What was the year of Oat Beer?

Find out in my short video. It's a fun story.

 

Youngs adjuncts and sugars in 1939

Moving on, let’s look at the rest of the grist. There’s not much in the way of adjuncts. There’s just the one, flaked oats. At least, I think it was flaked oats. The brewing record simply says “oats”, meaning that it could also have been in malted form. I’ve gone with flakes, simply because that was the more common form.

Not using adjuncts in their other beers is quite unusual. Though by no means unique. Whitbread, for example, also brewed adjunct-free. Most brewers, however, employed flaked maize. UK brewers’ favourite adjunct for most of the 20th century.

Every beer contains some malt extract. Presumably there to add extra enzymes. It was reasonably common in mid-20th-century recipes.

Two numbered invert sugars make an appearance. The lightest in colour, No. 1, is, logically enough, in the two Pale Ales. In a relatively large proportion of around 12%. Which would have helped to keep the colour nice and pale, as is appropriate for the style.

No. 3, on the other hand, appears in the Mild and Strong Ales. In a rather smaller amount, just 7% to 8%. Its purpose would be dual, to add both colour and flavour. There was even less in the Black Beers, a mere 5%.

Rather surprisingly, caramel doesn’t turn up in the Black Beers, only the Mild and Strong Ales. In both of the latter, the quantities are quite small. The purpose being colour correction.

The overall average of 12% is a bit below the national average of 16%. Only the two Pale Ales are close to that national figure. 

Youngs adjuncts and sugars in 1939
Beer	Style	flaked oat	malt extract	no. 1 sugar	no. 3 sugar	caramel	total sugar
A	Mild		3.30%		6.60%	0.96%	10.87%
X	Mild		2.21%		7.19%	0.97%	10.37%
PA	Pale Ale		3.23%	12.90%			16.13%
PAB	Pale Ale		2.86%	11.43%			14.29%
P	Porter	5.00%	5.00%		5.00%		10.00%
S	Stout	5.00%	5.00%		5.00%		10.00%
XXX	Strong Ale		2.68%		8.05%	0.75%	11.48%
XXXX	Strong Ale		2.68%		8.05%	0.75%	11.48%
	Average						11.83%
Source:
Young's brewing record held at Battersea Library, document number YO/RE/1/8.

 

A comparison of brewing adjuncts

I'm having so much fun researching the book I'm currently working on, "Free!". I'm at the happy phase where some sections are pretty much complete and I'm filling in blanks. Currently, it's the part on adjuncts that I'm polishing off. Hence this post.

Though I'm not going to post the book text. As I've said a few times recently I'm returning this blog to its roots. Of serving up bits of raw data before I cook them into finished book text.

We're going to compare three popular adjuncts: maize, rice and oats. And see which makes the most useful adjunct.

Of greatest importance is the starch content. Because that's what is converted into extract. You can see that is considerably higher in rice. Which is probably why, initially after 1880, rice was the most popular adjunct. Though, by 1900, most brewers had switched to cheaper maize.

Though maize also had a problem: the high oil content. Because of its horrible flavour, it needed to be removed before brewing.

"By the removal of the germ and husk the oil is almost taken away from the com. This oil is of a yellow colour, and on exposure to the atmosphere is liable to turn rancid; it has an unpleasant flavour, gives off a disagreeable odour, and is removed by special degenerating machines by means of revolving knives acting upon the germs and husks."
Thatcher, Frank, A Treatise of Practical Brewing and Malting (The Country Brewers' Gazette, London, 1907), page 257.

I'm surprised at how high the starch content of oats. Even higher than that of maize. Though the yield in extract was rather poor. Oats could be used to boost body due to their high content of albuminous matter. Around 10% oats in the grist filled out the body of Stouts nicely. 

