Dry-hopping

It's amusing that some modern drinkers believe that dry-hopping is one of craft beer's innovations. When, in fact, it's been practised or centuries.

Let's take a look at how the process worked in the late 19th century.

"It is usual to dry-hop the casks before filling, this preventing much frothing that would otherwise occur, although it necessitates a second topping over of beer, the dry hops absorbing a great deal of moisture. A certain amount of care is necessary in selecting hops for this purpose; they should be large, well matured, free from leaf, rich in condition, and of undoubted soundness, the twigs exhibiting the absence of mould, even when they are steeped in water, and the water examined microscopically."
"The Theory and Practice of Modern Brewing" by Frank Faulkner, 1888, page 227.

Obviously, you wouldn't use mouldy old hops or the purpose. That would just be asking for trouble.

Though it seems that not all brewers were keen on using whole hops, worrying about the clarity of their beer. Instead, they used lupulin.

"Some brewers object to the use of hops, saying that if beer becomes brisk, annoyance is experienced by the publican on account of minute fragments of flower or leaf floating about in the otherwise decently bright beer; but my own impression is, that if we investigate the exact composition of the so-called particles of hops, we shall find that instead of being so, the particles consist of conglomerated yeast cells. If brewers do experience such difficulty, it is quite easy to use a small quantity of lupulin for the purpose of hopping down, which they can procure for themselves by gently rubbing down the flower of hops upon a fine sieve."
"The Theory and Practice of Modern Brewing" by Frank Faulkner, 1888, pages 227-228.

Dr hops could produce cloudiness. Orr even turn a beer grey.

"Some little care is necessary in order to prevent cloudiness of beer through the over-use of new hops in cask, such variety yielding a very oleaginous extract for which no proper solvent exists in beer until ethereal products result from slow fermentation in cask.

I dare say most of my readers have noticed the peculiar grey shade that hangs upon heavily hopped pale beers during preliminary stages of storage, this seeming to be due to a larger quantity of oil existing than can be held in perfect solution by the small proportion of solid extract existing after fermentation; and this fact shows us that in spite of the strongly-marked antiseptic and protective agency of lupulin, or the condition of the hop-flower, in spite of the aid of hop-tannin, at the time of artificial fining it is undoubtedly a great mistake to over-hop running beers that are expected to be perfectly brilliant soon after being placed in the cellar of the publican; while it is just as necessary to heavily hop down stock and export beers that have to keep for prolonged periods of time."
"The Theory and Practice of Modern Brewing" by Frank Faulkner, 1888, page 228.

What a surprise. Running beers didn't need many dry hops. While beers to be stored a long time before sale needed loads.

Finally, some recommended dry-hopping rates:

"The quantity of hops usually employed for dry-hopping amounts to some 0.25lb. per barrel for beers of 20 to 22 grav.[1056-1061°], 0.5lb. from 22 to 26 [1061-1072°] , 0.75lb. to 1lb. for heavy beers ranking upwards from 27 [1072°]."
"The Theory and Practice of Modern Brewing" by Frank Faulkner, 1888, pages 228-229. 

Wasn't that fun? Not really, I suppose. At least for anyone other than me.

Tetley cask Bitter specifications (part seven)

If all has gone well, I should be on plane jetting back to Europe. Do I feel guilty about all my air travel? No. Because I've never owned a car. Other than flights, all my travel is my electric-proered vehicles. Or on foot.

We've got to the end of the Tetley's Bitter specification. And a few surprises have been left until now.

Obviously enough, the last phase of the process was post fermentation. Where there was still lots of interesting stuff going on. I don't want to spoil things too much by getting ahead of myself. But there were a surprising number of differences between the handling of cask Bitter and cask Mild. For no obvious reason. We'll see all of this in my next series of posts. Bet you can't wait for that.

One of the drums I keep beating like a deranged football fan is the influence of tax systems on beer. We'll be seeing a very good example of the crap brewers were encouraged to do by the particular way UK excise duty on beer was collected.

After that tease, here's the first table of fun.

16. ADDITIONS POST-FERMENTATION
Material	Rate	Type	Where Added
Priming	NONE
Acid	NONE
Hop Pellets	2 Pellets (1 oz per Brl)	North Down	In Cask
PFB	25%	Isohopcon	Racking Tank
Colour	As required reboil after 48 hours	Caramel AB (1045°)	Racking Tank
Finings	4pt/Brl	Penang Leaf	Cask
Sterilised Beer	7.5% Max	1031°	Racking Tank
Preservative	As S02 (ppm)	NaMs
	468 1 pt Brl	NaMs	Colour C.V.
	155 1/3 pt/Brl	(working Soln)	Sterilised Beer
Protesal	None
Lucilite	None
Polyclar At.	None
Source:
Tetley Beer and Malt Specifications, 1985, beer page 5.

I'll start with a big surprise right at the start of the table. Tetley Bitter wasn't primed. Which is odd for a low-gravity Bitter of this type, which was supposed to come into condition quickly. Which means they were relying on residual sugars in the beer for conditioning in the cask. 

The figure on the first page described as "Limit Atten," Is presumably the lowest the gravity the beer should attain after cask conditioning. The value is given as 1003.5º. Which would leave the apparent attenuation at 90% and the ABV 4.2%. Which is a good bit stronger than I would have expected.

I'm not surprised that it was dry hopped. The quantity is fairly small, but it is a pretty low-gravity Bitter. Handy that the hop variety is listed: North Down.

What PFB stands for might be a puzzle, I do know what Isohopcon was. A hop extract manufactured by Pauls & Whites Ltd of Reigate. As we saw early, this provided 25% of the bitterness.  It's interesting how late this was added. Only in the racking tank.

The caramel was added at the same stage. Interesting that the OG of the caramel is listed, but not its colour. I suppose that it didn't really matter as only a sufficient quantity was used to hit the colour standard.

