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.