A comparison of brewing adjuncts
	rice	maize	oats
Starch	79	55.1	56.1
Water	10.6	12.0	13.6
Oil	0.1	5.5	4.0
Cellulose..	0.2	13.2	1.0
Albuminoids	7.5	8.0	16.5
Carbohydrates ..	1.4	3.0	6.0
Ash	1.0	1.8	2.4
Loss	0.2	1.4	0.4
total	100	100	100
Source:
Thatcher, Frank, A Treatise of Practical Brewing and Malting (The Country Brewers' Gazette, London, 1907), pages 256 - 259.

Brewing ingredients in WW II

When the dust had settled at the end of WW I, things didn’t totally revert to the way they had been pre-war. UK brewing still wasn’t self-sufficient in raw materials, though it was less dependent than it had been. Not because UK production of materials had expanded, but because less beer was being brewed and it was of the lower gravity and hence required fewer ingredients.

Considerable quantities of barley continued to be imported, and all of the maize employed came from overseas. As well as considerable quantities of cane sugar. Between 1930 and 1938, on average, about 15% of the hops used in UK brewing were imported.

Difficulties in sea transport greatly limited – or entirely suppressed – the importation of most brewing materials. This wasn’t as big a problem as in WW I, as percentage of foreign ingredients in 1939 than it had been in 1914. But it still required brewers to adapt their grists.

The war made people do many things that they wouldn’t usually do. Brewing was no exception. Brewers being forced to use ingredients they wouldn’t usually have considered.

Flaked maize, for which there was no domestic source, was the first for the chop. Though, as it was only really used as a cheap substitute for malt, rather than for any inherent characteristics which had little impact on the character of the beer, replacing it wasn’t such a problem.   Several alternatives were employed at various points of the war: rice, oats and flaked barley.

Brewing materials 1938 - 1950 (%age)
year	malt	Un-malted corn	rice, maize, etc	sugar	hops per bulk barrel (lbs)	hops per standard barrel (lbs)	Hops per quarter (lbs)
1938	78.31%	0.12%	5.75%	15.82%	1.28	1.71	7.8
1939	78.35%	0.08%	5.82%	15.75%	1.25	1.67	7.61
1940	83.81%	0.07%	3.09%	13.03%	1.19	1.62	7.58
1941	86.90%	0.09%	1.95%	11.05%	1	1.43	6.68
1942	85.54%	0.41%	2.99%	11.06%	0.84	1.31	5.87
1943	79.34%	0.31%	9.55%	10.80%	0.87	1.39	6
1944	78.88%	1.06%	9.22%	10.83%	0.87	1.38	6.09
1945	75.63%	1.78%	9.65%	12.93%	0.86	1.36	5.96
1946	76.53%	1.06%	8.69%	13.73%	0.82	1.29	5.83
1947	80.37%	0.79%	5.22%	13.61%	0.81	1.37	6.22
1948	81.75%	0.60%	5.22%	12.42%	0.9	1.52	6.69
1949	82.94%	0.55%	4.61%	11.89%	0.98	1.61	7.15
1950	83.50%	0.52%	4.17%	11.81%	1.03	1.67	7.19
Source:
my calculation from figures in 1955 Brewers' Almanack, page 62
Notes:
assumes a quarter = 336 lbs

 

 

Oats in WW II

One of the oddities of UK brewing during WW II was the use of oats. In beers other than Oatmeal Stout, I mean. Though in those the quantity of oats was tiny - far too small to have any impact of the flavour of the beer.

In 1943, the government, wanting divert some barley into food production, ordered brewers to replace 10% of their barley with oats. At most breweries this would mean a reduction or total elimination of flaked barley. The quantity of malt used, however, wouldn't change.

