Truman (Burton) malts in 1946

That the three Mild Ales all have basically the same recipe shouldn’t be a surprise. They were parti-gyled together. Nothing odd there. XXX, the Strong Ale, was sometimes parti-gyled with the Milds, too. Then other times parti-gyled with P2 Pale Ale. Which is a bit strange, As the recipes of the Mild and Pale Ale parti-gyles were different. The most obvious being the lack of crystal malt in the Pale Ales.

In the case of the Milds, the percentage of malt in the grist is lower than the 85% or so of 1939. Though for the Pale Ales and the Burton Ale, it’s a little higher than pre-war.

In terms of the types of malt used, nothing changed between 1939 and 1946, save for the addition of a tint quantity of black malt. I suspect it was adopted as a replacement, or partial replacement, for caramel.

I.M. Co – at least that’s what I think it says. The handwriting in Truman’s logs is terrible. My guess is that it’s some sort of patented enzymic malt. From where it’s listed in the brewing record, I’m pretty sure it’s not simply another type of pale malt.

Truman (Burton) malts in 1946
Beer	Style	OG	pale malt	black malt	high dried malt	crystal malt	I.M. Co.	Total malt
X	Mild	1025.8	45.90%	0.55%	22.95%	7.06%		76.46%
XX	Mild	1028.8	48.70%	0.57%	22.83%	6.09%		78.19%
No. 7	Mild	1033	46.23%	0.48%	23.11%	7.70%		77.53%
P2	Pale Ale	1040.7	70.34%	0.24%	12.79%		3.84%	87.21%
P1	Pale Ale	1047.6	70.34%	0.24%	12.79%		3.84%	87.21%
P1 Bott	Pale Ale	1050.7	71.14%	0.26%	14.65%		4.18%	90.24%
XXX	Strong Ale	1039.6	63.36%	0.32%	17.74%		2.53%	83.95%
Source:
Truman brewing record held at the London Metropolitan Archives, document number B/THB/C/354.

Bottling in 1901 - fermentability of the wort

You'll be happy to hear that we're on the home stretch. Just a couple more posts and I'll be done with bottling in 1901 forever. And moving on to 1914. I've a fascinating article about chilled bottled beer from that date. Thene there's the stuff about American brewing that has details of bottling. So much more fun to come.

The title may have tipped you off about the topic of today's post: the changes in the fermentability of wort due to various factors in the process of malting and mashing. A fascinating suubject, I'm sure you'll agree. With lots of details about dextrin.

Lott starts by summarising these factors:

"In order to emphasise the importance of a careful consideration of the effect of:—

A. Kiln heats on Malt,
B. Initial heats in the Mash-tub, and
C. Thick and Thin Mashes,

I have given in Table II certain figures which I will ask you to consider for few minutes in connection with the production of the most
suitable ales for bottling purposes.

Table II.
A. Effects of Kiln Heat.
	Under cured. 160º F.	Pale cured. 180º F.	High dried. 225º F.
Extract = dry solids, per cent.	68.6	67.6	62.8
Total sugars	72.5	63.7	54.5
Dextrin	13	21.5	32
Inactive matter	14.5	14.8	13.5
	100	100	100
Ratio: Total sugars/Not sugar	2.6	1.7	1.2

B. Effects of Mash Heal on a given Sample of Malt.
	148° F.	152° F.	156º F.
Extract = dry solids, per cent.	75.3	74.8	74.6
Total sugars	86	80	74.6
Dextrin	2.7	9.9	15.6
Inactive matter	11.3	10.1	9.9
	100	100	100
Ratio: Total sugars/Not sugar	6.2	4	2.9

It is evident that the most marked result of the increase of curing heats is the increase of the unfermentable or slowly fermentable dextrin, and the proportionate decrease of the readily fermentable sugars, so that high-dried malts yield a less fermentable extract than low-dried ones. This is perhaps more evident in the figures given in Table Ia."
Journal of the Federated Institutes of Brewing, Volume 7, Issue 2, March-April 1901, pages 202 - 203.

I've found high-dried malt very elusive. Sometimes it appears to denote very highly-kilned malts such as brown or amber malt. At others, just a version of pale malt kilned at a higher temperature. You can see the difference in the sugar composition of standard pale malt and high-dried malt. Crucially, the dextrin content was about 50% higher in the latter. No surprise, then, that the wort from high-dried malt was less fermentable. Mashing at a higher temperature also increased the dextrin conrtent at the expense of easily-fermentable sugars.

