Wednesday 21 April 2010

Acidity in Porter

I do occasionally read other blogs. Zythophile's in particular. A post of his last week got me thinking. About acidity in Porter.

What train of thought did it wave goodbye to from the platform? Simple. That maybe I should take a look at the analyses I have. The ones that give acidity. So that's what I did. Just now. The results are intriguing. Now I just have to summon up the energy to tell you about them. It's Sunday and the Yorkshire puddings are already in the oven. I'll have to be quick.

First, an explanation about how I've selected these samples. It wasn't a complicated process. I just sorted on the acidity column. My beautiful table contains all the examples with an acidity of greater than 0.12%. (Most British beers in the 20th century had acidity of 0.04 to 0.06%.) An arbitrary cut-off point, mostly decided on to keep the table to a reasonable length.

For purposes of comparison, 3 analyses of Lambik in the late 19th century gave acidity percentages of 1.06, 1.11, 1.16.

Acidity of Porter and Stout
Year Brewer Country Beer Style Acidity FG OG Colour ABV attenuation
1929 Hammerton UK Oatmeal Stout Stout 0.12 1015.7 1049.4
4.36 68.22%
1929 Hoare UK Stout Stout 0.12 1010.9 1052.1
5.37 79.08%
1947 Raggett UK Stout Stout 0.12 1012.1 1040.4 1 + 18.5 3.67 70.05%
1948 Guinness Ireland Extra Stout Stout 0.12 1012 1047.2 1 + 6.5 4.57 74.58%
1948 Taylor Walker UK Nourishing Stout Stout 0.12 1008.4 1031.6 1 + 17.5 3.01 73.42%
1958 Guinness Ireland Foreign Extra Stout Stout 0.12 1015.9 1074.4 250 7.65 78.63%
1933 Barclay Perkins UK Stout Stout 0.13 1013.9 1052
4.95 73.27%
1940 Whitakers Halifax UK Milk Stout Stout 0.13 1021.7 1058.8 1 + 21 4.80 63.10%
1899 Unknown USA American Porter Porter 0.14 1011.43 1053.49
5.24 77.74%
1931 Hoare UK Stout Stout 0.14 1012.6 1054.2
5.41 76.75%
1951 JW Lees & Co Ltd UK Archer Stout Stout 0.14 1009.6 1041.7
4.17 76.98%
1953 Brickwoods UK Black Bricky Stout 0.14 1015.1 1045.7 1 + 12 3.96 66.96%
1887 Unknown UK English Stout Stout 0.15 1014.38 1074.72
7.66 79.63%
1950 Tennent Ltd UK Milk Stout (Export) Stout 0.16 1020 1063.2 1 + 17 5.60 68.35%
1950 Unknown UK Imperial Stout Stout 0.16 1017 1066.8 1 + 19 6.49 74.55%
1900 Unknown Canada Canadian Porter Porter 0.16 1015.57 1057.97
5.46 72.03%
1897 Unknown USA American Porter Porter 0.17 1026.36 1073.88
6.11 62.72%
1952 Leicester Brewing & Malting Co. UK Milk Stout Stout 0.17 1010.2 1044.2 1 + 15.5 4.42 76.92%
1955 Worthington UK Imperial Stout (White Shield) Stout 0.17 1017.3 1078.2 325 7.97 77.88%
1870 Hoare UK Porter Porter 0.18 1012.99 1052.42
5.13 75.22%
1870 Whitbread UK Porter Porter 0.18 1014.04 1054.11
5.21 74.05%
1953 Guinness Ireland Extra Stout Stout 0.18 1002.8 1046.3 1 + 8 5.70 93.95%
1879 Unknown, Dublin Ireland Dublin Single Stout Stout 0.22 1023.94 1061.75
6.15 59.82%
1870 Guinness Ireland Extra Stout Stout 0.24 1015.51 1078.06
8.20 80.13%
1870 Truman UK Porter Porter 0.24 1013.16 1051.33
4.96 74.36%
1901 Guinness Ireland Extra Foreign Stout, white label Stout 0.24 1013.20 1074.98
7.86 81.34%
1882 Unknown, Dublin Ireland Dublin Stout Stout 0.25 1028.38 1096.75
8.48 68.80%
1870 Berlin Germany Porter Porter 0.34 1020.7 1077.85 40 7.46 71.97%
1955 Bass UK Imperial Stout Stout 0.34 1018.4 1078.8 375 7.90 76.65%
1879 Unknown, Dublin Ireland Dublin Double Stout Stout 0.36 1011.24 1085.68
9.04 85.94%
1890 Haake & Co., Bremen Germany Porter Porter 0.45 1041.3 1089.3
6.18 53.75%
1884 Barclay Perkins UK Double Brown Stout Stout 0.46 1015.57 1077.45
7.50 78.70%
1950 Artois Brewery Belgium Extra Stout Stout 0.47 1018.1 1058 1 + 16.5 5.17 68.79%
1932 Guinness Ireland Extra Stout (bottled by John Martin, Antwerp) Stout 0.77 1014.4 1057
5.54 74.74%
Sources:
Whitbread Gravity Book
Wahl & Henius, pages 823-830
A dictionary of chemistry and the allied branches of other sciences, Volume 6 by Henry Watts, 1872, page 256
"Theory and Practice of the Preparation of Malt and the Fabrication of Beer" Julius E. Thausing, Anton Schwartz and A.H. Bauer, Philadelphia 1882, pages 748-751
"Handbuch der chemischen technologie" by Otto Dammer, Rudolf Kaiser, 1896, pages 696-697

