Saturday, 13 February 2010

Brown Stout brewing the country way in 1763

My thanks to Gary Gillman for providing this one. A reasonably detailed description of Brown Stout brewing from the middle of the 18th century.

It's full of fascinating details:

- using soft pond water
- brewing in March
- no thermometer - mash temperature determined by seeing reflection in water.
- 100% brown malt
- multiple infusion mashes
- making mild beer from l;ater runnings
- the author can't spell the word "choose"

Here's the text:

"A Letter to the Editors, from a Gentleman in Hertfordshire, recommending his Method of brewing good Brown Beer, in some Counties called Brown-Stout.

I am one of those singular men, who love to keep up some remains of the old English hospitality in my house ; and for this particular purpose, I am never without a few hogsheads of good brown strong beer in my cellar, for the benefit, not of my own immediate family alone, but of such comers and goers as are worthy of it.

You must know, I have many years been particularly curious in the brewing of this beer, insomuch that, if I am well, I am generally copper-man myself, and superintend the boiling part.

I have taken a fancy to communicate my method in this operation to the public, and thought I could not hit upon an easier method of doing it, than by writing you the account in a letter.

If you find no inconsistencies, I hope inaccuracies will be overlooked.

I am very curious about the water I use, which is the softest I can get; and on this account I always take it from a clean neat pond, I have at the back of my house.

My time of brewing this beer is in March, which I reckon the best season ; therefore, in the beginning of that month, I make my preparations in the following manner.

The first thing I do is to take as much water as I shall want in all my brewings, (for I brew now for the whole year) and boil it in my copper. After it is boiled, it is put into large tubs for the purpose, and exposed to the air, to cool and purge itself for at least a week.

I then begin my first brewing, having previously procured a sufficient quantity of the best brown high-dried malt, which is ground three or four days before it is used, that it may have time to mellow and dispose itself for fermentation.

When a copper of water is heated so as to boil, about three quarters of a hogshead is laded into the mash-tub, and the copper immediately filled again, and made to boil. When the water in the mash is come to such a state that you may see your face in it, I have, by degrees, nine bushels of ground malt emptied out of the sack into it; this is to be well mashed, and stirred about with the rudder for near half an hour, till the malt is all thoroughly wetted, arid incorporated with the water: another bushel of malt is then lightly spread over the surface, and the whole being covered with the empty sacks to keep in the steam, it is left undisturbed for an hour.

At the end of the hour, the water in the copper being boiling, the fire is damped, and the water is left till you can see your face in it, after as much as is necessary is laded on to the mash, till the whole together will yield, when it runs off, a hogshead of wort; and this the workman is soon able to determine to a great nicety.

When this second quantity of water is laded on the mash, it is again well stirred and agitated, and being covered is kept quiet for another hour.

The first wort is then let out in a small stream into the under-back, and another hogshead of hot water is laded on the mash, which, after being well stirred with the rudder, is again covered, and suffered to rest for two hours.

In the mean time the first wort is returned into the copper, and six pounds of fine brown seedy hops are put into it, being first rubbed betwixt the hands. A brisk fire is then made under the copper, till the liquor boils, which is continued till the hops sink, after which the fire is damped, and the liquor strained into the coolers.

When it is come to be only as warm as milk from the cow, some yeast, or barm, is mixed with it, and it is left to work till all the surface appears in curls: it is then all stirred, and well mixed together with a hand-bowl, arid again left to work: this stirring with the bowl is repeated three times, after which it is tunned, and left to work in the hogshead : when it is nearly done working, the cask is filled up and bunged, but the vent-hole is left open.

When managed after this manner, the beer I am writing about will keep for years, but it will be good drink the succeeding harvest.

As to the second wort, which I mentioned above, it is set by for the next brewing, to be used in manner following.

For my second brewing, as far as wetting my mash, I proceed in the fame manner as at first ; but afterwards, instead of water, I heat the second wort of my first brewing, and lade it on my mash, the new wort by this means acquiring a very considerable addition of strength and softness.