It's easy to see why a Mild Ale brewed from high-dried malt and mashed at a relatively high temperature would have a higher terminal gravity than a Pale Ale brewed from standard malt and mashed low.

"Another experiment gave the diastatic activity of three samples of the same malt:—

A. Partly cured, i.e., 2nd day on kiln =     56.9 Lintner.
B. Pale dried at 80º =     33.5 Lintner.
C. High dried at 220° =     11.1 Lintner.

The characteristic flavour of high-dried malt is not the only important feature which analysis fails to emphasise; there are certain caramelisation products which have a marked effect on the palate fulness of ales brewed with high-dried malts not nearly so evident in pale-dried malts, and almost entirely absent in undercured malts. The initial heat of the mash when the water is first extracting the soluble part of the malt is of the greatest importance in determining the ultimate composition of the wort, as in the first place it is this temperature which decides the quality of the diastase first extracted, and in the second place the action of that diastase on the starch cells of the malt.

The figures given are very conclusive; again a higher temperature increases the proportion of dextrinous matter, decreases the readily fermentable matter, and at the same time the soluble inactive matter to a slight extent.
Journal of the Federated Institutes of Brewing, Volume 7, Issue 2, March-April 1901, pages 203 - 204.

This section is, for me, very important. It shows that high-dried malt was retained diastatic power. Is 11.1º Lintner enough to convert itself? I'm pretty sure it isn't. I think somewhere around 30º Lintner is needed. Which means high-dried malt couldn't be used as a base malt.

It sounds as if high-dried malt would add body to a beer in two ways. Firstly, there were the "caramelisation products" created during kilning at a high temperature. Then there was the higher dextrin content which, not being readily fermentable, would also add body. Again, this shouldn't come as any surprise.

Finally something I've never considered much: the consistency of the mash.

C. Effect of Lengths.
	Thick mash.	Thin mash.
Extract = dry solids, per cent.	64	64.5
Total sugars	81.8	75.2
Dextrin	4.8	9
Inactive matter	13.4	14.9
	100	100
Ratio: Total sugars/Not sugar	4.5	3

Journal of the Federated Institutes of Brewing, Volume 7, Issue 2, March-April 1901, page 202.

"The difference produced by increasing the proportion of water used in mashing is not so great as some brewers imagine, but the direction as shown in this extreme case, where double the volume of liquid is used in the thin mash, the initial being kept the same, is increased proportion of dextrin and decreased sugar."
Journal of the Federated Institutes of Brewing, Volume 7, Issue 2, March-April 1901, page 204.

As you can see, a very thin mash produced a wort with more dextrins. But, as Lott says, this is a very extreme example, and it's doubtful anyone adctually mashed so thin.

Next time we'll be looking at various example beers to see their composition in terms of fermentability. The we'll be done. I think.

Stout Brewing in the 1920's

Browsing old Brewers' Journals is a dangerous occupation. I keep finding more fascinating titbits. Often not of the kind I'd been looking for. Searching for Scottish stuff I stumbled on something on Stout. Too good to ignore, so here it is.

In the 1920's Porter and Stout was less important to London brewers than it had been for nearly 200 years. As you can tell from the introduction, younger brewers needed to be reminded of London's role as a centre of black beer production.

"Stout Brewing.

Although in the space of an "Occasional Note" it is not possible to deal very extensively with all the details of stout brewing, nevertheless we may give a Abort and concise series of hints which may prove useful to some of our younger readers. London happens to be a great porter and stout brewing centre, partly  due  to the soft type of water supply available. And the brewers of the metropolis have been no less famous for their black beers than have their confreres of Burton been noted for their sound pale ales. One variety of the article corresponds to an entire malt beverage, whilst an alternative carries various proportions and descriptions of sugar. The composition of the grist also varies very considerably. It was formerly the practice to make up a black beer grist from a mixture of pale, amber and brown malts, but now the Irish method of employing only pale and black (roasted or patent) malt very frequently obtains. Mixtures are still used, however, and below  are given several grists  made up of different proportions of pale and coloured malts:

Pale.	Amber.	Brown.	Black.
80%	-	12%	8%
69%	-	25%	6%
83%	-	-	17%
89%	-	-	11%
45%	25%	25%	5%
60%	-	40%	—
86.5%	12.5%	-	1%

When a very luscious drinking article is desired special sugars are used in the copper, and for priming the finished beer. With reference to the brewing itself, the mashing liquor for a stout brewing should always be boiled, ordinary salt being employed as the saline constituent to the extent of three-quarters of a pound per quarter, the material being intermixed with the mash, as this is being made. The mashing process in the majority of cases embraces a very moderate mash mixture initial of 148 deg. Fahr., quickly raised by underlets and sparging. In connection with fermentation, the attenuation is generally carried down to nearly a quarter of the original gravity of the collected wort. Home brewers fine the beer in bulk and rack a comparatively bright fluid, whereby they are able to employ a liberal quantity of special priming sugar and unfermented wort in the cask.

For Irish  stouts a somewhat different system is in vogue. In the preparation of these beers the black malt used is much less black than that commonly employed in England. The roasting is not carried further than suffices to produce a rich chocolate brown. The Irish brewers commonly use but two kinds of malt, the so-called "black" and "pale," the former, however, being really dark brown, and the latter frequently "pale" only by comparison, in fact it is often so highly dried as to be practically amber. Such malts are finely crushed separately, and used in the proportions of about 23 pounds of black to the quarter of pale for porter, and with a less proportion of black, say 20 pounds for stout. Where the pale malt is of the  highly dried character referred to, the wort produced, even with prolonged mashing, is sufficiently dextrinous to leave enough body in the beer after fermentation, whilst with a view to securing good condition, it is the custom to add to porter and stout, intended for the home trade, a small proportion of strong wort and old beer, at the time of racking. The strong wort, of a gravity of about 1080 deg., and free from yeast, is used in the proportion of about two and a half gallons to a hogshead, two gallons to a barrel, and one and a half gallons to a kilderkin; old beer is added at the rate of about two gallons per barrel. Kept a day or two in store, before going out, the result of this "worting," or "freshing" as it is sometimes called, is to bring the porter or stout into good condition, which, with fair draught, lasts to the end. The use of wort, in this way, though perhaps rather more troublesome than priming with sugar, solution, has distinct advantages where black beer is concerned, for wort being more favourable to yeast production than sugar alone, the result is better condition, whilst at the same time greater fulness is secured.
Brewers' Journal 1928, page 32."

Let's look at those grists first. A large number of different combinations of malts were used when brewing Stout. I've loads of examples from London. Not one matches the grists given in the articles. That doesn't have any examples of pale, amber, brown and black being used together, while I do. And, to make things more complicated, some used other types of mat than those four. Barclay Perkins tended to use MA (mild ale) malt and SA malt instead of pale. and a few breweries threw in some crystal. Take a look:

London Porter and Stout grists in the 1920's
Date	Year	Brewer	Beer	Style	OG	FG	ABV	App. Attenuation	lbs hops/ qtr	hops lb/brl
11th Apr	1929	Barclay Perkins	BBS Ex	Stout	1079.5	1028.0	6.81	64.78%	15.00	5.00
21st Jan	1929	Barclay Perkins	BS	Stout	1053.8	1020.0	4.46	62.79%	6.00	1.26
7th Jul	1928	Barclay Perkins	BS Exp	Stout	1071.6	1022.0	6.56	69.27%	14.00	4.29
9th Jul	1928	Barclay Perkins	IBS	Stout	1060.8	1020.0	5.40	67.12%	9.00	2.24
4th Oct	1928	Barclay Perkins	IBS Ex	Stout	1102.6	1039.0	8.41	61.98%	14.19	6.62
4th Oct	1928	Barclay Perkins	TT	Porter	1027.4	1009.0	2.43	67.15%	14.19	0.70
13th Feb	1924	Camden	S	Stout	1045.4	1012.2	4.40	73.17%	6.70	1.29
14th Nov	1922	Courage	Porter	Porter	1032.69	1008.86	3.15	72.88%	7.11	5.83
14th Nov	1922	Courage	Stout	Stout	1043.77	1011.63	4.25	73.42%	7.11	1.91
2nd Feb	1928	Whitbread	ES	Stout	1054.8	1019.0	4.73	65.32%	9.19	2.14
2nd Feb	1928	Whitbread	LOS	Stout	1054.8	1019.0	4.73	65.32%	9.19	2.14
27th Apr	1928	Whitbread	LS	Stout	1055.8	1020.0	4.73	64.15%	9.20	2.12
2nd Feb	1928	Whitbread	P	Porter	1028.3	1008.0	2.68	71.71%	9.19	1.10
27th Apr	1928	Whitbread	S	Stout	1055.8	1020.0	4.73	64.15%	9.20	2.12

Date	Year	Brewer	Beer	Style	pale malt	brown malt	black malt	amber malt	choc. Malt	crystal malt	MA malt	SA malt	roast barley
11th Apr	1929	Barclay Perkins	BBS Ex	Stout	37.20%	9.93%	9.10%	17.51%				26.26%
21st Jan	1929	Barclay Perkins	BS	Stout		4.85%		12.82%		9.62%	44.88%	16.03%	11.81%
7th Jul	1928	Barclay Perkins	BS Exp	Stout		8.23%	9.05%	17.41%				65.31%
9th Jul	1928	Barclay Perkins	IBS	Stout		13.54%		16.11%			28.65%	32.23%	9.47%
4th Oct	1928	Barclay Perkins	IBS Ex	Stout		14.66%	7.79%	14.54%				63.01%
4th Oct	1928	Barclay Perkins	TT	Porter		14.72%	7.36%	14.61%				63.30%
13th Feb	1924	Camden	S	Stout	86.39%		3.73%			9.87%
14th Nov	1922	Courage	Porter	Porter	84.11%	6.11%	9.78%
14th Nov	1922	Courage	Stout	Stout	84.11%	6.11%	9.78%
2nd Feb	1928	Whitbread	ES	Stout	82.20%	7.66%			10.13%
2nd Feb	1928	Whitbread	LOS	Stout	82.20%	7.66%			10.13%
27th Apr	1928	Whitbread	LS	Stout	82.20%	7.66%			10.13%
2nd Feb	1928	Whitbread	P	Porter	82.20%	7.66%			10.13%
27th Apr	1928	Whitbread	S	Stout	82.20%	7.66%			10.13%
Sources:
Courage brewing record held at the London Metropolitan Archives, document number ACC/2305/08/253
Barclay Perkins brewing record held at the London Metropolitan Archives, document number ACC/2305/1/614
Camden brewing record held at the London Metropolitan Archives, document number ACC/2305/9/5
Whitbread brewing record held at the London Metropolitan Archives, document number LMA/4453/D/09/121

A couple of notes. All these beers contained sugar, too. The percentages are for the malts only. I've assumed a quarter of black and brown malt to weigh 254 pounds, all other malts 336 pounds.

The stuff about salt confirms what I've seen in some brewing records. But the timing of the addition wasn't exactly the same. Barclay Perkins added 2 oz. per barrel to the mash, but also another 3 oz. per barrel in the copper. That's the equivalent of 4 and 6 oz. per quarter, so 10 oz in all. Which is slightly less than the 12 oz suggested in the article.

I found the description of Irish malts particularly intriguing. I already knew that Irish black malt was different from the English version, being not as dark and charred. But I hadn't realised that the pale malt was much darker. It sounds like the elusive "high-dried" malt. Something I've been trying to pin down for years.

I'm grateful that there are some more specific details about the Irish practice of "worting". It confirms that it's basically a form of priming, but with wort instead of a sugar solution. Two gallons per 36 gallon barrel is about 5.5%. Which means each barrel was 5.5% old beer, 5.5% wort and 89% fresh beer. Now wouldn't that be an exciting experiment for you homebrewers? Worting a Stout the Irish way.

One thing that doesn't get a mention is Barclay Perkins technique of boiling a couple of bushels of black with the wort in the copper. I've still never seen this mentioned in any technical literature. Was it unique to Barclay Perkins?

Plunkett Brothers malt

Here's another advert for Plunkett Brothers maltsters. It provides a little more information. Not much, but a little.

It's a couple of years earlier than the last one, from 1888.

This tells us that candied malt was patented in 1885. Useful to know, even if it tells us little about the nature of the malt itself.

But I was surprised at just how many odd malts they were offering for sale. Two types of amber brown malt. Roasted maize - I wonder what on earth that was used for? Golden finish malt - great name, but what the hell was it?

More questions. Many more than the answers so far.

To brew Porter in a Private Family (1773)

Here's another 18th century recipe suggested by Gary Gillman. This time for straight Porter. As it's early and detailed, I thought it worth posting.

