Bass and Allsopp IPA 1851 - 1901

Just to show how much of an outlier those strong Allsopp and Salt beers were, here's a selection of IPAs from Bass and Allsopp. They span the whole of the second half of the 19th century.

The strongest is 7.58% ABV - well short  of the strong IPAs, whether that Lancet article is listing ABV or ABW. They average out to around 1065º and just under 7% ABV. Which is exactly what I would have expected. 1065º was the classic OG for Burton-brewed IPA.

I.m at a total loss as to how to explain those two strong IPAs. They are very different to any 19th-century IPA that I've seen. It leaves me wondering if they've been misidentified and are actually Burton Ales rather than Pale Ales. Though The Lancet is a pretty reliable source so I'm disinclined to believe that.

Let me know if you have any ideas.

Bass and Allsopp IPA 1851 - 1901
Year	Brewer	Beer	OG	FG	ABV	App. Atten-uation
1851	Allsopp	Export IPA	1057.1	1009	6.32	84.59%
1851	Allsopp	Export IPA	1060.8	1009	6.84	85.86%
1869	Allsopp	Pale Ale	1064.2	1010	7.18	83.82%
1869	Allsopp	Pale Ale	1068.5	1013	7.19	80.32%
1901	Allsopp	India Pale Ale, Red Hand	1061.6	1009	6.80	85.27%
1851	Bass	Domestic IPA	1064.0	1013	6.69	80.00%
1852	Bass	Domestic IPA	1073.7	1019	7.11	73.95%
1862	Bass	Pale Ale	1067.8	1014	7.04	78.91%
1862	Bass	Pale Ale	1069.0	1017	6.80	75.07%
1862	Bass	Pale Ale	1069.5	1017	6.91	75.68%
1862	Bass	Pale Ale	1063.2	1012	6.69	80.38%
1862	Bass	Pale Ale	1066.9	1016	6.74	76.68%
1869	Bass	Pale Ale (brewed 2nd Jan 1869)	1065.9	1010	7.33	84.50%
1869	Bass	Pale Ale (brewed 24th Dec 1868	1065.4	1013	6.96	80.87%
1869	Bass	Pale Ale (brewed 27th Jan 1869)	1066.7	1012	7.20	82.33%
1869	Bass	Pale Ale	1067.0	1013	6.81	80.31%
1869	Bass	Pale Ale	1056.5	1010	5.98	82.08%
1870	Bass	India Pale Ale	1060.0
1880	Bass	Pale Ale	1055.2	1017	4.90	68.48%
1887	Bass	Pale Ale	1064.2	1009	7.08	84.75%
1887	Bass	Pale Ale	1063.5	1010	7.08	85.04%
1888	Bass	Pale Ale	1069.6	1011	7.58	83.82%
1888	Bass	Pale Ale	1069.0	1011	7.58	83.77%
1896	Bass	Pale Ale	1060.8	1007	6.98	87.97%
1898	Bass	Pale Ale	1064.9	1016	6.43	76.02%
1901	Bass	Dog's Head	1065.6	1003	8.06	94.59%
1901	Bass	White Label	1063.8	1007	7.25	87.73%
1901	Bass	draught Pale Ale	1064.0	1013	6.48	78.03%
		Average	1064.6	1011.9	6.89	81.51%
Sources:
The Lancet 1852, vol.1, 1852, page 474
British Medical Journal August 28th 1869, page 245
Wahl & Henius, pages 823-830
The Lancet 1852, vol.1, 1852, page 474
The lancet 1853, Volume 2, 1853, page 631.
Bass price list
Chemie der menschlichen Nahrungs- und Genussmittel by Joseph König, 1889, page 835
Brockhaus' konversations-lexikon, Band 2 by F.A. Brockhaus, 1898