The second wort of this second brewing I make with water, and save it to form the first wort of my third brewing, and so on for as many brewings as I chuse.

I must observe that I take off a third wort from my first brewing, which I heat, and lade on my mash of my second brewing, after taking off the second wort; and by this means, out of two brewings, I get, besides, a hogshead of very good mild beer.

I do not pretend that my method of brewing, above described, is better than any other ; but I am well convinced it is no bad way, as every body likes my beer, which, though high-coloured, is as clear as rock-water, and must be wholesome, as it is made of the pure and genuine malt and hops, without any other unwholesome mixture to adulterate it.

I shall be glad to see this account speedily inserted in your Museum Rusticum, and I may, perhaps, now and then send you a line or two, for I find, by your proposals, you would be glad of an extensive correspondence. I rest, for the present,
Your most obedient servant, Hoddesdon, Nov. 8, 1763."
“Museum rusticum et commerciale” 1763, pages 201 – 204.

The fun really does never end here at Shut up about Barclay Perkins.


Gary Gillman said...

Thanks for putting it up Ron and I've read this now many times and understand most of it I think.

Can his process be viewed as a kind of decoction mashing, in that the first mash (albeit all of it) is cooled and then raised to a higher temperature by the addition of the second copper of water?

How many pounds hops per barrel is he using, he mentions 6 pounds hops to a hogshead of wort, would that be about 3 pounds hops per barrel? Much less I think than was used in the 1800's for brown stout.

Is there any way to estimate the alcohol by volume of his resultant product?

What effect would there be to adding the yeast when the boiled wort was still milk-warm? In modern practice care is taken to make the wort cold I believe before yeast is added. Do you think his beer would have been partly sour in taste, either from this or leaving the bung out after the cleanse?

There is a kind of wry note to the account that I find intriguing. For instance he refers to being a copper-man and this seems to suggest, together with his reference to superintending the boiling, that ensuring a proper boil is the most important part of brewing. Yet he describes all the other parts of the brewing process with equal care.

The reference to the keeping quality is odd too. First he says the beer will last years, then he says (in the same sentence) it will last at least until the next harvest (some 6 months or so). It is almost as if he is toying a bit with the reader, yet the earnest and technical description of brewing brown stout and mild beers seems otherwise authentic.

The returns process, noted earlier by Zythophile, would I think lend a solera-type quality to the beer, perhaps impart a certain consistency of taste. But I think too it would increase the chance of microbial infection. Assuming he was able to avoid this, he probably got a "house" character at least from the process.


Graham Wheeler said...

It does not seem to be much out of the ordinary for the day.

There are a couple of idiosyncrasies; the main one being using fairly strong return worts to increase the strength of the succeeding brew, rather than to reduce the wastage of extract which is the usual reason.

The other idiosyncrasy being boiling until the hops sink. It doesn't take long for the hops to become waterlogged and sink, which indicates a very short boil time.

I reckon this chap's mash was overcomplicated and relatively inefficient. He could probably have achieved the same thing in a much simpler matter.

I expect that the peg was left out of the vent only until the cask had finished working. He wouldn't have had any condition in the beer if he had done otherwise.

I am sure he meant, in his reference to keeping qualities, that the beer could be drunk within six months, not that it only lasted that long. Six months was probably on the short side too. This is long before the days of running beers that were expected to drop bright almost spontaneously. It would take many months for him to achieve the clarity he boasts of, particularly as he is using soft water and, apparently, a short boil time.

The idea that exposing water to air and sunlight purges and softens it is apparent; that myth lasted from Thomas Tyron's day well into the nineteenth century. At least all the wiggly things from his pond had a chance to die off and settle to the bottom of the casks.

Ron Pattinson said...