Nothing exceptional about the finings, which you would expect to be added to the casks.

Next we see the effect of taxing beer based on what was in the fermenter before fermentation. Because sterilised beer is a posh way of saying ullage. This is presumably retumed beer which has been sterilised to stop it infecting the fresh beer. At least Tetley limited the amount to 7.5% maximum. Watney was merrily using 15% and more, depending on the beer.

Why did brewers use returned beer? Because it was tax-free. When beer was returned to the brewery as unsaleable, the excise duty on it was refunded. If a brewery reused it, there was no tax on it. When the system was changed in the 1990s to be based on the ABV of the beer when it left the brewery, that advantage disappeared. Tax was due on everything leaving the brewery, including any ullage which had been mixed in.

I was slightly surprised to see preservative added. Though some was added to the sterilised beer which does make sense.

One final table.

7. DRAUGHT BEER RACKING
a) Temperature (°F) (°C)	55 +-3 (12. 8)
b) Yeast Count (10>6 cells/ML)	0.5 +- 0.4
c) Dry Hop i) Rate	2 Pellets per brl. 1 oz/brl
ii) Type	North Down.
d) Fining (pt/brl)	4
e) Storage Time (Brewery)	3 days
(Depot)	14 days max.
f) RT residence time	6-48 hours
Source:
Tetley Beer and Malt Specifications, 1985, beer page 5.

This is mostly a repeat of earlier information. You can see that the casks were given a reasonable amount of time to condition: 3 days in the brewery and up to two weeks at the depot.

Why would it sit for up to two days in the racking tank? I'm guessing that was so they could blend together different batches.

Next up is cask Mild.

Rose dry hops in 1896

Unlike most brewers, Rose did bother to note down the dry hopping in their records. Though not always. In the case of the IPA, I’m sure they’ve just forgotten to write it down. Which is pretty annoying.

The preference for the flavour of German hops is clear in the choice of dry hops. Every beer, apart from the Stout, contains some Hallertau. While American hops appear in only the Stout. A style where delicate hop flavour would have to compete with a stack of roast. 

Rose dry hops in 1896
Beer	Style	dry hop 1	dry hop 2
M	Mild
X	Mild	Hallertau 1894
XX	Mild	Kent 1895	Hallertau 1894
XXX	Mild	Kent 1895	Hallertau 1894
XXXX	Mild	Hallertau 1895
B	Pale Ale	Kent	Hallertau
AK	Pale Ale	Kent 1894	Hallertau 1895
IPA	IPA
PA	Pale Ale	Kent 1895	Hallertau 1894
Stout	Stout	California 1894
Source:
Rose brewing record held at the North Yorkshire County Record Office, catalogue number ZDI.

Racking and Dry hopping 1880 - 1914

Time for another preview from my major book after next. Or something like that. I've a very good reason for posting this now. I've got a cold and can't be arsed to write anything new. Well, apart from this paragraph. But that doesn't really count, does it?

Racking
After fermentation had finished, the beer was left to settle for 24 hours either in the fermenting vessel or a settling back.

When the beer was bright, it was racked into trade casks. A rubber pipe, fitted with a metal nozzle was used to fill the casks. The nozzle's function was to ensure that the tube reached almost to the bottom of the cask so the beer didn't get too agitated and begin to froth over.  

Dry hopping
Before being filled with beer, a quantity of whole hops was added to the trade casks. Standard-strength beers received between 1 and 1.5 pounds per barrel, stronger beers more. The best quality hops were used, usually Goldings or Worcesters. Only whole flowers, free from disease of fungus, were suitable.  

Dry hopping was about a lot more than just adding flavour to beer. It also benefitted the secondary fermentation in the cask.

The volatile oils present in the hops added flavour and aroma to the beer. The hops also helped conditioning, as they contained a diastatic enzymes that broke down lower malto-dextrins into more fermentable sugars, which would be consumed by the yeast during secondary fermentation. By attracting suspended particles, the hops aided clarification, too.  

Why dry hop? (part three)

I'm continually amazed at what grabs my readers' attention and what doesn't. I thought that the article I've based these posts on was intrguing, but rather obscure. Something only of interest to a few professional brewers.

There isn't going to be much commentary from me this time. Partly because I'm not sure that I really understand it all. Partly because it's Easter and I've got better things to do.

"It must be remembered, in considering the results of this last experiment, that the influence of the yeast of the beer had been completely prevented by the chloroform, and that if the yeast had been still in possession of its functions, hydrolysis would have proceeded with even greater rapidity, as we know very well that under the combined action of organised ferments and diastase hydrolysis often goes on much more rapidly than under the influence of the diastase alone. As it seemed possible that the diastatic activity of hops might be due wholly or in part to the seed: which they generally contain, we have made comparative experiments with the hop strobiles, in one case including the seeds, and in the other after the seeds had been carefully picked out. We also append a determination of the diastatic activity of the foliage leaves of the hop plant. The results are calculated out for the amount of maltose produced from soluble starch by 10 grams of the material acting under standard conditions :—

(1) Hop-cones, including' seeds, 9.60 grams maltose. (2) Hop-cones, freed from seed, 2.06 grams maltose. (3) Foliage leaves of hop plant, 2.01 grams maltose.

The seeds doubtless contribute largely to the diastatic activity of hops, but the bracts of the strobiles, which are really leaf organs, have also a very marked hydrolytic effect,  yet an aqueous infusion of the same hops, no matter how concentrated it maybe, is incapable of producing any diastatic in fluence. We have already referred to the difficulty there is in extracting enzymes from some kinds of tissue, owing to the tenacity with which they are retained by the cell protoplasm, but it is very seldom indeed that an aqueous extract of such tissue, when properly prepared, is entirely without action, as is the case with the hop infusion. It therefOre seemed in the highest degree probable that there was something extracting from the hop which prevented the diastase going into solution. As we know that hops contain a considerable amount of tannin, and that tannin has a very great retarding influence on diastatic action, owing to its rendering insoluble that class of albuminoids to which diastase belongs, it seemed highly probable that the tannin of the hop was responsible for the abnormal results obtained with the aqueous infusion. Such was, in fact, found to be the case.

