Shut up about Barclay Perkins - Bottling in 1901: maturation after bottling

Visit the Shut up about Barclay Perkins site

http://1.bp.blogspot.com/-f0wOK5dwDZ...Strong_Ale.jpg

What a week it's been. I've stubbed my toe twice on important discoveries. I think I might have cracked my big toe, they were so weighty

The first I didn't notice when I first read the article. It's just an innocuous little entry in a table. But it's confirmed a suspicion I've held for a while, but haven't been able to find any evidence to back up. What is it I've discovered? That SA malt stands for "Strong Ale" malt.

Having seen how SA malt was used - almost exclusively in Strong Ales - had made guessing the meaning a bit of a no-brainer. But it's still nice to have confirmation. What's really got me excited, it is finding some detail about the characteristics of SA malt. You can see it in this table:

Table I.
A. Malts.
	Pale ale.	Mild ale.	Strong ale.
Easily fermentable matter.	60.5	64	57
Difficultly „ „ .	16.5	16	17
Unfermentable „ .	23	20	26
B. Bottled Pale Ales.
	At bottling.	6 weeks old.	12 months old.
Fermented solids	60 = 77% of F.S.	65.0 = 80% of F.S.	69 = 87% of F.S.
Fermentable residue	18 = 45% of R.	13.5 = 39% of R.	10 = 32% of R.
Unfermentable „	22 = 55% of R.	21.5 = 61% of R.	21 = 68% of R.
C. Bottled Strong Ales.
	At bottling.	6 months old.	2 years old.
Fermented solids	55 = 73% of F.S.	60 = 79% of F.S.	62 = 80% of F.S.
Fermentable residue	20 = 44% of R.	16 = 40% of R.	15 = 40% of R.
Unfermentable „	25 = 56% of R.	24 = 60% of R.	23 = 60% of R.

F.S. = Fermentable solids. R. = Unfermented residue.
Journal of the Federated Institutes of Brewing, Volume 7, Issue 2, March-April 1901, page 194.

OK, the information is pretty limited. But it does tell us that SA malt contained more unfermentable material than mild ale malt or pale ale malt. That explains the high finishing gravities of KK and KKK then. K Ales often used SA malt as their base malt. What would be the modern equivalent, I wonder?

I was very surprised to see that mild ale malt contained more fermentable material than pale ale malt. I would have expected it to be the other way around.

The rest of the table is also damn interesting, because it highlights the different maturation periods of Pale Ale and Strong Ale.

"Table I places side by side analyses of pale and strong ales made at different periods: the gradual alteration in composition is very marked.

The time required to produce first-class bottled strong ale is in all cases very much more than for pale ales, and beers vary very much in this respect, but in the first place a strong ale should remain in the brewery cellar for not less than six months, and after removing to the bottling store will probably take a month or six weeks to get into fit condition for bottling. After bottling it may take fully six months more to properly condition, and care must be taken that the corks do not get dry.

It is, I am sorry to say, quite a rare thing to see a bottle of strong ale in perfect condition, and I think if more care were taken in this respect there would be a much greater demand for this, the finest product of the brewery.

As the best bottling stout is usually vatted and it is not required to be brilliant, the conditions of bottling are somewhat different, but I do not propose discussing this question."
Journal of the Federated Institutes of Brewing, Volume 7, Issue 2, March-April 1901, page 195.

I've explained before the lengthy process of producing a Stock Pale Ale, one which could take more than 12 months. It seems that it took even longer to make a properly-matured Strong Ale. The article seems to say that 12 months is the minimum time required to produce such a beer. Something which it sounds like most breweries couldn't be bothered or couldn't afford to do.

The analyses after different periods of ageing are fascinating. You can see that a considerable amount of fermentation went on after bottling and continued for a very long time. We can see just how much by doing a few calculations.

Assuming that the first number for fermented solids is the real attenuation, it's easy enough to work out how the gravity fell after bottling. For Pale Ale, I've assumed the classic 1065º gravity. For the Strong Ale I've been more specific, taking the OG from Whitbread and Barclay Perkins KKK of the period, both of which had an OG of 1087º. The first FG, 1027º, is very close to the racking gravity of Barclay Perkins KKK, which was 1026.3º.

Here are the results in a nice compact table:

	OG	FG	ABV	Apparent attenuation	real attenuation
Pale Ale at bottling	1065	1016.5	6.32	74.62%	60.14%
Pale Ale 6 weeks after bottling	1065	1013	6.79	80.00%	64.70%
Pale Ale 6 months after bottling	1065	1010	7.21	84.62%	68.63%
Strong Ale at Bottling	1087	1027	7.81	68.97%	55.07%
Strong Ale 6 months after bottling	1087	1022	8.50	74.71%	59.93%
Strong Ale 2 years after bottling	1087	1020	8.78	77.01%	61.89%

You can see that after bottling, the ABV of both beers rose by almost 1%.

This helps me understand much better the analyses of 19th century Pale Ale where the apparent attenuation is well over 80%. At racking time, it might well have been no more than 75%. It's a new insight into the long process of producing truly bottle-conditioned beers.

The fall in the unfermentable residue of the Strong Ale I can only attribute to one cause: the action of something other than Saccharomyces, probably Brettanomyces. Not really a surprise in a beer that had been left a long time maturing in wood.

I don't know whether you'll be delighted or driven to despair when I tell you that I've barely scratched the surface of this article yet.

More...