There were 9 bushels of malt, or 1.125 quarters. Assuming 54 lbs per quarter extract:

1.125 * 54 = 60.75

How the extract was divided over the two beers is trickier. assuming 35 pounds for the Stout and 25.75 for the Mild Ale I get the OG's to be:

Brown Stout: 1064.63
Mild Beer: 1046.17

Which would leave the Stout around 6% ABV.

rod said...

I thoroughly enjoyed reading this - thank you. Isn't -
"I do not pretend that my method of brewing, above described, is better than any other ; but I am well convinced it is no bad way, as every body likes my beer"
a charming 18th Century thing to say?

Gary Gillman said...

Thanks Ron and Graham for these elucidations, very helpful.

I found the account of some significance in that it shows (probably for the reasons Zythophile put forth, but still) that porter had spread into parts of the country and seems to have become indeed part of manor life, at least in this radius of London.

An English friend once told me 60 miles in England can be like 1000 miles and no doubt this was true of 20 miles in 1761.

Also, the account states use of brown malt only. So does Watkins book of about the same time and Watkins' account is fairly detailed too, but Watkins likes elderberry juice at least to drink your porter mild. Morrice in 1802 (but describing late 1700's porter-brewing) liked quassia and certain other additives plus he was using by then mixtures of grists (pale, amber and brown generally).

I haven't checked the various forms of Ellis lately but do not recall the descriptions being as detailed as in this account.

With this account, written clearly, avoiding additives and confirming use of diastatic brown malt only, it would be easy to replicate a 1760 porter and you would have a unique "country" version (or at least one manor house's form) with its particular use of returns, sterilized pond water, short boil, etc. All one would need to do is make some brown malt and find some coarse brown hops or something very close, that should be quite easy. And you wouldn't have to wait 6 months to drink it. Just add elderberry juice to the mild beer! But now you are in Watkins' territory.


Gary Gillman said...

Here are George Watkin's instructions for a porter-brewing (start at pg. 123). Despite the idiosyncratic reference to elderberry, this account is the best systematic 1700's account I know. I can't rule out that the Hertfordshire gentleman, writing only a year later, might have known of this book but even so there are enough particularities in or of the latter account to make it a valuable addition to the literature IMO.

Watkins ends up describing not just a small-scale brewing, but by his repeated comparisons and other references to large-scale porter brewing you get quite an exact sense of what the big firms did (especially aging and blending batches but also their selection of water and other materials). Once again I believe Town and Country Brewer offers a much more compressed account.

As one interested in the very few 1700's-era descriptions of flavour you will find in the books, Watkins is most valuable because he tells you, and insists indeed on the point of how old porter tasted: it tasted like mild porter with elderberry juice added. He advises therefore to do this for the mild article made on a small-scale. It is the only way, he says, to make porter similar to what the large concerns do.

This is something I will do myself if I can find elderberries or their juice. I wonder if our version of Sainsbury across the street has that...


Gary Gillman said...

One follow-up to Graham's observation about the short boil: this indeed is so in George Watkins' account (1760) too. Watkins advises to run the wort into a receiver in which a bag of bruised hops is inserted. In his general instructions (earlier in the book when speaking of the different stages of brewing), he states that after this infusion you boil but only "for a few minutes". He says the beer will be better for it and one will save on the cost of heating the water.

I wonder if this is an echo of the time when ale was not (apparently) boiled. Why would boil times have become so much longer later? Has anyone ever made a (revivalist) beer in this minimalist fashion? It sounds to me as if the intent was to avoid extraction of too much bitter quality. Watkins' brewing sounds perhaps intended only for immediate consumption, so perhaps the London breweries he kept adverting to did long boils to ensure proper vatting and staling. Yet the Hertfordshire gentleman intended his beer for long keeping, and he did evidently a very short boil. Watkins doesn't state his domestic porter can't be kept for months too if that is the intention.

Rather odd, isn't it? How could the beers keep for a year or more with such a minimal extraction of hops tannins and resins?