"Flaked Oats
In September, 1941, the use of flaked barley was introduced by the Ministry of Food in order to conserve malt supplies, and a large proportion of the brewing trade has achieved a substantial use of this material. It has now become imperative that there should be a substantial reduction in the use of barley, whether flaked or malted, while maintaining the present level of output of beer. Supplies of flaked oats will be available from the present suppliers of flaked barley, and in most districts these supplies are already sufficient. A proportion of the barley crop is required for use in the loaf, and it has become necessary in the national interest to ask every brewer to take steps without delay to obtain delivery of flaked oats and to carry out experiments in order to ascertain the maximum proportion of this material that he can use. It is hoped that brewers will lose no time in putting the result of their experiments into effect. In some cases breweries are working to the full capacity of their mash tuns, and the greater bulk of oats, necessary to replace a given proportion of barley or malt, presents a difficulty. It may be possible to overcome this difficulty by using ground oats in place of flakes, and there is no reason why a brewer who can more conveniently use oats in this form and has the necessary facilities for grinding should not take his supplies in grain instead of in flakes. It should be said, however, that the malting of oats will not be permitted, as this would be uneconomic in malting labour having regard to the lower output of beer obtainable as compared with that from a corresponding quantity of barley malt."
The Brewing Trade Review, March 1943, page 63.

The yield from oats is significantly lower than that from barley Which you need more of it to produce a wort of the same gravity. Which could be a problem if you were already brewing with a full mash tun.

You can clearly see that in Whitbread's recipes from 1942 and 1943:

Whitbread beers in 1942 - 1943
Year	Beer	Style	OG	pale malt	choc. Malt	crystal malt	mild malt	PA malt	wheat malt	flaked barley	flaked oat
1942	XX	Mild	1029.1			12.02%	68.11%		2.00%	12.02%
1942	IPA	IPA	1032.4	53.50%		5.73%		27.71%		6.69%
1942	PA	Pale Ale	1040.0			3.30%		76.65%		9.07%
1942	XXXX	Strong Ale	1044.4		2.80%			79.44%		9.35%
1943	XX	Mild	1028.3	46.39%		10.31%	18.56%				17.53%
1943	IPA	IPA	1031.4			6.52%		82.61%			10.87%
1943	PA	Pale Ale	1039.2			4.97%		72.93%			13.26%
1943	XXXX	Strong Ale	1043.8		2.86%			71.43%			17.14%
Source:
Whitbread brewing records held at the London Metropolitan Archives, document numbers LMA/4453/D/01/109 and LMA/4453/D/01/110.

The quantity of oats was about 50% higher than that of flaked barley.

Using oats was a very temporary occurrence - 1943 only. The next year everyone reverted to using flaked barley. What it does do, is throw up some odd recipes for people like me.

Given how high the percentage of oats was - 17% in the case of Mild and Burton - there must have been some impact on the character of the beer. Surely some drinkers must have noticed?

How much tax did beer drinkers pay during WW II?

I'm sure you've often wondered how much beer drinkers contributed to the UK's finances during WW II. A shedload would be a reasonable guess.

I already had the figures, but was only prompted to add them up when I came across this little article:

"BEER DRINKERS HAVE PAID £2,000 MILLION TO COUNTRY'S REVENUE
During the ten war and post-war years 1939-48 Britain's beer-drinkers, contributed through excise duty alone nearly £2,000 millions towards the country's revenue. The precise figure was £1,989,631.848. This and other surprising facts are revealed by the just-published handbook, Brewers' Almanack.

Now, however, the beer revenue is dropping rapidly because of the slump in beer-drinking, and to-day's tax of ninepence on the average public bar pint is yielding no more than did the sevenpence pint tax of two years ago.

Hopes for a return to better beer are suggested by the facts that the home barley yield has increased from 17,840,000 cwt in 1939 to 29,260,000cwt, in 1947; the hop yield has risen from 288,000 to 300,000 cwt, the wartime use of flaked barley and oats as brewing substitute is no longer compulsory, and brewers are now free to revert to the full use of malt.

Recent evidence of diminish-ing returns from high taxation may presage cheaper beer."
Sunderland Daily Echo and Shipping Gazette - Wednesday 23 March 1949, page 4.

