Tuesday, 1 March 2011

Adjuncts in WW II

Adjuncts. For some bizarre reason, a topic close to my heart. We're still with that fascinating article from "Wallenstein Laboratories Communications". A great source, if only because I've not seen anyone else use it.

I particularly like the way some of the measures forced on brewers balanced each other out. Gravities fell, but the amount of adjuncts was reduced.

"Wartime Adjuncts

Those breweries which previously had difficulties resulting from nitrogen deficiency have had their problems complicated by war conditions. This has been the case especially since the introduction of flaked barley and oats as part of the grist.  Prior to that, the effect of lowered gravities was often offset by reducing the proportion of malt adjuncts.

The perennial need for economy in shipping space for the purpose of bringing in food to England has led, among other things, to the use of barley flour in bread. One consequence of this was pressure, very strong pressure, from the Ministry of Food to get the brewing industry to replace 10 per cent of its barley with oats. Already flaked barley was being used by many brewers as a  wartime device. Actually the barley so flaked was usually of good malting quality and simply could not be malted because of labor difficulties. It probably also saved fuel. By the use of flaked barley as a malt substitute, the extract provided was over and above that available from the restricted supplies of malt and sugar. With the release of barley for other uses by the Food Ministry, flaked oats and not flaked barley were slated for future use, although malted oats are being preferred in a few cases.

Flaked barley and oats have been manufactured by a process involving crushing, wetting, cooking wet up to 300-500°F and finally drying. Neither the germs nor the husks are removed. The enzymes are destroyed, but the starch is only slightly gelatinized. Neither of the flaked materials has presented serious technical difficulties. For the most part brewings have been normal, the change-over from flaked barley to flaked oats being scarcely noticeable in the breweries which had been using the former. Perhaps the chief problem has been concerned with securing a proper mixture of malt and oats in the grist, and special devices have been introduced for this purpose. Grinding times have had to be increased. Some brewers use ordinary raw oats which must be finely ground for them in a flour mill. Careful mixing with the malt grist is still necessary. Since flaked or raw oats yield only about two-thirds as much extract as malt, almost 15 per cent is needed to replace 10 per cent of barley in the grist. Apart from this, flaked oats are more bulky than malt, so that brewers who have already been using their mash tuns to full capacity need an occasional extra brew in some cases.

One advantage which has resulted from the use of flaked oats is that the considerable quantity of husk contributed has improved and hastened drainage of the wort from the mash tun and has thereby compensated largely for the loss of the bold-husked California malts no longer available. Flaked barley is less serviceable in this respect. Very few, if any, British brewers use a mash filter, and the time taken to sparge and drain mash tuns is a serious item in the day's brewing, that with labor shortages and blackout difficulties.

As might be expected, the British infusion system of mashing with typical English malt results in bringing only one tenth or less of the nitrogen in flaked oats into solution. Troubles anticipated from the lack of yeast nutrients in present-day, low-gravity worts have been rendered even more likely by the substitution of oats for malt or flaked barley. There already have been reports of such troubles. A few brewers have complained that the draught beers do not fine (when isinglass finings are added to the beer in cask) so easily since the inclusion of the oats, while many others have been gratified to observe no difference. A slight change in flavor has been noted by most brewers when as much as 15 per cent of the grist is composed of oats. This change is usually described as a dryness or slight loss of character, but it is so small as to pass almost without comment in the trade.

British brewers use malts of diastatic power 25° to 45° Lintner, which must seem incredibly low to the American brewer. Nevertheless, these malts are able to digest the increased amounts of non-malted adjuncts such as these flaked materials. No doubt the steady improvement in English barley, resulting from research and judicious buying in the trade during the past twenty years or so, has helped. The crops of the 1938 and 1939 seasons were excellent, those of 1940 and 1941 not so good. The chief objection to the 1942 crop was the generally low extract obtained from the malts, yet the diastatic power of these malts was as a rule high. Perhaps this has helped the digestion of flaked oats and ground, unflaked oats this year. Of course, it is the alpha-amylase of the malt that is mainly concerned, and the Lintner values normally determined in Great Britain tell us little directly of this.
"Wallenstein Laboratories Communications, December 1943, Volume VI, number 19" pages 155 - 156.