Perhaps the answer lies in the fact that they were bruised - by hand. No large brewery would do that, even then. But if you could mill (by stones) grain, why could you not crush hops in a similar way? That would seem cheaper than heating great amounts of water in expensive copper alembics to boil them in.

Maybe the final answer lies in the fact that the water had to be purified one way or another, by boiling. The Hertfordshire gentleman did exactly that, before he started mashing. So perhaps it was cheaper all around for the London brewers to boil with (unbruised) hops but with the downside of obtaining a more bitter infusion than was ideal from a palate standpoint - at least until people got used to the taste. But I want to know what the 1761 manor house porter tasted like. I need elderberry or 6 months, and I need smoked porter which eschews roasted barley or other unmalted grains, but I need the latter to have a very short boil.

I think someone will have to brew it purpose-made to get close.


Graham Wheeler said...

Gary Gillman said...
I found the account of some significance in that it shows (probably for the reasons Zythophile put forth, but still) that porter had spread into parts of the country and seems to have become indeed part of manor life, at least in this radius of London.

I would not regard this beer as a porter. It would have been little different to the brown beer that Queen Elizabeth 1st would have been drinking two-hundred years earlier. It is a stronger version of the beer that porter evolved from.

If you look at the list of "remnants", returns, bottoms, slops and stuff that Barclay were chucking into their entire (their stale), freely admitted to a House Of Commons committee in 1818 (which can be found in Booth), Barclay justifies this by stating that some of the remnants are brown stout "which is twenty shillings per barrel dearer than common beer." This implies that he considered that brown stout was superior stuff, and that he thought the quality of his Entire was improved by it, slops or not.

So a brown beer or a brown stout on its own is not a porter. In fact I am rapidly coming to the conclusion that 'entire' and 'porter' were not originally the same thing either. The big London brewers supplied both mild and entire. mild + entire = London porter. Without the blend it isn't porter. Whether that blend was performed in the pub or in the brewery before dispatch is immaterial. In Barclay's case in 1818 it was done at the pub.

Elderberries may give a port-like quality which some descriptions say were a characteristic of porter, but what went on in those porter vats was much more complex than that. I doubt if it came anywhere close.

Many formulations exist that attempt to imitate the qualities of porter, but the fact is that many country brewers either did not know how to make true porter or could not afford the investment required in casks or vats and the maturation of large volumes of entire for two years, with malt tax paid upfront. Imitations were attempted because of that.

Clearly porter must have had a uniquely different taste, judging by the sorts of stuff that was used to try to imitate it.

Anyway, there are two commercial elderberry stouts listed on beer advocate; one of them American. You might be able to try it for yourself.

Gary Gillman said...

Thanks, Graham, I'll be in the U.S. later in the year and will try to find those elderberry stouts. I wonder if their brewers picked up on the elderberry from a historical standpoint.

I think technically you are right that what he made was not a porter but the only thing that makes it not so is it is not an entire grist beer. And this comes down to length and strength only, which is always a relative thing. Ron calculated the ABV of the 1763 brown stout as 6%. That is well within the range for common porter. It is the aging process that made porter what it was (as you rightly note, but the Hertfordshire gentleman is talking precisely about that kind of beer). Brown stout qualified, it was pre-eminently an aged drink - thus simply strong porter.

The systematic blending of old and new beer likely came later, as an expedient to reduce the cost of aging huge amounts of porter a year and two, as Zythophile has shown in his writings. This brought matters back in a sense to where they started, with three threads and other pub mixtures some of which must have blended old and mild beers. I think Barclay was being a bit canny in that testimony be referring to an expensive article blended into the mild beer. It was probably not very palatable on its own and represented I think the batch blending to which Watkins also referred.

Was Ware-type brown malt being used before the 1700's? I thought this was not the case, and while a brown beer of a kind was known, I hadn't understood it had a smoky and acidic tang as would have characterized porter from the blown malts.


Gary Gillman said...

