65 1.5 1.25 1.25 61º 64º 8
8th Jul 1919 PI 1030.0 1009.0 2.78 70.00% 5.11 0.68 1.5 1.25 1.25 62º 63º 7
Source:
Drybrough brewing record held at the Scottish Brewing Archive, document number D/6/1/1/3


Fuller's AK 1914 - 1919
Date Year Beer OG FG ABV App. Atten-uation lbs hops/ qtr hops lb/brl boil time (hours) boil time (hours) Pitch temp max. fermen-tation temp length of fermen-tation (days)
20th Nov 1914 AK 1044.3 1009.1 4.65 79.38% 7.33 1.34 1.5 1.75 60.5º 68º 8
8th Dec 1914 AK 1044.1 1009.4 4.58 78.63% 7.35 1.36 1.5 1.75 58.5º 68º 8
2nd Jul 1915 AK 1044.5 1009.7 4.61 78.22% 7.84 1.42 1.5 1.75 59.5º 69º 8
1st Jun 1916 AK 1043.9 1009.7 4.53 77.93% 8.20 1.54 1.5 1.75 60º 67º 9
3rd Aug 1916 AK 1042.7 1008.9 4.47 79.23% 8.13 1.46 1.5 1.75 60º 67º 8
26th Oct 1916 AK 1041.0 1006.6 4.54 83.78% 8.44 1.43 1.5 1.75 59.5º 66º 8
3rd Nov 1916 AK 1041.7 1005.8 4.74 86.04% 8.18 1.46 1.5 1.75 60º 66º 8
12th Jan 1917 AK 1041.8 1007.8 4.50 81.44% 8.17 1.40 1.5 1.75 59º 64º 8
19th Jan 1917 AK 1040.7 1007.5 4.40 81.63% 8.48 1.44 1.5 1.75 59º 64º 7
13th Apr 1917 AK 1041.5 1008.3 4.39 79.99% 8.49 1.41 1.5 1.75 59.5º 65º 8
20th Jun 1917 AK 1038.6 1006.4 4.27 83.51% 8.53 1.45 1.5 1.75 60º 64º 7
8th Aug 1917 AK 1035.4 1006.4 3.84 82.00% 9.67 1.43 1.5 1.75 60º 70º 7
1st Nov 1917 AK 1035.9 1007.8 3.73 78.41% 9.64 1.47 2 60º 65º 7
14th Nov 1917 AK 1036.1 1008.3 3.68 76.98% 9.66 1.43 1.5 1.75 60º 65º 6
2nd Jan 1918 AK 1035.5 1007.5 3.70 78.92% 9.72 2.24 1.5 1.75 60º 65º 6
16th Jan 1918 AK 1036.1 1011.1 3.32 69.35% 8.70 1.28 1.5 1.75 60º 65º 5
11th Apr 1918 AK 1026.1 1005.5 2.73 78.81% 9.99 1.10 1.5 1.75 60.5º 64º 6
20th Jun 1918 AK 1026.2 1005.5 2.73 78.84% 9.68 1.11 1.5 1.75 60º 64º 5
7th Nov 1918 AK 1025.7 1005.0 2.74 80.60% 9.45 1.09 1.75 60º 66º 5
16th Jan 1919 AK 1026.1 1006.1 2.64 76.62% 9.25 1.10 1.75 60.5º 66º 5
15th Apr 1919 AK 1026.0 1004.4 2.86 82.98% 9.04 1.08 1.75 61.5º 65º 5
19th Jun 1919 AK 1028.2 1004.7 3.10 83.28% 9.72 1.14 1.5 1.5 62º 65º 5
25th Jun 1919 AK 1028.0 1005.3 3.01 81.21% 9.72 1.16 1.75 61.5º 65º 6
27th Aug 1919 AK 1030.5 1006.9 3.12 77.31% 9.96 1.28 1.5 1.5 60º 65º 6
Source:
Fuller's brewing records held at the brewery.

Whitbread FA 1914 - 1919
Date Year Beer OG FG ABV App. Atten-uation lbs hops/ qtr hops lb/brl boil time (hours) boil time (hours) Pitch temp length of fermen-tation (days)
28th May 1914 FA 1047.4 1013.0 4.55 72.55% 11.02 2.24 1.5 1.75 58.5º 6
4th Jun 1914 FA 1047.1 1013.0 4.51 72.39% 10.97 2.22 1.5 1.75 58.5º 6
22nd Jun 1914 FA 1047.6 1014.0 4.45 70.62% 10.98 2.23 1.83 2 58.5º 6
8th Oct 1914 FA 1048.5 1015.0 4.43 69.06% 9.84 2.07 1.5 1.58 58.5º 6
29th Jan 1916 FA 1045.4 1013.0 4.29 71.38% 9.95 1.98 1.5 1.75 60º 7
18th May 1917 FA 1045.7 1010.0 4.72 78.12% 12.08 2.48 1.5 2.25 60º 7
24th Jul 1917 FA 1033.2 1005.0 3.74 84.96% 13.89 2.03 1.75 1.75 60º 7
11th Oct 1917 FA 1035.2 1005.0 3.99 85.79% 11.51 1.72 1.75 1.83 60º 7
5th Jun 1918 FA 1032.7 1008.0 3.27 75.52% 12.13 1.71 1.5 1.75 62º 7
3rd Jul 1918 FA 1032.6 1007.0 3.38 78.51% 11.97 1.68 1.5 1.92 62º 7
30th Oct 1918 FA 1032.4 1005.0 3.63 84.57% 11.97 1.70 1.5 1.75 62º 7
5th Feb 1919 FA 1032.1 1006.0 3.46 81.33% 11.92 1.70 1.5 1.75 62º 7
19th Mar 1919 FA 1032.4 1007.0 3.36 78.40% 11.85 1.67 1.17 1.42 62º 7
Source:
Whitbread brewing record held at the London Metropolitan Archives document number LMA/4453/D/01/079, LMA/4453/D/01/080, LMA/4453/D/01/081, LMA/4453/D/01/082 and LMA/4453/D/01/084.

4 comments:

Rob said...

"There is no way of differentiating the two styles, other than what the brewer called them."

Hooray for America, fixing problems caused by Britain since 1776!

They may be arbitrary and unhistorical, but American guidelines/definitions of IPA and PA [mostly] fix that problem. :)

Ron Pattinson said...

Rob,

au contraire, I think they've just confused things even more.

johnk said...

Hi Ron, did you forget to list the grist you said you were going to give us next.
Would really appreciate it if you can.
Thanks JK

Ron Pattinson said...

John,

it's coming. I've just been too busy/lazy to put in the brain work.