The government were very keen to get brewers to use oats. Partly because of a bumper crop in 1942. Also, I suppose, because barley was easier to slip unnoticed into bread. I wonder if the flaked barley that makes up 20% of the grist of modern Guinness was of malting quality? Somehow I doubt it.

See there's another example of measures balancing each other out. The husks of oats made up for the loss of husky Californian malt in the grist. See, there's another reason for the use of malt made from foreign barley in British beers. The coarser husks helped mash-tun drainage. Using raw oats seems a bit weird. Especially as brewers couldn't grind it themselves to the required flour. And wouldn't flour be likely to cause a stuck mash?

We also learn of the effect of these substitutions on the finished beer. Dryness. I can understand that. But what does "slight loss of character" mean? Blander, less flavoursome? It's surprising how little impact 15% oats appear to have made. Though I know brewers weren't very keen on using oats. But they're a conservative bunch often, brewers. Perhaps it was just prejudice rather than real objections. It would be nice to have the opinion of ordinary drinkers on the effect of oats on their favourite. Maybe they were happy enough at having a beer at all to worry about any changes in flavour.


Oblivious said...

"I wonder if the flaked barley that makes up 20% of the grist of modern Guinness was of malting quality? Somehow I doubt it. "

They did and still do by raw barely of Irish farmers and do their own roasting, I suspect as a costing in sourcing the raw material themselves and removing the maltester in up to 30-40% of the grist

What do you think?

Ron Pattinson said...

Oblivious, do you think they do their own flaking, too.

Talking of Guinness and roasting, there's a text about Irish patent malt that I need to post.

Craig said...

I tasted the "Bitter!" 1943 Truman P2 that I made. It's grist included 91% pale malt, 6% flaked oats and 2% Invert No. 1. As I mention yesterday, I's very soft, bodywise, but a bit under-flavored malt wise. It's similar, too me, like a Heffeweizen, with more hop bite and less banana/clove. Perhaps that's what meant by saying a slight loss of character. The color is very pale 4 or 5 SRM and cloudy. It is definatly not what you'd think of as a special bitter or ESB. I was intrigued by the addition of oats in the recipe, which is why I chose to do that one (over the Whitbread options)

Oblivious said...

No hard evidence but if they are doing their own roasting it’s quite possible. Unless of course they do some form of cereal mash to gelatinise the unmalted starch and then progress with a regular mash, but I bet it come down to what is the most energy efficient method.

"A Bottle of Guinness Please" : The Colourful history of Guinness, may shed some light on the matter

Adrian Avgerinos said...

"slight loss of character"

Based in my experience, I'd hazard a guess the unmalted grains dilute the malty flavor of beer. I brewed a mild recently that used 18% oats and 25% dark sugar. Sounds neat, but it was one of the blandest beers I've ever made. It tasted like a dark generic "Euro" lager fermented with ale yeast.

Craig said...

On a related note, I just came across a pic of an America, ground crew of the 391st BG, 574th BS, out of out of Station 166, Matching Green, Essex.

A number of the crew, have ponyied up to a trailer (with their mess cups) and are partaking in a cask or two of something marked 25 7 X. I can't make ou what is stenciled above the numbers, but something that appears to start with and F.

I'll email you the pic, in a bit.

Craig said...

So the 1943 P2 has been in the bottle for four days. It's fully carbed and it is no longer under-flavored. It's Italian bready, and dry... very dry, still soft and pale . The hops are still there but it has a wonderful, yeasty, biscuit flavor, that is remarkable.

It is a meal in a glass. I was unsure about this one, but It seems to be growing on me!