I forgot to say one other thing: the very short boil times might explain why seemingly large amounts of hops did not make the beers undrinkable. Even the 1763 beer seems to use twice the hops of a modern pale ale and some 1800's beers used twice that or more. Yet I suspect the Hertfordshire brown stout wasn't more bitter than a typical porter of today.

I haven't ever really focused on boil times in the 1800's books. But if they were even half as short as those of today, I would think that the beers' IBUs were much lower than we might calculate with an eye to modern boiling durations. The short boils might have been done not just for palate but with an eye to re-use of the hops in the beers made after.


Ron Pattinson said...

Graham, I don't understand why you don't count this as a Porter.

6 pounds per hogshead is 4 pounds per barrel. How many hops a 19th century Stout contained depended on its gravity. 4 pounds per barrel is perfectly reasonable. Whitbread's 1876 SS (OG 1081) had 3.95 pounds per barrel.

Mild Porter and Entire Porter were two different beasts. The latter was aged the former not. Yet both were called Porter. And Mild Porter was sold and consumed by itself. I've seen plenty of recommendations to brewers to blend themselves and not leave it to publicans, who were likely to take the opportunity to adulterate it.

I strongly disagree that Porter was necessarily a blend of aged and unaged beer. The whole point of the original Porter was that it was a brewery-aged beer. However, the exact nature of Porter depends on which period you're talking about.

The first Porters were given a few months ageing at the brewery. Later in the 18th century they switched over to only ageing some Porter and blending it with fresh Porter to give it the aged taste.

But by the 19th century Porter was increasingly drunk mild and by the end of the century only Stouts and export Porters were aged.

Getting back to the text in question, I read the author as saying the beer would be in drinking condition after about 6 months (the next harvest) but would last a couple of years. That makes much more sense than your interpretation. Hence the beer was aged.

It would be weird if it weren't. Private brewers weren't under the same pressures as commercial brewers to get a return on the time and money invested in a brew. Ageing beer for many years was common. It crops up just about whenever private brewing is mentioned.

It looks like a perfectly good Brown Stout recipe to me.

Graham Wheeler said...

Ron Pattinson said...
Graham, I don't understand why you don't count this as a Porter.

Because it isn't a porter. It is a bog-standard brown beer made from 100% brown malt, which was more or less the standard malt from time immemorial; using brewing techniques almost unchanged from time immemorial. If your prediction as to gravity is correct, then by 1763 standards it does not even qualify as a stout. Mary Queen of Scots would have been drinking the same stuff, only stouter, long before porter hit the world. Unless you subscribe to the myth that porter and stout were synonymous, there is nothing porter about it.

Brown malt in itself does not make a porter; 100% brown malt beers preceded porter by several centuries.

Ageing does not make a porter. Most beer was aged from time immemorial. Many aged beers existed long after the porter days too, but they were not called porters.

Strength does not make a porter; beers of all strengths both preceded and succeeded porter by centuries.

Colour does not make a porter.

The label stuck on it does not make a porter.

Any combination of all of the above will not make a porter.

We are now running out of options as to what could have made porter different to any other beer of the 1700s.

What makes a porter is producing a cheap, young, beer that drinks old. This was done by the processes of 'bringing forward' and 'hardening', which was accomplished by blending a proportion of an older, stale beer with mild.

mild + stale = porter.
No fortification, no port wine.
No blending, no porter.

Entire and stale were the same thing. Certainly was as far as B.P. were concerned.

The entire is more complicated inasmuch as it was stale rather than aged; it was deliberately pushed past its best to the point of high acidity and sourness. This would not have been typical of ordinary beers aged in the ordinary manner. "Hardening" is the process of making the beer more acidic. This is rather more than merely "bringing forward", which can apply to any vatted and blended beer. Indeed, Barclay's Entire of 1818 would have been virtually undrinkable on its own.

But by the 19th century Porter was increasingly drunk mild and by the end of the century only Stouts and export Porters were aged.