In the first place we found that an aqueous infusion of hop extracts less diastase from a given quantity of malt than does distilled water under similar conditions. This is shown by the following experiment :—

Two dilute malt extracts were prepared:

(1) By digesting 0.5 grams of finely divided malt with 100 c.c. of water for 48 hours.

(2) By digesting 0.5 grams of the same malt with 100 c.c. of water and 3.5 grams of hops for 48 hours.

On filtration the relative diastatic activity of these two extracts was determined. The relation was found to be as follows, No. I being taken at 100:—

(1) 100.0
(2) 16.1

We see that in (2) the addition of 3.5 grams of hops per 100 c.c. to the extraction water has reduced the diastatic activity of the resulting malt extract to about 1/6. That this remarkable result is due to the tannin of the hops prevent. ing the diastase going into solution was proved in the following manner :—

When an aqueous infusion of hops is shaken up for a short time with some raspings of untanned hide the tannin is completely removed from the infusion, but no other constituent of the hop extract is touched.

A strong aqueous extract of hops was prepared by digesting hops with a comparatively small quantity of water for 48 hours. The filtrate was divided into two parts, A and B.

A. 100 c.c. of the hop extract was digested with 1 gram of finely divided malt for 24 hours.

B. 100 c.c., treated in a similar manner, but the tannin was first removed by shaking with hide filings.

After standing on the malt in each case for twenty-four hours the dilute malt extracts so produced were filtered off, and
their diastatic power determined. This was measured by the amount of maltose hydrolysed from soluble starch by an equal volume of each extract, all the usual conditions being fulfilled. The following numbers show the amount of maltose produce by 100 cc. of the extracts :—

                     Diastatic Activity.
Infusion A    0.000 grams.
Infusion B    11.250 grams.

We see that in A the amount of tannin in the hop extract used had been sufficient entirely to prevent the dissolution of the diastase from 1 gram of malt; whilst in B, which differed from A merely in having had its tannin removed with hide filings, the diastase had readily gone into solution.

We are now in a position to understand how it is that it is impossible to prepare an infusion of hops showing diastatic activity, although the hop-strobile contains a very notable quantity of diastase, which is brought into action when the hops themselves are immersed in the liquid containing a hydrolysable substance.

The tannin is contained for the most part in special cells of the leaf-tissue, and, under ordinary circumstances, does not come in contact with the diastase, which exists to a greater or less amount in the general starch-containing parenchyma. When, however, the dried leaf-issue is treated with a comparatively small amount of water, the solution of the tannin is sufficiently concentrated to prevent the diastase entering into solution. When, on the other hand, the hops are immersed in a comparatively large amount of liquid, the tannin, which diffuses first in point of time, forms such an extremely dilute solution that it has but little or no effect upon the diastase which difluses into the liquid at a much slower rate. There is another reason, also, in the case of beer why the tannin of the hopping-down hop does not arrest diastatic action. Unless beer has been very highly hopped indeed in the copper, it always contains, after the fermentation is finished, a sufficient quantity of albuminoids of the right kind to precipitate tannin from solution. This is doubtless the fate of the tannin of the hop used in dry-hopping; it is quickly removed from the sphere of action, and cannot consequently exert the least inhibitory action on the “freshening” power of the hop. In considering the results which we have recorded in this paper - results which, we think, have given a complete explanation of the influence of dry-hopping on the after fermentation of beer - no doubt certain practical questions will suggest themselves to you; and, of these, perhaps the one of greatest importance, is the bearing these experiments have on the method of curing the hops at the time they are picked. It is not long ago since we had an authoritative statement from a gentleman closely connected with hop growing, that the temperatures employed in drying on the oasts are much too low, and that hops will keep very much better if dried at a higher temperature. We do not dispute the accuracy of this statement but we must give a word of warning to hop growers who carry out this suggestion, that they will run very great risk of destroying in the hops one of those qualities which is essential to the production of a suitable article for dry-hopping."
The Brewers' Guardian 1893, pages 107 - 108.

I had no idea that tannin prevented distase from going into soultion. So does that mean that too ,amny hops in the mash tun could bugger up conversion? Or am I getting this totally wrong?

Be happy to hear the thoughts of anyone who understands this better than me.

Why dry hop? (part two)

I hadn't forgotten about this. Just been resting my brain a bit.

Not that I'll be getting through all of the second instalment of the article this time. For some reason part two of the article ios three times the length of part one. A bit strange.

The theory that wild yeasts on the hops were responsible for secondary fermentation is given short shrift. And with good reason. Stuff like Brettanomyces takes a while to get going. Longer than it takes a secondary fermentation to kick off.

"WE are now in position to ascertain how far the sugars of the hop are accountable for the after-fermentation in duced of dry hopping. If we consider that the brewer uses from a half to three-quarters of a pound of dry hops per barrel, the total quantity of sugars so introduced will amount, in round numbers, to 3.5 per cent. of this quantity, that is, from eight to twelve grams of sugar per barrel. This small amount of sugar is quite incapable of producing the observed effects, and that the freshening effect is not in any way due to this cause is clearly shown also by the fact that when the dry hops are submitted fora very short time to the action of steam, and they are afterwards introduced into the beer along with the small amount of water of condensation adhering to them, they are found to have entirely lost the power of inducing an after fermentation.