The number for WW II is obviously less than £2,000 million. Here are the full figures, plus some other numbers for fun:

UK beer output, tax and average OG 1939 - 1948
year	bulk barrels	Total Tax £	average OG
1939	24,674,992	62,370,034	1040.93
1940	25,366,782	75,157,022	1040.62
1941	26,203,803	133,450,205	1038.51
1942	29,860,798	157,254,430	1035.53
1943	29,296,672	209,584,343	1034.34
1944	30,478,289	263,170,703	1034.63
1945	31,332,852	278,876,870	1034.54
1946	32,650,200	295,305,369	1034.72
1947	29,261,398	250,350,829	1032.59
1948	30,408,634	264,112,043	1032.66
Total		1,989,631,848
Source:
1955 Brewers' Almanack, pages 50 & 80.

My numbers tally exactly with those in the article. Not surprising, as the source is the same.

Almost forgot, I promised to tell you how much tax was paid on beer during the war. It was £1,179,863,607. Which even today, after 75 years of inflation, is still an enormous sum.

Turning to another point made in the article, yes brewers no longer had to use oats and flaked barley. But that didn't mean they "reverted" to brewing all-malt. As most brewers had never worked that way. What really happened was that they went back to using flaked maize instead of flaked barley.

Note that the cheery article didn't mention that beer wasn't really getting any stronger. Though it was up minutely on its nadir, which was in 1947.

Adjuncts in WW II

Since the 1880 Free Mash Tun Act loosened up the rules to allow unmalted grains, UK brewers had been quite keen on using adjuncts. Not necessarily always for reasons of economy.

In certain styles of beer – Light Pale Ales, for example – a light body and pale colour were desired characteristics. The use of adjuncts and sugar were the only way to achieve the characteristics expected by drinkers.

In the immediate aftermath of the 1880 legislation, brewers experimented with a few different possibilities. Barclay Perkins, for example, at first went for flaked rice. Eventually, however, they settled on flaked maize, as most other brewers did. And, the difficult years of WW I excepted, brewers mostly stuck with maize right up until WW II.

The percentage of adjuncts employed varied according to the style and the brewery, but 10-15% was pretty typical. Some breweries never went down the adjunct route, except when compelled during the war years. Whitbread, for example, who only used malt and sugar.

During the war, the type of adjunct used varied, presumably dependent on the availability of supplies. The first change came pretty early, in spring 1940 when I can see in brewing records that flaked rice replaces flaked maize. Fullers, Tetley, Boddington. It can’t be a coincidence.

The next adjunct to appear is flaked barley, something that was unknown pre-war. It was make practical by a big increase in UK barley production during the war. Despite being of malting quality, some was flaked to save labour and energy.

Early in 1943, brewers were asked to use flaked oats rather than flaked barley, which, owing to the poor supply of grain, was needed for bread.  But that phase was brief and in the final years of the war flaked barley was king.

Fullers X Ale grists are pretty typical in the adjuncts employed at different phases of the war.

Fullers X Ale adjunct usage 1939 - 1946
year	flaked maize	flaked rice	grits	flaked barley	flaked oats
1939	14.78%
1940		9.72%	1.94%
1941				14.28%
1942				13.77%
1943				6.91%	7.54%
1944				14.82%
1945				15.10%
1946				14.55%
Source:
Fullers brewing records held at the brewery

As soon as everything got back to normal in the 1950s, brewers returned to their preferred adjunct, flaked maize.

Let’s Brew 1943 Barclay Perkins XX

You may be wondering why I’m publishing recipes just a year apart. Simple: a lot happened in 12 months during WW II.

A couple of factors prompted the government to compel brewers to use flaked oats. First, there was a bumper crop of oats in 1942. The second was a rather more threatening development.

"Early in 1943, when the shipping position became difficult owing to the intensified U boat activity, barley was required for use in bread, and brewers were asked to replace flaked barley by flaked oats, but there were some misgivings about its use on account of its high fat content. A series of investigations was carried out to prove its suitability in order to satisfy brewers that they could be used with safety; 10 per cent. was considered a safe maximum. Owing to its huskiness flaked oats had the advantage of improving drainage in the mash tun, although, owing to its bulkiness, those brewers working with a full mash tun found it to be a disadvantage. A bad oat harvest in the following year, however, caused its use in brewing to be discontinued. The Ministry of Food then suggested that flaked oats might be replaced by dried potatoes, the drying plants in beet sugar factories used for drying the exhausted beet slices being utilized for this purpose. Investigations carried out with potatoes dried in this manner, however, proved them to be quite unsuitable for use in brewing owing to the unpleasant flavour imparted to the beer, and as the anticipated surplus of potatoes did not materialize, flaked barley was again used to replace flaked oats, and has continued up to the present time."
Journal of the Institute of Brewing Volume 52, Issue 3, May-June, 1946, page 121.

If you remember, flaked barley was itself a replacement for flaked maize. The use of potatoes in brewing might sound revolting, but I’ve found 19th-century German recipes which included potatoes. No reason why you couldn’t use potatoes in brewing. They are full of starch after all.

No surprise then that this XX, which was brewed in October 1943, contains flaked oats. You’ll note, to just about the maximum safe amount of 10%. But the total percentage of oats was even higher because there was also almost 5% malted oats in the grist. I like to call this Oat Mild. Any chances of that catching on as a style?

The adjuncts are the main difference between this grist and the one from 1942. The percentages of amber and crystal malt, as well as No. 3 invert sugar, remain around the same. What I’ve listed as mild malt was actually partly SA malt. As I don’t think you’ll be able to find that, I’ve upped the mild malt amount.

As usual, it was primed like crazy, raising the OG by 4º to 1035.4º. Which is a bit more reasonable. If you want to simulate this, add some No. 2 invert at the end of primary fermentation.

1943 Barclay Perkins XX
mild malt	4.25 lb	60.89%
amber malt	0.67 lb	9.60%
crystal malt 60 L	0.50 lb	7.16%
flaked oats	0.75 lb	10.74%
malted oats	0.25 lb	3.58%
No. 3 invert sugar	0.50 lb	7.16%
caramel	0.06 lb	0.86%
Fuggles 105 mins	0.75 oz
Fuggles 60 mins	0.50 oz
Goldings 30 mins	0.50 oz
OG	1031.4
FG	1008
ABV	3.10
Apparent attenuation	74.52%
IBU	24
SRM	13
Mash at	150º F
Sparge at	165º F
Boil time	105 minutes
pitching temp	61º F
Yeast	Wyeast 1099 Whitbread Ale

Malted wheat and oats

Sorry about this. I never quite finished everything in "Brewing Theory and Practice" about grains. Just got distracted, as usual.

Though in a way it’s a good thing that I was delayed. Because I’ve since got my hands on more brewing records from the 1950’s. Where malts other than from barley do show up.

But I’ll let Jeffery talk first.

“Malted Wheat and Oats
In addition to malt made from various types of barley, both wheat and oats can be malted. The former is difficult to put through the process because the acrospire grows outside the skin of the grain, and thus has no protection. Consequently, the malting of wheat is not a proposition favoured by maltsters. But when properly malted and used in mild ales, it imparts a fullness of flavour to the beer and also provides valuable feeding properties for yeast.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, pages 132 - 133.

OK, I think I get that. Wheat is difficult to malt, but it fills out Mild Ales nicely. Let’s take a look at actual practice. Flowers, a later Whitbread victim, used wheat in some of their beers. In 1955 they brewed nine different beers of which four received some wheat. But it wasn’t in the Mild Ale or Brown Ale. It was in their bottled Pale Ales. The percentage was pretty small, just 3% or 4% of the grist.

Let’s try another brewery. Shepherd Neame, they also dabbled in wheat. And in 1956 they also brewed nine beers, four of which contained malt. Once again, Mild wasn’t one of them. The four were Abbey Ale (a Strong Ale), Double Brown, Brown Ale and Light Dinner Ale. Interestingly, all bottled beers again. The proportion in the grist was again below 5%.

In the 1960’s, Eldridge Pope had malt wheat flour in pretty well all their grists: Bitter, Old Ale, Mild Ale, Brown Ale and Strong Ale. Only Lager and Stout received none. And when they first brewed Hardy Ale in 1967, that too contained wheat malt flour. Quite a lot of it, at over 10% of the grist.

I can’t make any sense out of that. Two breweries seem to have used it just for bottled beers, the third for just about everything. In the case of the first two, my guess is that the main purpose of using wheat, especially given the small quantities, was head retention. At Eldridge Pope the amounts are too large for that to be the reason. In the case of Hardy Ale it may be to keep the colour pale.

Will malted oats make any more sense?

“Malted oats are used as a minor blend in the production of stout, whence comes the name 'oatmeal stout'. They certainly provide and add to the nourishing value of stout, and supply useful nutrition for yeast. Such nutrition is much needed when roasted and black malts are in use, as the latter are practically devoid of nutriment. Oat malts have an extremely low diastase, but as the proportion used is very small, this is of no great importance.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, page 133.

Let’s see if Jeffery is any more accurate in the use of malted oats. Shepherd Neame did, indeed, use it in an Oatmeal Stout. Though, because of the way they parti-gyled, that meant it also ended up in some of the PA, a Bitter. Again, it was about 4% of the grist.

When Maclay brought back their Oat Malt Stout in 1966, obviously the grist included malted oats. Maclay were pioneers of the style in the 1890’s and, just like the early versions, the grist in the 1960’s had a high percentage of oats, around 30%. Which was even more than in 1909, when it was 25%.

Whitbread brewed an Oatmeal Stout until 1950. In contained a tiny amount of malted oats, less than 1% of the grist. This was typical of London brewers who would use just a token amount of oats.

A little earlier than Jeffery, large quantities of malted oats were consumed by British brewers. But that was during WW II when they were forced to by the government after a bumper crop of oats one year. Brewers hated it and dropped it again as soon as they could.

Brewing in WW II (part five)

We're still on grains. But I promise we'll get onto a more exciting topic soon. Like hops. You young people love you your hops. Not like us boring old twats.

This is great. The article discusses the increased use of unmalted grains during the war. Why is that brilliant? Because I have some great numbers on brewing materials. Ones I've been saving until now.

"The use of flaked barley became general quite early in the war as a malt adjunct, and as no restriction was placed on its use it helped to increase output. It was found to be readily converted in the mash tun and, as time has proved, when not used in excess, has had no directly deleterious effect on the beers, although it was not used at first without some misgivings on the part of the brewer. It increases the bulk of the mash, however, and when output was of so much moment some brewers replaced it by finely ground barley without any noticeable difference (cf. J. L. Baker, ibid., 1942, 109). Although a small proportion of the nitrogen constituents of flaked barley are rendered soluble in the mash tun it contributes but little yeast feeding material to the wort and therefore acts as a diluent to that contributed by the malt. This was a drawback in those breweries whose average gravity was low, although it certainly helped to correct and reduce the difficulties consequent on the use of poor quality malts."
Journal of the Institute of Brewing Volume 52, Issue 3, May-June, 1946, page 121.

There were two reasons why the government was keen on using unmalted barley: it saved on both fuel and labour. You can see how the usage of adjuncts increased during the war years:

Brewing materials (cwt)
year	malt		unmalted corn		rice, maize, etc		sugar		total malt & adjuncts
1938	9,378,888	78.31%	14,194	0.12%	688,086	5.75%	1,894,773	15.82%	11,975,941
1939	9,884,803	78.35%	9,910	0.08%	734,771	5.82%	1,986,478	15.75%	12,615,962
1940	9,857,838	83.81%	7,912	0.07%	363,588	3.09%	1,532,776	13.03%	11,762,114
1941	10,988,413	86.90%	11,897	0.09%	246,757	1.95%	1,397,642	11.05%	12,644,709
1942	10,918,102	85.54%	52,646	0.41%	382,207	2.99%	1,411,422	11.06%	12,764,377
1943	10,287,322	79.34%	40,592	0.31%	1,238,183	9.55%	1,400,573	10.80%	12,966,670
1944	10,621,168	78.88%	143,183	1.06%	1,241,121	9.22%	1,458,647	10.83%	13,464,119
1945	10,435,212	75.63%	245,751	1.78%	1,332,032	9.65%	1,784,064	12.93%	13,797,059
1946	9,976,998	76.53%	137,750	1.06%	1,132,748	8.69%	1,790,021	13.73%	13,037,517
1947	9,454,253	80.37%	92,974	0.79%	614,335	5.22%	1,601,186	13.61%	11,762,748
Source:
Brewers' Almanack 1955, page 62.

By the 1944 and 1945, the proportion of unmalted adjuncts was around 10% of the total - about double what it had been in 1938. While sugar fell from around 15% of the total pre-war to 10%. While the amount of malt itself increased in the middle war years. By the look of it to compensate for a reduction in the amount of sugar available.

But brewers were later forced to use an even less popular ingredient: flaked oats

"Early in 1943, when the shipping position became difficult owing to the intensified U boat activity, barley was required for use in bread, and brewers were asked to replace flaked barley by flaked oats, but there were some misgivings about its use on account of its high fat content. A series of investigations was carried out to prove its suitability in order to satisfy brewers that they could be used with safety; 10 per cent, was considered a safe maximum. Owing to its huskiness flaked oats had the advantage of improving drainage in the mash tun, although, owing to its bulkiness, those brewers working with a full mash tun found it to be a disadvantage. A bad oat harvest in the following year, however, caused its use in brewing to be discontinued. The Ministry of Food then suggested that flaked oats might be replaced by dried potatoes, the drying plants in beet sugar factories used for drying the exhausted beet slices being utilized for this purpose. Investigations carried out with potatoes dried in this manner, however, proved them to be quite unsuitable for use in brewing owing to the unpleasant flavour imparted to the beer, and as the anticipated surplus of potatoes did not materialize, flaked barley was again used to replace flaked oats, and has continued up to the present time."
Journal of the Institute of Brewing Volume 52, Issue 3, May-June, 1946, page 121.

Potatoes have been used in brewing. I've published a 19th-century recipe for potato Broyhan. So it is possible. I wonder if the Broyhan also suffered from a nasty flavour?

It's easiest to see the move to unmalted grains at Whitbread, because before the war they used no adjuncts, only malt and sugar. The first sighting of flaked barley is on 10th October 1941 in a brew of XX Mild Ale*. Significantly, IPA and PA brewed a few days later contained none. On 28th May 1942, in addition to flaked barley, barley meal and flaked rye is in the grists**. By now the adjuncts are in all Whitbread's beers.

In April 1943 flaked oats replaces all the other adjuncts***. The in February 1944 Whitbread switched back to using flaked barley****. You can see that Whitbread had little control over their grists but had adjunct them according to government policy and which raw materials were available.

Whitbread also occasionally used wheat malt. These tables should give a good impression of the decisions Whitbread had forced on them during the war years:

Whitbread Mild Ale 1938 - 1947
Date	Year	Beer	OG	FG	ABV	App. Atten-uation	lbs hops/ qtr	hops lb/brl	boil time (hours)	boil time (hours)	Pitch temp
25th Feb	1938	X	1035.3	1010.0	3.35	71.67%	7.44	1.11	1.25	1.25	65º
26th Sep	1939	X	1033.9	1010.5	3.10	69.03%	8.27	1.11	1.25	1	65º
25th Apr	1940	X	1033.5	1008.5	3.31	74.63%	8.12	1.12	1.25	1	65º
20th Nov	1940	XX	1031.1	1010.0	2.79	67.85%	8.42	1.07	1.17	0.75	66º
10th Oct	1941	XX	1031.2	1009.0	2.94	71.15%	6.38	0.76	1.25	1.25	65º
30th Jan	1942	XX	1029.1	1007.5	2.86	74.23%	5.84	0.75	1	1	65º
30th May	1942	XX	1028.4	1007.0	2.83	75.35%	6.19	0.75	1	1	65º
5th Apr	1943	XX	1027.8	1008.0	2.62	71.22%	6.07	0.76	1	1.25	65º
22nd Feb	1944	XX	1028.5	1009.0	2.58	68.42%	5.79	0.69	1	0.75	65º
4th Apr	1945	XX	1028.2	1009.0	2.54	68.09%	5.63	0.70	1	0.75	65º
12th Sep	1946	XX	1027.3	1008.0	2.55	70.70%	6.02	0.71	1	1	65º
3rd Jan	1947	XX	1027.5	1005.5	2.91	80.00%	6.02	0.68	1	0.75	65º
Sources:
Whitbread brewing records held at the London Metropolitan Archives, document numbers LMA/4453/D/01/105, LMA/4453/D/01/107, LMA/4453/D/01/108, LMA/4453/D/01/109, LMA/4453/D/01/110, LMA/4453/D/01/111, LMA/4453/D/01/112, LMA/4453/D/01/114.

Whitbread Mild Ale grists 1938 - 1947
Date	Year	Beer	OG	pale malt	crystal malt	MA malt	PA malt	no. 3 sugar	other sugar	wheat malt	flaked barley	barley meal	flaked rye	flaked oat
25th Feb	1938	X	1035.3	72.97%	12.46%			13.05%	1.52%
26th Sep	1939	X	1033.9	75.73%	13.59%			9.06%	1.62%
25th Apr	1940	X	1033.5	24.30%	13.08%	54.21%		4.98%	1.56%	1.87%
20th Nov	1940	XX	1031.1	81.42%	11.63%				6.95%
10th Oct	1941	XX	1031.2	65.39%	11.98%	4.99%	4.99%		5.66%	2.00%	4.99%
30th Jan	1942	XX	1029.1		12.02%	68.11%		4.01%	1.84%	2.00%	12.02%
30th May	1942	XX	1028.4	46.32%	12.63%	16.84%		5.61%	1.75%	2.11%	8.42%	1.05%	5.26%
5th Apr	1943	XX	1027.8	9.28%	10.31%	55.67%		5.50%	1.72%					17.53%
22nd Feb	1944	XX	1028.5		10.45%	71.08%		4.18%	1.74%		12.54%
4th Apr	1945	XX	1028.2		7.38%	62.21%		9.84%	3.70%		16.87%
12th Sep	1946	XX	1027.3		7.85%	75.14%		10.47%	2.06%		4.49%
3rd Jan	1947	XX	1027.5		7.79%	81.26%		8.91%	2.04%
Sources:
Whitbread brewing records held at the London Metropolitan Archives, document numbers LMA/4453/D/01/105, LMA/4453/D/01/107, LMA/4453/D/01/108, LMA/4453/D/01/109, LMA/4453/D/01/110, LMA/4453/D/01/111, LMA/4453/D/01/112, LMA/4453/D/01/114.

There's only one constant in the grist: crystal malt. Not even mild malt and No. 3 invert sugar, staples of Dark Mild brewing, appear in every beer. When things were starting to get back to normal in 1947, Whitbread reverted to a grist of base malt, crystal malt and sugar.

Next time the excitement begins. We'll be looking at hops.







* Whitbread brewing record held at the London Metropolitan Archives, document number LMA/4453/D/01/108.
** Whitbread brewing record held at the London Metropolitan Archives, document number LMA/4453/D/01/109.
*** Whitbread brewing record held at the London Metropolitan Archives, document number LMA/4453/D/01/110.
**** Whitbread brewing record held at the London Metropolitan Archives, document number LMA/4453/D/01/111.