No it wasn't. Mild was drunk mild; porter was becoming redundant. There is no such thing as mild porter; it is a contradiction of terms. There is no such thing as entire porter either.

By the nineteenth century, milds were more palatable than previously and entire had moved a long way from those characteristics that were highly esteemed by Londoners due to the brewers mucking about with it. The whole point of blending went away, porter became redundant and mild, which was cheaper than the blend, took up the slack.

Besides publican's have proved themselves quite capable of adding their own slops.

It looks like a perfectly good Brown Stout recipe to me.
Yes, but that is all it is.

Ron Pattinson said...

Graham, of course Mild Porter existed. Read Accum.

I can see exactly the proportion of Keeping and Mild Porter that wasw brewed in the 19th century. It declined from maybe 30% in 1820 to just about nothing in 1880. But that wasn't the end of Porter. It continued for another 60 years.

Porter wasn't replaced by Mild. It gradually fell out of favour. Mild itself is a result of the same process that moved Porter to being almost always sold Mild. Drinkers lost their affection for the aged taste. By the start of WW I there were very few beers being vatted, whether Stock Ale, Old Ale or Porter.

I have so many references that use "Porter" to encompass both Porter and Stout and seen so many identical Porter and Stout recipes that the only possible conclusion is that they were different strength versions of the same thing.

I must say that your idea of there being a "true" Porter and later versions being "fake" a particularly unuseful form of historical analysis. Way too subjective and unlikely to teach us much about the evolution of British beer.

Gary Gillman said...

Mild porter was called porter (many accounts do so) because porter used blistered brown malts. Is there evidence of this particular form of malt before the 1700's? And even if there was, it was still one of the "porter's liquors" of London, clearly.

So was the strong brown version which often Combrune said was sold cloudy and (one can infer) too young. Porter emerged as an industrial product, as Poundage makes clear - one made by the common brewers. Some was aged by publicans or in wholesale cellars (copying the brewers I believe) but the innovation of porter really was to age it at the brewery. This mimiced the best practice of artisans but the brown stout of the latter was no less porter for that.

Porter equals an aged palate achieved by the brewers keeping high dried brown beer in wood for the proper time. Before they did that quality was chancy, you had to rely on the three threads blends to get the right taste (either in the pub or made by brewers possibly, i.e., ready made blends). The brewers remedied that by methodical aging of large stocks and the 1763 beer is a perfect example but at an artisan level.

Porter became again a mix of mild and stale when the breweries decided not to age very large amounts of brown beer on premises, and so it brought things back to the "porter's liquors" era. Zythophile describes the poem of about 1718 which referred to pubs "in porters' liquors skilled". This was the different strengths and ages of brown beer. The commercial brewers then improved the product most wanted to drink (1720-1800). It was all a form of porter though: mild porter, brown stout, the pub or brewery or wholesale blends of pre-1720/Harwood/Parsons/Thrale etc.


Graham Wheeler said...

Ron Pattinson said...
Graham, of course Mild Porter existed. Read Accum.

You could have chosen somebody a little less discredited than Accum. He would have been screwed to the wall if he had not done a bunk back to Germany to avoid prosecution. And that was not just for the books he nicked; half the food and brewing industry were after his libellous blood too. His publisher got sued instead, and that is on top of the publisher losing the £400 bail he put up for Accum. Some of Accum's writings on porter were nicked almost word-for-word out of Ree's Cyclopedia. Compare.

Ironically, if I could be sure of anybody agreeing with me, it would have been Accum.

Before anyone delves into unravelling the evolution of British beer, one needs a definition and a datum from which to start.

A good start would be to wonder what made that particular brown beer any different from all the other brown beers produced by just about every brewer in the country; in fact the bog-standard beer of the previous several hundred years was brown beer. What made porter (which was just a brown beer) any different from the brown beers sent from Burton to Russia in the 1700s, for example. What made London brown beer worthy of the name porter, but not Burton brown beer? Ageing is not the answer, because brown beers were still aged, often at the brewery.