Something to bear in mind: this is a description of private brewing. It doesn't necessarily reflect what commercial brewers were up to.

"To brew Porter in a Private Family.

Take eight bushels of porter-malt, or any other very high-dried brown malt. Let it be ground carefully, so as only to crack the grains, not to let out the flour. Lay it in a cool place two days and one night. Then set on a hogshead of soft water, and so much more as will allow for waste, according to the directions before given. This must be covered with a head of malt, to keep in the spirit; and, when it has once boiled up, the fire must be immediately damped, and about one third part of it must be let into the mash-tub. Then it is to stand till cool. It must be cooler than what is required in the common method of brewing ; and then the malt to be poured gradually in. While it is pouring in, it must be stirred very well about; and, when all is in, a person should work it still round and round, first one way and then another, for half an hour together ; but this must be done gently, not to bruise or break the malt. The water in the copper should be kept at a little more than the heat of that which is used for the mash in common brewing : and when the malt has been thus mashed a full half hour, there must be as much more let in as will make it in the whole something more than half the quantity of the water. This must all be very well stirred once together, and then covered with the malt that was left out for that purpose : it is then to be covered close up in the vessel to keep in the heat, and thus to stand two hours and a half.

Then bruise four pound of hops between the hands; and tie them up in a bag ; put them into the receiver or under-back, and let the wort run out upon them in a fine, small stream. When this is running, stir up the fire under the copper, and make the remaining water considerably hot ; then run it on upon the grains, when the other is nearly run off ; and, after stirring them well about, cover the mash-tub, and let them stand two hours more. Then run this second wort upon the first, with the hops still in it ; and let them standtill quite cold.

Then lay a cask a little above the bottom of the receiver; draw off the whole directfly, so as to leave the coarser that has settled behind; pour the wort into the copper, put in the hops With it ; and boil them about twenty minutes. Then let off the wort into the upper back or cooler ; in which let it stand till so cool that you can bear to put your hand in it : then draw it off (leaving again the sediment behind) into the other, or under cooler.

In this let it stand till only milkwarm, and then prepare for workings put into a bowl three pints of good and moderately thick yeast ; work this gently about with a little of the wort, and then put it into the tun, Let the wort out of the cooler run gradually into the tun, so as to blend with this, and to leave its own sediment behind.

Thus there will be the pure wort cleared by these several settlements, and well mixed with the yeast in the tun; then let it be close covered up, and gradually there will be seen to gather upon it a fine mantling head, which will thicken every hour, and at last rise in waves, and then in little curls, This is the perfection of its fermentation. The tun must be uncovered from time to time to look down into this; and when it has arrived at this head, which will usually be in about six and thirty hours, it will be time to have the cask quite ready. This fine head will soon begin to fall ; and then it must be drawn off into the cask, leaving again what settlement it has made in the tun.

A small quantity must be saved to fill up as it wastes in the working, and the full time allowed for this last fermentation in the barrel: then a little isinglass, dissolved as before directed, must be put into the cask, and a quart and half a pint of elder-berry. When these last ingredients are put in, the vessel is to be left with a little opening at the vent-hole two days, and then stopped up entirely. The rule for tapping is when it is fine : and that generally happens in about fifteen days. If it be then drank from the cask, it will be very bright, clear and pleasant, well-coloured, and of a good body. It will have all the flavour of porter; tho' not the sound and peculiar taste of what has been kept a considerable time in a large body ; which is the case with most of the porter that is drank at the famous houses in London.

The flavour which a mixture of elder-juice gives even in this small quantity, is truly that which we expect in fine old porter; and, what is very singular, it is of the same kind with that which porter gets by being, long kept in a large quantity. This must not appear wonderful ; for in chemistry, and even in the common affairs of life, we find the taste of peculiar things may be given to a mixture, by those which seems of a very different nature: in particular, the root of masterwort, with common fennel seed, gives its tincture the flavour of sassafras. Other instances might be given, which indeed are frequent, tho' they are not known. This may be sufficient.

The other great article of time, and Keeping in a body, is what a private family cannot have opportunity of doing ; and 'tis for that reason, and that only, the public brewed porter will always be superior. The brewers Of this liquor have, large caskS; in which it is kept two years and more : and in those it undergoes a last fermentation; which, as it is slight and slow, produces no other change than mellowing of the drink ; that, is a perfect mixture of the malt and hops: it lasts a long time, and consequently the effect is greater: in time, this last fermentation, perfect rest; and a cool air from good cellarage, produce a fineness and clean sound taste in this liquor ; which is what we admire and what is not to be found in any other; because the same degree of keeping in any other kind than a brown malt beer would soften it, but take off the spirit.

Another advantage the great brewers have, which private familie cannot, this is an opportunity of correcting the faults of one butt of their porter, by means of another. It is in this their great practice assists them ; and it does the fame in their brewing : for their judgment directs to mix and bring this to a proper taste and strength ; otherwise, to an unexperienced person, they would seem to do it wildly. Thus, in brewing porter, they make three and sometimes four mashes; strengthening; them with a little fresh malt, or running them as they call it a greater length, that is, making more beer from the same malt, according to their pleasure. These several worts they mix and make the whole of such a strength as experience shews them porter ought to have ; and this they work and barrel up accordingly.

In the same manner, if a butt of porter be too mild, they will throw into it a small quantity of some that is very strong and too stale ; first dissolving in it a little isinglass. This produces a new tho' slight fermentation ; and the liquor, in eighteen or twenty days, fines down, and has the expected flavour. These, and many such advantages, none but the public brewers can have: and therefore none but they can brew this beer in that degree of perfection. We do not propose the brewing it in private families in London. But the extent of this enquiry into its nature is, that those who prefer this to other malt-liquors, and live in places where it cannot conveniently be bought, may brew it for themselves ; and that such as may intend to erect public breweries for it, may proceed with regularity. The construction of those large brew-houses, where it is usually made, favours also greatly the excellence of the drink: and this is the third article of which it was proposed to treat in this enquiry."
"The complete English Brewer", by George Watkin, 1773, pages 123-133.

I'm so busy. Still working on Barclay Perkins water chemistry, amongst other things. As well as a couple of grander projects. I would tell you more, but I don't want to spoil the surprise.

Kilning ca 1905

Not Southby today, you lucky devils. This time its Baker from a couple of decades later. The topic is malting.

High-dried malt. I've been trying to get clear in my mind exactly what is was. Partly because those flipping Truman's Burton logs are full of the stuff. The text below makes it sound like something half-way between pale and amber malt. Though the way its use is described, it strikes me as perhaps being more like Mild Ale malt with maybe a touch more colour.

"KILNING

This most important operation is divided into two stages, drying and curing. During the curing the character of the product is finally determined. The drying is effected by passing large volumes of warm air through the layer of malt. A high temperature is avoided at first, otherwise the diastase would be crippled or destroyed, and the starch gelatinised. During the drying process the malt is frequently forked and turned over, so that a free passage of air may be ensured.

On the first day of kilning, the temperature does not exceed 95° to 100° F. During the second day this is slowly raised to 120° to 125°, the third day to 140° to 150°, the fourth day the malt is finished off at the desired temperature. This is allowed to fall gradually, and the malt is heaped up on the kiln. The time during which a malt is kept on the kiln varies according to the quantity; some maltsters dry and cure in forty-eight hours, but the majority take three or four days. The object in view is gradually to raise the temperature to a maximum, and maintain it for a length of time sufficient to enable the heat to penetrate to the centre of the individual corns. During the curing process the diastatic capacity is greatly restricted, the malt is rendered friable, and the flavour is developed.

Varieties of malt:—

Pale malt for pale ale brewing is finished off at a temperature of . . 180°-200° F.
High dried malt for mild ale and stouts 200°-225° F.
Amber malt for mild ale and stouts 225°-240° F.

Brown malt is dried off rapidly over a wood fire. It has a much higher colour than amber malt, and no diastatic capacity. Black or patent malt is malt which is roasted, so as to produce the maximum amount of colouring matter. Roasted barley is now largely used in place of black malt, as it is cheaper and in most cases gives equally satisfactory results.

In this country malt is cured by exposure to the products of combustion from the kiln furnace. Curing by indirect heat, viz. the products of combustion being excluded from actual contact with the malt, is not usual in the United Kingdom, but is practised more in Continental and American maltings. Probably the part played by the products of combustion in conferring flavour on the malt has been much exaggerated. Excellent beers have been obtained from malts cured by indirect heat."
Source: "The brewing industry" by Julian L. Baker, 1905, pages 27 - 28.

I haven't forgotten Southby. More to come from him. On malt and brewing water.