The second possible explanation that the vigorous after-fermentation is induced by the hops, owing to certain organised ferments introduced by them, has received our most careful attention, and we have made a very large number of experiments in this direction, both on a small and large scale,which, to our minds, are very conclusive. We can quite confirm the observations of various previous observers, that there certainly are several small varieties of yeast naturally adherent to the hop, and that these yeasts are capable of ready cultivation in sterilised worts and beer. There can be no doubt, also, that these “wild" yeasts occasionally develop and give trouble in the beer, but close observation, both in the laboratory and on a practical scale, has shown most conclusively that the particular conditioning property of the hop to which we are now drawing attention, is long antecedent to the growth and development of these wild yeast forms, and is quite independent of them.

We have now to consider the only remaining explanation of the freshening power of the dry hops in beer, viz., that they contain a diastase capable of hydrolysing the non-crystallisable products of starch transformation, which a beer always contains.

Our first experiments were performed with aqueous infusions of hops, made by macerating a large quantity of hops with a comparatively small quantity of water for forty-eight hours, and testing the filtered extract for diastatic power by digesting known quantities with a fixed volume of a solution of soluble starch at about 35° C., a temperature favourable to hydrolysis of a diastatic enzyme is present. Under no possible conditions could we in this way obtain an extract showing any diastatic power. We varied the experiment by taking the first filtrate from the hops and making another infusion with it, again repeating this until we had obtained no trace of diastase in solution, as not the slightest hydrolysis could be brought about by the extract in solutions of soluble starch, amyloins, or beer extract.

It might, perhaps, have been a reasonable deduction to make from these experiments that hops contain no diastase, but our previous experience on the extraction of hydrolytic enzcymes from animal and vegetable tissue had shown with what tenacity these ferments are sometimes held by the cell protoplasm, and that the tissue itself will often hydrolyse by contact when its aqueous infusions have but little or no such action. As it happened, also, there was in this special case another unsuspected disturbing cause, to which we shall make reference later on.

To determine if hops can hydrolyse by contact, 5 grams of unbroken hops were added to 250 c.c. of a solution of soluble starch, containing 2.5 grams per 100 c.c., and the mixture was digested at 30° C., with the addition of a little chloroform as an antiseptic. An exactly similar control experiment for correction purposes was carried on alongside, but in this case the whole had been previously boiled to inhibit any action. At the end of three days an increased reducing power was found in the unboiled sample, after due correction, equal to 0.883 gram of CuO per 100 c.c. This is equal to 0.656 gram of maltose; so that the 5 grams of hops in three 4 days had produced 0.625 X 2.5 = 1.640 grams of sugar calculated as maltose, or a little over one-third of the weight of hops employed.

In order to show that a fermentable sugar is really produced under these circumstances, another somewhat similar experiment was made, and the hydrolysed starch solution was fermented with yeast. On the disappearance of the free maltose, the solution, which still had a considerable reducing power, was distilled, and an amount of alcohol equal to 0.24 gram per 100 c.c. was obtained. This amount of alcohol corresponds to the quantity which would be yielded by the disappearance of 0.475 gram of maltose.

It is quite possible, under well-defined conditions, to determine with considerable accuracy the relative diastatic power of different vegetable tissues. As we shall shortly lay before the Chemical Society a somewhat lengthy paper dealing, amongst other matters, with the diastase of foliage leaves, in which the method is described at length, we will not enter into any detail here, but will merely give the results of some determinations of diastatic power of several kinds of hops acting under the standard conditions. The numbers really represent the actual number of grams of maltose capable of being produced from soluble starch and amyloins respectively by 10 grams of hops, acting for forty-eight hours at 30° C. :—

	Series A. Soluble starch solution.	Series B. Aymloins Solution.
	Grams of Maltose.	Grams of Maltose.
(1) 1891. Mid Kents	7.241	9.101
(2) 1892. Mid Kents	7.955	9.309
(3) 1892. Worcester	6	8.654
(4) 1892. Bavarians	3.752	5.665

Let us consider for a moment the full significance of these numbers. Taking No. 1 as an example, we find that 10 grams of these hops are capable, under the conditions of the experiment, of producing, in 48 hours, from an excess of soluble starch, 7.241 grams of maltose; whilst from amyloins, under the same conditions, the same amount of hops has produced by hydrolysis 9.101 grams maltose. In other words, within 48 hours the hops have, in the first case, produced by hydrolysis 72 per cent. of their own weight of fermentable sugar, and, in the second case, 91 per cent.

The conditions for hydrolysis are, of course, more favour able in the experiments we have just described than they are in actual practice, owing to the very fine state of division to which the hops had been reduced ; we, therefore, repeated the experiment in a different form, using this time a beer, instead of solution of soluble starch or amyloins.

The beer had an original gravity of 1,086, and, in order to prevent any fermentation occurring during the experiment, we added to it a few drops of chloroform. One gram of unbroken hops was added to 360 c.c. of this beer ; this is at the rate of one pound of hops to the barrel. The flask was then placed at a temperature of about 28° to 30° C. The beer had originally a cupric reducing power equal to 2.995 grams of maltose per 100 c.c. At the end of seven days this had increased under the action of the hops to 3.1903 grams, an increase equal to 0.1908 gram maltose per 100 c.c., or 0.687 gram for the 360 c.c. So we see that the hops in this case, acting upon a beer under conditions which may readily occur in practice, have, within seven days, produced from the non-crystallisable starch-products of the beer an amount of maltose equal to 68.7 per cent. of their total weight.

In a barrel of beer in which three-quarters of a pound of hopping-down hops have been used, this represents a production of 8.25 oz. of fermentable sugars in seven days, a quantity more than sufficient to account for the steady after-fermentation induced by dry-hopping."
The Brewers' Guardian 1893, pages 107 - 108.

Between 0.5 and 0.75 lbs per barrel of dry hops was pretty normal in the 19th century when beers were stronger. I've seen as much as a full pound in pre-WW I London-brewed Burton Ales. So the experiment is a good representation of what might happen in the real world.

It looks proven, then, that hops contain a diastase that can convert starch into sugar. My question is this: what is the effect of the very heavy dry-hopping that takes place nowadays? Does it provoke a secondary fermentation? Has anyone noticed this?

Why dry hop

I'm very grateful to Boak and Bailey for pointing me in the direction the Google Books version of the 1893 Brewers' Guardian. It's packed with interesting stuff.

Like this article on what the point of dry-hopping was. I can't say that I'd ever given it much thought. Iassumed that it was all about adding aroma to the beer. It seems that it's rather more complicated than that.

It seems that one of the points from a brewer's point of view was to bring a cask more quickly into condition. A bit like priming with sugar. In which case you wonder why only certain types of beer were dry-hopped. Though that did vary from brewery to brewery.

Boddington, for example, dry-hopped everything except Stout. Barclay Perkins dry-hopped their Pale Ales, Burton Ales and some Stouts, but never Porter or Mild Ale.

"ON CERTAIN FUNCTIONS OF HOPS USED IN THE DRY-HOPPING OF BEERS.*
BY HORACE T. BROWN, F.R.S., AND G. HARRIS MORRIS, Ph.D., F.I.C.

THE addition of a certain amount of dry hops to the finished beer in cask or vat is a practice which, for certain classes of beer, has been followed for so many generations that all traces of the origin of custom have been lost. Although, no doubt, the introduction of dry-hopping was due to pure empiricism, to that constant trying of experiments in all directions, and the selection of those methods which gave improved results, yet we find, as might be expected, that there are certain fundamental scientific principles underlying the practice which up to the present time have been but very imperfectly recognised.

Let us first of all inquire what are the objects which the brewer has in view in adding this small quantity of hops to his finished beer. In the first place he obtains a distinct aroma and flavour which his beer would otherwise lack; secondly, the addition of hops has a most decided antiseptic action, not only upon the beer, but also upon the cask after it is emptied; thirdly, the beer undoubtedly clarifies more rapidly than when hops are not added; and, lastly, dry-hopping induces an earlier and more persistent cask fermentation in the beer; in other words, the hops have a distinct “conditioning or freshening" influence.

It is the true explanation of that wonderful “freshening or conditioning” power of the hop which we wish to bring before you, as no sufficient reason has ever yet been given of this very remarkable function, which is perhaps the most important of any of those to which we have just called attention.

In order to satisfy yourselves of this influence of the hop, take, with all the ordinary precautions, two forcing-tray samples of a beer from skimming vessel, unions, or racking square after the primary fermentation is over. To one of these add a small quantity of hops, equivalent in amount of those used ordinarily in hopping down, and place both samples on the tray. As a rule, you will find that the sample without hops shows little or no signs of fermentation for many days, whilst that containing the hops enters into a brisk after-fermentation in a very short time, and attenuates rapidly, whilst the specific gravity of the other sample is almost stationary. This experiment is a mere imitation on a laboratory scale of what takes place under similar conditions in cask. There seem to be only three possible explanations of this action, which are as follows :—

(1) The hops contain a fermentable sugar; (2) there are, adherent to the hops, and introduced with them, certain “wild yeasts” which are capable of carrying on an after-fermentation in the beer more readily than the ordinary forms of yeast left in the beer after the primary fermentation has ceased; and (3) the hops contain a diastase: which is capable of hydrolysing the amyloins and dextrin of the beer, in this way, indirectly, supplying the yeast with a readily fermentable sugar.

We must now examine these three possible explanations of the facts in detail. As regards (I), that the effects are due to a certain amount of fermentable sugars initially present in the following experiment shows:—

Twenty grams of hops, after previous treatment with ether, were completed extracted with alcohol of 80 per cent. The aqueous residue, after distillation of this extract, was made up to 100 c.c., and examined for sugars. In the 200 mm. tube, the polariscope reading was — 1.4 divisions, and the cupric reduction was equal to 1.610 gram CuO per 100 c.c. This amount of reduction was not increased on treatment with invertase or boiling with dilute hydrochloric acid, so that neither cane-sugar nor any other carbohydrate capable of being hydrolysed  by acid was present. The optical and reducing properties point to a mixture of dextrose and levulose in the following proportions, expressed as a percentage on the amount of dry hops taken :—

Dextrose    1.55 per cent.
Levulose    2.10   ,,
Total sugars    3.65   ,,

The complete fermentability of these sugars was proved by fermenting them with yeast, and their solution gave glucosazone with phenylhydrazin acetate.

(To be continued.)


* Abridged from the Trans. Inst. Brew, Vol. VI., No. 4. By permission."
The Brewers' Guardian 1893, pages 93 - 94.

To paraphrase, there were four functions of dry hops:

1. to add aroma
2. kill infection in both the beer and cask
3. help clarrification
4. promote secondary fermentation

Why exactly did dry hops help condition beer? Well it seems from theie analysis that there are sugars present in hops. I'd have never guessed that. But what of wild yeast and diastase? You'll have to wait until next time to find out about that.

Horace Brown, in case you're wondering, was a well-respected brewing scientist.

William Younger dry hopping 1921 - 1939

I'm still labouring away at the number face. Which is why I've no time for proper posts. Just ones cheaply spun from a few shoddy numbers.

I'm pulling together all sorts of data for the Scottish book. Lots of which has never been assembled before. At least not that I've ever come across.

Dry hopping is a good example. Has anyone ever seriously compared English and Scottish dry hopping routines? I think not. Probably because bugger all people are interested in this sort of technical shit. Apart from me and hopefully a few geeks.

On my evening walk, I realised this table needs reorganising. Bum. More work. I was planning on having the book done by the end of next week. End of the month is more realistic. Especially if I keep adding stuff.

I estimated 35,000 - 40,000 words. I'm currently at 62,000 with a fair few holes still to fill. Two of the chapters have bugger all in their Techniques section. Need to fix that tonight with a new shaft down to the number seam.