The real answer is that porter was more of a process than a beer style. It was the process that made London brown beer into porter, not its grist, not its colour, not its age nor anything else. Just that little bit of jiggery-pokery that took place before consumption that considerably cheapened the end-product and considerably altered and improved the flavour of mild.

That is genealogy for you.

StringersBeer said...

"Chuse" would have been a perfectly acceptable spelling at the time wouldn't it? For instance, it's spelled that way in the US Constitution (1787).
And for that matter (archaic spellings abound) in "THE RIME OF THE ANCYENT MARINERE" (1798). Formally, "chuse" was still being used in the London Gazette in the 1820s, alongside the more modern "choose".

Gary Gillman said...

I find pages 130-133 of George Watkins book that I gave the link to (1760) very instructive. There he refers to adding stale beer to a butt of porter that is too mild as one way the large brewers attain a balanced, correct palate. Another way to attain desired palate he says is by combining the worts of successive mashes, referring evidently to entire grist brewing. And throughout, he stresses aging, up to two years, and use of high dried malt.

While mixing and blending was one part of the arsenal of large brewers, it was just one technique, not invariable according to this period writer.


Gary Gillman said...

Just one other thought for the hopper, reading Richardson this morning he stresses the distinction between ordinary brown malt and brown malt that is blown. The blown version is made he says according to the "Ware practice", and he states further that it renders 30% less extract than pale malt and ordinary brown malt only 5% less. He states that London has a predilection for Ware brown malt even though its produce is much less in this respect. Although he does not say so expressly, I infer that blown Ware malt was classic porter-malt and one in particular use in London.


Ron Pattinson said...

Gary, that would make a huge difference to the strength I calculated, if "ordinary" brown malt were being used.

Assuming an extract of around 70 brewers pounds per quarter, that would mean the Brown Stout was more likely in the 1080-1090 range.

Graham Wheeler said...

I would suggest that most brown malt was 'blown' simply because it was not dried sufficiently before kilning it in anger.

To digress to Pale Ale Malt, the stuff close to what we have today; this was kilned for a period of at least four days with a gradually increasing temperature so that the moisture was driven out of the kernel before the furnace was given full thrutch.

Furthermore the drying floor of pale ale malt kilns was raised to at least fourteen feet above the furnace so that it, and the malt, was well away from the direct radiated heat of the furnace so that mostly convected hot air passed through the malt.

With early kilns of the old-style pale, amber, and brown malt variety, the drying floor was nearly on top of the furnace, so much of the heat was radiated heat.

Furthermore these malts were 'dried' in matter of hours, while the kernel still contained a lot of moisture. The sudden application of heat caused this moisture to expand and swell out the grain to considerably greater than its normal size.

Therefore on a volumetric bushel basis the swollen grain occupies more space in the measuring vessel than slow-dried grain, or you get a smaller number of grains in a given volume.

On completion of kilning the grain was usually quenched, causing more expansion.

So on a volumetric basis you will obtain an unrealistically low apparent extract. On a weight basis, however, the reduction will be considerably less.

Of course it all depends upon kilning procedure, times and temperatures, which vary greatly from reference to reference (although temperature is rarely mentioned).

Then we have snapped malt (like popcorn) and 'porter malt'. Porter malt, I believe, is a synonym for snapped malt, but I am not entirely sure. On some kilns, those with cast-iron floor plates, a degree of snapping was inevitably, because the cast iron plates got bloody hot, and the first layer of malt 'snapped' as soon as it hit the floor.

The good old-time kilns had horse-hair mats as the floor and the malt did not snap.

It is impossible to tell nowadays, whether any particular kiln had cast-iron, tile, brass wire, or horsehair floors. Except,perhaps, for Ware, which mainly used horsehair, sometimes tile, and kilned over hornbeam.

Which was lucky for the Londoners, because they liked hornbeam.