Saturday 5 July 2008

Pale Ale gravities 1839 - 2005

It's great fun playing with my mega-gravity table, now that I have some modern stuff in there. I've been looking at Pale Ale this time.

I've averaged the gravity of several hundred samples of Pale Ale. I realise that this doesn't give a true average gravity, but it does give an indication of general trends. I suppose I should also define what I mean by Pale Ale. All types of Bitter and Pale Ale. Splitting apart Bitter and Best Bitter just isn't feasible.

Anyway, here are the figures:

1839-1899 1058.55 (4 samples)
1901-1917 1058.9 (12 samples)
1926-1930 1046.7 (83 samples)
1930-1939 1046.7 (235 samples)
1940-1949 1037 (292 samples)
1950-1959 1038.8 (290 samples)
1960-1968 1040.7 (86 samples)
2002-2005 1041.7 (557 samples)

It's quite scary how the 1926-1930 and 1930-1939 came out exactly the same. It looks a reasonable enough average to me for the period. The figure of 1037 is significant, too. For many years during the 1940's that was the average gravity for all beer brewed demanded by the government.

If you compare the same Mild over the same period, you'll notice that its gravity fell significantly in the 1930's:

1839-1899 1068.6 (12 samples)
1901-1917 1050.3 (13 samples)
1920-1926 1041.9 (50 samples)
1933-1939 1036.2 (224 samples)
1940-1949 1030.2 (291 samples)
1950-1959 1032.4 (220 samples)
1960-1968 1032.5 (12 samples)
2002/2005 1037.8 (71 samples)

The difference between Bitter and Mild is now at its smallest since the 1920's.

As I said before, these aren't precise scientific figures. But they do still tell us something. I just have to work out exactly what that is.

What is highlighted, is my lack of data for 1970-2000. Ironic, as this it was in the 1970's that beer gravities first became generally available. Once I get some of those into my table, I should have a pretty good idea of the trends in beer gravities from 1920 until the present. Won't that be groovy?

5 comments:

Mark Andersen said...

I have to admit that is kind of interesting. At a glance it looks like depressed economies of the 1930's and then WWII caused beer gravities to fall. It makes sense. It's strange though how long it is taking them to come back up. With the rise in grain prices recently I wonder if the gravities will start falling again?

Jim Johanssen said...

Ron - It is nice to see the gravities increase, but will they get back up to their historic levels at 1900 or so.
Mark - I think the economic hardship must be much harder than present to cause wide spread gravity drop.
Cheers
Jim

Kristen England said...

I'm wondering how much it actually has to do with the buyers palate. This happend in the US during the 50's and into today. Slowly gravity went down. Seems like if you take just a bit away over the years you can lose 20 gravity points easily.

With the massive push towards 'sessionability' I'm wondering how long it will take for these beer to start dropping. However, maybe it will go the other way. 90% of the lineup being session. a brewery could really focus on making a bang up higher gravity beer. Who knows. The ingredient market is a bitch right now so we'll see.

Ron Pattinson said...

You shouldn't underestimate the enormous impact of WW II on Britain. Food rationing continued until the mid 1950's.

By the time brewers could brew as strong as they liked, drinkers had got used to weaker beers. After ten years or more, it's no real surprise.

Beer is a barometer of much else that is happening in a society. British session beers grew out of hardship and suffering.

You can't isolate beer from society, politics or economics. That's what makes it so revealing and so much fun.

Personally. I'd be happy if the British beer clock were reset to 1913. But that's not going to happen, is it.

The Czechs have mostly drunk session-strength beers since the 19th century. Now why is that?

Anonymous said...

This really is fascinating stuff - social history encapsulated in beer. I'll get to work on the 1993 Real Ale Drinker's Almanac to help you fill in the gaps. Don't hold your breath, though...