Monday, 14 March 2016

Hops in 1944 (part two)

The term “preservative value” pops up quite often in British brewing literature from the middle of last century. But how was it calculated?

Funny you should ask, because the article handily explains it:

“The preservative value was obtained from the formula (a + B/3) x 10 and it is interesting to note that had it been calculated on the alpha resins alone, the decrease would have been much more apparent as the beta resins in each case show an increase on last year, unlike the alpha. The comparative values of one of the new varieties (Brewers Gold) as ascertained from different sources is given below Using the above method of calculation, the figure is 134, while utilising the formula of alpha X 10, the figure is 92. The whole question seems to depend on whether or not there is any preservative value in the beta resins. Incidentally, the new varieties tested are the only hops to show an increased preservative value on last year, the comparative figures being :—

1942 1943
P.V. (a + B/3) Brewers Gold 124 134
P.V. (a+B/3) Brewers Favourite 84 107

Among individual types, East Kents again showed the highest preservative value, while Worcesters were relatively much lower. It should be noted that all the above results were borne out by the physical examination. The comparative results for 1944 will be published when ascertained and they may give some indication of influence of weather on hops. So far this year's weather has been very like that of 1943, a mild winter, a long period of drought, the only difference being rains in June instead of May. There was, of course, frost in the latter month of this  year,  but this should not affect the crop.”
Journal of the Incorporated Brewers Guild 1944, page 146.

I wanted to check if beta acid is still reckoned to have some preservative value. So I flipped open Briggs’ “Brewing Science and Practice”. It might say something on that topic. But 20-odd pages of organic chemistry is too much for my poor old, addled brain. If you have the answer, let me know. That’s the problem with modern brewing text books: the science causes me mental meltdown. I’m much more comfortable with the simpler – if far dodgier – science of 19th-century brewers.

I’d be interested to know if they were determining hopping rates based on alpha and beta acid content during the war. It would have made sense. No point in wasting hops.

Demand for hops was high:

“BREWERS' requirements of the 1944 crop are given as 272,000  cwts. compared with 267,175 for 1943, a slight increase which is more than accounted for by the continued high rate of demand for beer.  As this demand is likely to continue for at least some time ahead, and having regard to our very limited stocks, it is to be hoped that the authorities, in making plans for the rehabilitation of Europe, not intend to hand over foreign breweries any considerable quantity of the 1944 crop, should the European hop areas prove to be out of cultivation.  It is unlikely that any long term export trade with Europe will develop after the war in English hops—even for  new  varieties. Foreign breweries will probably take our hops during the period when they can get no others, as France did in 1940. Once their own gardens come into cultivation again imports of hops into Britain are more likely than exports from it.”
Journal of the Incorporated Brewers Guild 1944, page 146.

A couple of million US servicemen made sure that there was a good demand for beer. As did the high wages paid during the war.

I love the phrase “the rehabilitation of Europe”. Remember that this article was written late in 1944 when the end of the war was in sight. And at the time they had no idea what had happened in the most important hop growing regions on the continent, Bavaria and Bohemia, both in the heart of Nazi territory. Clearly British brewers were going to hang onto all the hops they needed.

The author shows great prescience there. After the war, UK hop exports did increase initially. You can see that in these figures:

UK home-grown and imported hops 1938 - 1953
Year ended 31st Dec. Estimated Produce Imports: Less Re-Exports Exports: British Hops Consumption Years ended 30th Sept. following surplus hops
1938 257,000 45,287 12,580 286,716 2,991
1939 288,000 7,840 16,050 265,512 14,278
1940 270,500 14,675 26,830 251,354 6,991
1941 262,800 31 17,209 223,007 22,615
1942 261,900 2,963 30,673 231,689 2,501
1943 285,200 198 24,941 243,900 16,557
1944 253,900 0 26,525 244,822 -17,447
1945 282,900 574 32,337 226,197 24,940
1946 257,451 29,243 35,056 217,759 33,879
1947 289,908 7,716 31,661 231,470 34,493
1948 273,584 4,561 29,135 233,168 15,842
1949 250,406 900 42,301 232,979 -23,974
1950 368,313 269 84,027 229,106 55,449
1951 321,824 626 107,738 228,512 -13,800
1952 282,349 502 76,620 225,569 -19,338
1953 272,593 1,015 64,762 216,841 -7,995
1955 Brewers' Almanack, page 63.
1971 Brewers'Almanack, page 54

Note also that, with the exception of 1944, home production and a small volume of imports ensured there were always just about enough hops to meet brewers’ demands.

Though the bit about the UK importing continental hops post-war didn’t happen. The UK had made itself self-sufficient in hops and had little need for imports. About the only foreign hops that turn up in brewing records of this period are Saaz.

Next we’ll be looking at hop-growing in the US and new English hop varieties.

1 comment:

Rod said...

"I wanted to check if beta acid is still reckoned to have some preservative value"

Beta acid isn't normally taken into account in working out hopping rates in today's industry, probably because hops are use as fresh as possible (this has not always been the case, of course).
Fresh (ie unoxydised) beta acid resins (the lupulones) do not isomerise in the boil, and therefore contribute little.
Oxidised lupulones will isomerise, so if you're using oxydised hops (as maybe they were in WWII)they are worth taking into account. Your problem there, of course, is that the alpha acid resins (the humulones) stop being wort-soluble once the hops become you can't win.