Surprisingly, both the most acidic examples are from the 20th century. Guinness is well represented. Not such a surprise, given their production methods.

Dinner's ready. Do-it-yourself analysis time, I'm afraid.

9 comments:

Gary Gillman said...

Very interesting, and basically it suggests that stout and porter were considerably more acidic-tasting in the 1800's and well into the 1900's than for most beer in general in the 20th century. I would infer that porter and stout retained a traditional character in this respect, often resulting from retaining a vatted element (as for Guinness famously). The high numbers for Belgium in the 1900's perhaps can be explained by local taste since Belgium offered and still does numerous examples of very acidic beer.

When porter started reappearing after Michael Jackson's first books, I recall some fairly dry or astringent examples. Taddy Porter from Samuel Smith, as exported to North America, can still taste like that. Today, I would say most examples are fairly mild in 1800's terms.

Gary

John Keeling said...

As soon as we empty the next batch of wooden casks for Brewers Reserve,we will put some London Porter in and age it for 12 months.
We will see how the acidity develops

Ron Pattinson said...

John, great idea. Do you plan blending the Porter after the 12 months or selling it straight?

StuartP said...

On the subject of Porter, you can get one last look around the Park Royal brewery here:
http://www.forbidden-places.net/urban-exploration-park-royal-guinness-brewery#gal

My next brew is going be a soured porter, too. Followed by a shot at Lichtenhainer.
Am I easily led or what?
Amost forgot the WeissMild experiment.
So much brewing to do and so little time... when am I going to be able to develop my Plymouth White Ale?

Martyn Cornell said...

John, that sounds terrific - first time anyone has done that in London, I'd estimate for 70 years as a minimum: longer, if, as I suspect, London brewers never aged their porter much after the First World War.

Stuart P - let us know how you get on with making the Ripening!

Gary Gillman said...

Fantastic and I would only suggest with modesty (not being a brewer): consider hopping the beer very well, perhaps 3 lbs per barrel. I believe the benefits of long aging in wood will only manifest (for porter) with a very well-hopped brew.

Gary

Ed said...

How does percent acidity relate to pH?

Gary Gillman said...

StuartP: this should assist your Devonshire white ale project:

http://books.google.ca/books?id=Q1QDAAAAMAAJ&pg=PA188&dq=Devonshire+white+ale&cd=2#v=onepage&q=Devonshire%20white%20ale&f=false

Gary

Anonymous said...

hello there thanks for your grat post, as usual ((o: