Sunday, 25 January 2015

German brewing in the 1970’s – hops

Are you getting confused? I am. That’s what happens when you try to compose three long series simultaneously. Am I in 1930’s America or 1960’s Canada today? Neither. I’m back in 1970’s Germany.

Hops. Now there’s a topic that should attract some attention. People are obsessed with the things nowadays. That’s why I’m getting so interested in barley varieties. Which I really should write about, given the things I’ve discovered recently. Maybe next week.

“Table VIII gives the average analytical values for different German hop varieties, analysed by the method of Wöllmer. These hop varieties are used not only in German breweries but also in many foreign breweries. The well-known aroma-hops, Tettnang, Spalt, Hallertau middle-early and Hersbruck show contents of alpha-acids in the range 5.6-6.0%. The so-called bitter hops (hops with high resin content such as Brewers Gold, Northern Brewer and Record) have a-acids contents in the range 8.3-10.6 % and can be distinguished from the aroma hops by the ratio of a-acids to B-resins, which is lower than 1:1 for the bitter hops. The variety Record shows the same level of cohumulone content as aroma hops, whereas Northern Brewer and Brewers Gold give distinctly higher values. There is, however, no relation between the humulone contents of these varieties.

Table VIII also shows the essential oil contents of the different German hop varieties. The total oil content ranges between 0.88-1.15% in aroma hops and between 1.42-2.15% in bitter hops; in accordance with this, bitter hops contain more myrcene than aroma hops. The different hop varieties can also be distinguished according to their content of 2-methylbutyl-isobutyrate; this ranges between 1.76-1.97% in bitter-hops, whereas pure aroma hops contain only 0.05-0.56%. The high content of posthumulene-1 and posthumulene-2 is characteristic of the variety Hersbruck and is used to identify this variety.”
Journal of the Institute of Brewing, Volume 83, Issue 1, March-April 1977, page 73.

Now isn’t that handy – a way to determine if hops are aroma or bittering without looking at alpha-acid content. Just check the 2-methylbutyl-isobutyrate level.

Here’s the table:

TABLE VIII. Bittering Substances (Wollmer Method) a-acid and Essential Oil Composition for Different German Hop Varieties (1974 Crop).
Variety Tettnang Spalt Hallertau middle early Hersbruck late hop Record Northern Brewer Brewers Gold
Total resins 17.1 17.7 17.4 17.6 19.9 21.9 19.2
a-Acids (%) 5.8 6 5.6 5.7 9.3 10.6 8.3
B-Fraction (%) 9.7 9.5 9.4 9.7 8.5 8.2 8.3
a-Acid: B-fraction 1 : 1.66 1 : 1.58 1 : 1.68 1 : 1.70 1 : 0.91 1 : 0.77 1 : 1.00
a-Acid composition
Cohumulone (%) 22.5 18.1 19.3 19.9 25.5 42.9
Adhumulone (%) 17 15.7 15.2 19.5 15.6 15.9
Humulone (%) 60.5 65.4 65.5 60.5 58.3 4.11
Total oil (% DM) 0.87 0.88 1.15 1.01 1.8 2.12 1.42
Oil composition
Myrcene (%) 24.0 21.7 20.2 21.5 24.1 34.5 36.9
B-caryophyllene (%) 5.7 6.2 8.7 8.1 9.8 8 7.6
Farnesene (%) 11.4 11.2 + + + + +
Humulcne(%) 21.3 20.5 331 126 31.9 22.1 194
Posthumulene 1 (%) 1.53 1.66 1.35 7.9 0.86 0.94 1.79
Posthumulene 2 (%) 0.55 0.55 0.39 6.4 0.34 0.29 0.32
2-MethyIbutylisobutyrate(%) 0.05 0.06 0.56 0.44 1.76 1.82 1.97
Methyl-n-octyl-ketone (%) 0.28 0.57 0.3 0.15 0.11 0.11 0.03
Linalool (%) 0.65 0.51 0.6 0.53 0.25 0.27 0.28

You’ve probably noticed that all the hop varieties in the table are still kicking around today, unlike the barley varieties we saw earlier. Why is it that barley varieties come and go within a decade, but hop varieties hang around for centuries? Could it be connected with the more direct contact between hop growers and brewers? With barley, there’s the maltster inbetween. And, as I’ve discovered recently, barley varieties are bred with the farmer rather than the brewer in mind. The emphasis is on yield per acre rather than flavour or performance in the brewhouse.

The next paragraph is frustrating and quite handy at the same time:

“All these hop varieties are used in breweries but it is unfortunate that no exact information exists on the proportions of each variety that are used in the copper as cones or as powdered products or as extracts. It is believed that, calculating the quantities of hops on the basis of their a-acid contents, 35-40% of the hops needed in West Germany are used as hop cones or as hops ground in the brewery, that half of the rest is sold as commercial hop powder and half as extract. Since in the future the whirlpool will find a wider distribution in breweries, it is expected that more and more hop products will replace the use of hop cones. The average rates in Germany, expressed as g/hl a-acids in the wort, are relatively high, e.g.

Light lager beer  (11.5% Plato) = 6-8 g/hl
Export beer  (12.5% Plato) = 8-12 g/hl
Pilsener beer  (12.0% Plato) = 12-18 g/hl
'Altbier'  (12.0% Plato) = 12-16 g/hl
Journal of the Institute of Brewing, Volume 83, Issue 1, March-April 1977, pages 73 - 74.

So they’ve no idea how the hops were actually used. At least the author is honest. Then again, it does give hopping rates. Unfortunately in form I’ve no other statistics for.

Anyone who has looked closely at a modern German beer label will know how widely used hop oils are. Annoyingly widely, as they often leave a nasty, coarse bitterness which is perfect for ruining a delicate Lager. But everywhere in the world there’s been a move away from cone hops. Many modern breweries are physically unable to handle them.

That pilsener and Alt are the most heavily hopped is pretty obvious to anyone who has tasted German beer. I’d be very interested to see what hopping rates are like today. My guess would be that the rate for Pilsener has dropped considerably.

I’ve just discovered a wonderful table of all the world’s hop varieties in Briggs. I’ll doubtless be pestering you with that soon.

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