Let me know what you make of this:

William Younger dry hopping 1921 - 1939 (oz. per barrel)
Year	1	3 Pale	XXX	DBS Btlg	Pale XXPS	Ext	XXP Btlg	LAE
1921	3.89	3.83	2.42	7.65	3.8			7.04
1933	2.01	2.06	1.98	6.10	2.02	6.52	1.82	4.85
1939	2.25	2.08	2.05	3.05	2.92	2.09	2.02	4.16
Source:
William Younger brewing records held at the Scottish Brewing Archive, document numbers WY/6/1/2/63, WY/6/1/2/70 and WY/6/1/2/76.

1 and 3 are Scotch Ales, XX is Mild, DBS Btlg is Stout and the rest are Pale Ales.

Bottling in 1914 - dry hopping

I've been promising you this for a while. And here it is, the final post spun from Arthur Hadley's 1914 paper on bottling. The bit about dry hops. I hope you're not too disappointed by it.

Reading between the lines, it sounds as if bottle-conditioned beers were always dry hopped. Non-deposit beers, as we learned last time, didn't hang around the brewery for long. They were stored for such a short length of time, they had little chance to have any effect.

"Mr, W. Scott said that the author had not dealt with the question of the dry hopping in tank of non-deposit beers. In his (the speaker's) opinion full value was not obtained from dry hopping, as when the hops were placed in the conditioning tanks loose for a limited period they simply floated on the surface, and when caged up, with a view of subsequent use in the copper, they swelled to such an extent that very little benefit was derived by the beer."
Journal of the Institute of Brewing, Volume 20, Issue 6, November-December 1914, page 528.

This seems an ingenious way around the problem of dry-hopping effectively in a short space of time.

"With regard to dry hopping, the members might remember that seven years ago he read a paper before the section, in which he gave a diagram illustrating a very effective method of dry hopping these non-deposit beers in the tank, by suspending the hops in a bag in the tank and circulating the beer through them by means of a perforated pipe which was placed in the centre of the bag, and was suitably connected to the pump outside. That system he had employed for the past 12 years with perfect success."
Journal of the Institute of Brewing, Volume 20, Issue 6, November-December 1914, page 529.

Here's Arthur Hadley's position:

"As to his practice with regard to dry hopping, they started some years ago dry hopping in the tanks, at the rate of half a pound per barrel. He found there was very little coming from the hop. He began to reduce it, and ended by reducing it entirely, and wiping it out, and for the last two years not a dry hop had gone into the beer. They had saved hundreds of pounds thereby, and he did not think anyone could tell the difference. The amount entering the beer was so infinitesimal that it was not of the slightest use, and there was really not the slightest need for it."
Journal of the Institute of Brewing, Volume 20, Issue 6, November-December 1914, page 532.

A waste of time, basically. Half a pound per barrel is quite a lot. Whitbread's X Ale, had about 1.25 lbs of copper hops in 1914. FA, their low-gravity bottled Pale Ale, about 2 pounds*.

It's another confirmation, in a way, that flavour wasn't the top priority of bottled beer drinkers.






* Whitbread brewing record held at the London Metropolitan Archives, document number LMA/4453/D/01/079.

Bottling in 1901 - hops

As promised, we've now moved on to the effect of hops on bottled beer. Fascinating stuff, I'm sure you'll agree.

First it's the copper hops.

"C. The flavour of the copper hops.

The blending of hops for use in the copper has always been an important question to the brewer since the use of hops became general, and in some cases a particular brand of ale has obtained notoriety very largely on account of the particular blend of hops used. The softer the water used the more important this question becomes. Although perhaps the most important function of the hop is its preservative action, the bitter flavour which it gives ale is almost as important, and this is dependent more on quantity than quality, as shown in the extract obtained from the copper hops."
Journal of the Federated Institutes of Brewing, Volume 7, Issue 2, March-April 1901, page 199.

The author seems to be using notoriety in a slightly different sense from its modern meaning. I read it as a synonym for "famous" without the perjorative element of modern usage. That aside, the copper hops are shown to be purely for bittering and not aroma purposes.

"D. The flavour of the hopping-down hops.

This is perhaps the most distinct and characteristic flavour of all. The aroma of the hop, which differs so much with different growths and different samples of hops, is very delicate and only to a very slight extent withstands the boiling process, consequently it is to the dry hops, added to the newly racked ale, we look for the most pronounced hop flavour as apart from hop bitter.

No doubt fine Kent hops give the most delicate hop flavour, but Worcesters and Farnhams are not far behind, and, being larger, more robust hops, are much in favour for hopping down.

As English hops generally lose much of their fine aroma when stored in the usual way, it is not at all unusual to use a mixture of English and foreign, more especially as the summer advances, and one-half Kents with one-half Burgundies or Bavarians produces very nice-flavoured ales.

Cold storage enables the brewer to have new hops all the year round, as, stored at a low temperature, hops practically remain unaltered, and, if desirable, a brewer can hop down all the year round with Kents or Worcesters and maintain a constant fine flavour. Certainly cold storage should improve the flavour of summer- and autumn-brewed ales in this country."
Journal of the Federated Institutes of Brewing, Volume 7, Issue 2, March-April 1901, pages 199 - 200.

Interesting that they were totally dependent of dry hops for hop flavour and aroma.Which makes it sound like there were no late additions at all. 19th-century hop additions are a tricky subject to get a handle on. They generally aren't recorded in brewing records, leaving us dependent on technical brewing literature. Which is problematic as, in my experience what's described in the literature doesn't always match brewing practice 100%.

The author seems to be saying that English hops deteriorated more quickly than Continental ones, hence the recommendation to use some Burgundy or Bavarian hops late in the season, when hops were closing in an being a year old.

Unless, of course, you invested in a cold store. Stored cold English hops wouldn't lose their aroma and could easily be used up to 12 months old. Which this handy little table confirms:

Analyses of Fuggle's hops during storage
	cold store			warehouse
storage period	alpha resin	beta resin	preservative value	alpha resin	beta resin	preservative value
	6.28	8.6	91.5	6.67	9.26	97.6
5 months	6.22	8.2	89.5	5.83	9.17	88.8
9 months	5.72	8.25	84.7	4.72	9.34	78.5
14 months	5.84	8.54	86.9	3.48	8.64	63.6
19 months	5.15	8.92	81.2	3.21	9.9	55.1
Source:
"Brewing Science & Practice" H. Lloyd Hind, 1943, page 349

You can see how little the alpha and beta acid values declined in 14 months in a cold store. While in a warehouse almost 50% of the alpha acis was lost over the same period.

There's still lots more to come from this wonderful article. Bet you're pleased to hear that.

Mr. Bass talks about hops

Time for a change of pace. And decade. And parliamentary committees. Today it's the turn of the Select Committee on Hop Duties. Great book. A white-knuckle ride of thrills and drama. Not really, but there's still something specuial about Mr. Bass discussing hops.

7181. Chairman.] Have you any objection to tell the Committee what is your annual consumption of hops? —My concern has consumed since October last 11,000 cwt. of hops, and the price of the English hops that we have bought has been less than 5L. per cwt. We have also bought a considerable quantity of Bavarians in the spring of this year, and those have cost upon the average about 6L. 12 s. per cwt. We attempted to buy Bavarian hops in the autumn of last year, there having been a remarkable scarcity of good English hops; but the price that we were asked was 9 L. per cwt. nearly up to Christmas, and then I think it was reduced to 8L. Up to December last we were unable to buy a single Bavarian hop on account of the high prices. After the Bavarian brewers and buyers had supplied themselves there was still a surplus left, and we had an opportunity of going into the market upon more favourable terms; and we have bought a few thousand cwts. of hops, something under 3,000, at an average price of 6L. 10s. or 6 L. 12 s. per cwt.; and we are holding now a considerable quantity for yearlings, because, as has been before stated to the Committee, we find the Bavarian yearlings deteriorate to a much smaller extent than the East or Mid Kent hops.

7182. What sort of English hops do you buy?—We buy principally the best quality from Mid and East Kent. I believe that since I have been concerned in the trade, which is now nearly 40 years, we have never used a pocket of Sussex hops. We use a few of the finest Worcester hops in the beginning of the season. Mr. Smith, who gave evidence before this Committee, has attained the production of fine Worcestershire hops, and we buy his hops almost every year, and a few other selected samples of Worcester hops.

7183. Do you consider his hops a particularly good specimen?—I think it a superior specimen of Worcestershire hops.

7184. Would you consider his hops an average specimen of Worcestershire hops ?—By no means ; I should say they were at least 25 per cent. better than Worcestershire hops in general.

7185. Mr. Brand.] Will you inform the Committee what proportion of hops are used in brewing different varieties of beer ?—My opinion agrees with what has been generally stated to the Committee, that for common beer the average quantity used would be as much as from eight to 10 lbs. of hops to a quarter of malt; but that for pale ale, and every superior quality of beer, very often as much as 18 lb. is used per quarter.

7186. Does beer for exportation generally contain a large portion of hops, or otherwise ?—Always a large portion; it is indispensable.

7187. What number of pounds per quarter should you say was used in them? —There is a class of beer that is exported which requires from 16 lbs. to 18 lbs. a quarter ; strong beers for export do not take so much.

7188. I see that in the year 1856 the value of beer exported amounted to a million and a half of money ; could you form any opinion as to the quantity of hops embraced in that exportation?—I take it that you may put it down at 700,000 barrels, and the quantity of hops used is not quite 5 lbs. a barrel, so that I think you will find that that will come to about 3,500,000 lbs. weight of hops. I beg to observe to the Committee that there is no drawback whatever 23 July 1857. allowed upon that; so that upon this 3,500,000 lbs. of hops exported in the shape of beer, the brewer has paid 2 d. a pound upon them for which he has not got a penny back in the shape of drawback. There is the drawback upon the malt, but on the hops there is none whatever.

7189. Sir Edward Dering.] There is no drawback upon hops when manufactured ?—No.

7190. Mr. Brand.] Has exportation largely increased of late years ?—Yes.

7191. Do you anticipate a further increase?—I have no doubt of it. We have received orders from Australia for double the quantities received last year.

7192. Does that observation apply to other concerns besides your own ?—To a certain extent. We have the good fortune at this moment to stand rather well in foreign markets, but I should think there is a general increase in the foreign demand.

7193. Are you exporting beer to foreign countries as well as to Our own colonies ?—Yes; there is a considerable export to Paris, and some also to the United States; some to the Dutch settlements in India, under very heavy duties, and some little up the Rhine to Germany.

7194. Mr. W. Martin.] Do our own East Indian settlements take a great deal ?—They take a certain quantity, but nothing in comparison to the Australian colonies.

7195. Mr. Brand.] Do you expert beer up the Rhine to compete with the Bavarian beer ?—I do not think it is for that purpose; it is sent rather to supply the English tourists who go up the Rhine.

7196. Chairman.] You have said that at Paris, in the Exposition, English hops were placed behind Belgian hops ; what class of English hops were they ? —I do not know.

7197. Have you ever seen Belgian hops in England ?—I have used them.

7198. Were they Popperingue hops?—Yes.

7199. Mr. Brand.] Do you think, from your experience, that the English hops are inferior to the Belgian hops ?—I think the ordinary run of English hops are inferior to the finest Belgian. I do not attach very great importance to the result of the Paris Exposition, because I do not believe that England was fairly represented there.

7200. Chairman.] Did any other countries exhibit?—Yes, America and Canada, and I think Poland; but I cannot speak exactly upon that. Allow me to explain with regard to Farnham hops. We find that Farnham hops are very rarely brought into the general trade of the country, but they are principally used in the country where they are grown, and where there is a preference for them. I believe that at Weyhill Fair, which is a famous fair that takes place in the month of October, the highest quality of those that are grown in the town of Farnham fetch a higher price than any other hops.
7201. Do you never use them?—Never. We tried the experiment, and the conclusion we came to was that the East Kent are very superior.

7202. Mr. Brand.] Is it your practice to mix the Bavarian hops with the British grown hops, or do you use the Bavarian hops alone ?—We generally mix them; not that we should object to use Bavarian hops alone, but it suits us to mix them with other hops. It is advantageous in this way, that we have paid this last year a much higher price for Bavarians than we have for any English hops, and it would be a little too costly to use exclusively Bavarian hops.

7203. Putting the element of price out of the question, should you prefer using Bavarian hops ?—Yes. "Report from the Select committee on hop duties", 1857, pages 364 - 365.
Evidence given by Michael Thomas Bass.

I'll pick out the bullet points for the lazy amongst you.

• Bass used East Kent, Mid Kent, Worcester and Bavarian hops
• Bass liked Bavarian hops the best
• Bass thought East Kent hops superior to Farnhams
• Bass didn't use Sussex hops
• ordinary beers hopped at 8 to 10 lbs a quarter of malt
• export Pale Ale hopped at 18 to 20 lbs a quarter
• Bass used a mixture of different types of hops in their beers
• Bavarian hops didn't deteriorate as quickly as Kent hops
• beer for export (I assume Pale Ale) was hopped at almost 5 lbs per barrel
• Bass exported large quantities of beer
• Bass exported more beer to Australia than to the British East Indies

One other point. I'd been assuming up to this point that Bavarian hops were Hallertauer. From a later passage in this report, it's clear that the hops were actually coming from the Spalt region. So I guess they were Spalt.

About the hopping rates mentioned . They tally pretty well with what I've seen in brewing records. Reid IPA from 1839 was hopped at 26.6 lbs to a quarter of malt, 5.88 lbs per barrel. The 8 to 10 lbs per quarter is spot on for Mild Ales. In 1850, Whitbread's X Ale had 8lbs of hops to a quarter of malt, 2.41 lbs per barrel.

Dry hops for KK Bott.

More random stuff from the logs. Bet you can guess how I've been spending most to my time.


This note, stuck inside a Barclay Perkins brewing log, gives details of the dry-hopping scheme for the bottled version of KK.

"4 oz Saaz after 4 or 5 days rolling" What a great description. I remember being told that they used to regularly roll casks of Russian Stout around the brewery yard. I wonder if anyone still does that?

Barclay Perkins seemed to like using Saaz for dry-hopping their Strong Ales. I wonder why?

Dry hopping at Younger in 1885

Dry hopping. It's a tricky subject, when it comes to brewing records. Some brewers didn't bother to record it at all. Others did. One of those is William Younger.

Not only do the logs include details of the dry hops per brew, they also included a cut-out-and-keep guide to their dry-hopping regime. You can see it to the left.

The first bit gives the hops used:

1/2 Wurtg. '84
1/4 Amer. '84
1/4 Kent '84

Now I hate to keep banging on about this. But I'm, going to anyway. Look at the origin of the hops. The first looks like Württemberg. The second is America. As with most British breweries, by the second half of the 19th century a significant proportion of the hops were foreign. So would this persuade Younger to use fewer hops because of the expense? Bollocks. They were actually at an advantage, over many other breweries because Edinburgh is a port (well, Leith is, to be precise). It would be cheaper to get American hops to Edinburgh than to, say, Burton, because they could be delivered directly by sea.

The rest of the image shows number of ounces of hops per barrel added. In the case of the stronger beers, it was rather a lot. No.1 Ale, with a gravity of 1103 a nice session beer, led the way with a whole pound. P and XP, in case you're wondering, are Pale Ales.

This isn't the full list of Younger's beers of the period. Most of the shilling Ales are missing. For one simple reason. They weren't dry-hopped.

I really should try to get out more. All these log details. You'll be thinking I spend all my time looking through these things.

Scotland vs England - the kick off

I've just had my first quick glance. Of how Scottish beers stack up against the English. Fascinating.

I've got a table of 500 beers brewed between 1880 and 1914. Three Scottish breweries: William Younger, Maclay, Thomas Usher. Three English breweries: Barclay Perkins, Whitbread and Truman (Burton). I did the stupidest possible sort: pounds of hops per barrel. Bet you're wondering what the result was, aren't you? Be patient.

One thing I didn't need a sort to see. Who had the longest boil times. There was a very clear winner: Truman. There's no great difference in pitching temperatures. All are 57º - 61º F. In general, the stronger the beer, the lower the pitching heat.

William Younger brewed beers with the largest range of gravities: 1030 to 1110. The English breweries didn't brew hardly anything below 1050. Younger brewed several very sweet Stouts that were unlike anything brewed in England. And were still brewing Table Beer a couple of decades after London brewers had dropped it.

Younger brewed a bit of everything. Shilling Ales, X Ales, Pale Ales, Sweet Stout, Stout, Dinner Ale. And loads of other things I can only guess at. SLE, SE, MM, LDE. They also had a range of numbered Ales:, 1, 2 and 3. Very like Burton Ales brewed by Bass or Truman.

I bet you're still wondering about the winners and losers in the hopping race.

The ten most heavily hopped beers were all brewed by either Barclay Perkins or William Younger. Surprisingly beating Truman (at least for me).

The least heavily-hopped beers were all Scottish. No surprise, as some Scottish beers much weaker than any of the English ones. And those Younger Stouts with second-hand hops.

Younger's No. 1 Ale contained more hops than Truman's No. 1 Ale. They were similar beers, of a similar gravity.

One thing is clear. The blanket statement "Scottish beers were less hoppy than English beers" is not true. At least not 1880 to 1914. But I'm sure it's a lot more complicated. Things always are.