J. Inst. Brew.. May-June, 1983, Vol. 89, pp. 189-194 189HORACE BROWN MEMORIAL LECTURE

EXPANDING BREWING TECHNOLOGYBy J. R. Hudson

(Brewing Research Foundation, Lyttel Hall. Nutfield, Redhill. Surrey RH1 4H Y)Received 7 December 1982In the past twenty years there have been numerous technological innovations which have improved the efficiency and reliability of both malting and brewing. Several of these have stemmeddirectly from research discoveries. In other cases, research has been needed to ascertainwhether innovation at one stage in the process brings a need for adjustments at other stages.

Because of the changing climate and pressures on the Industry, e.g. in market requirements,availability of raw materials, considerations of food-safety and cost of energy, brewingtechnology must continue to evolve and will contribute to and gain from developments in new

biotechnology.Key words: beer quality, brewing, flavour, hops, malting,research and development, survey.

IntroductionAt the start of Horace Brown's career, brewing was still anart. He and his contemporaries initiated the scientific inves

tigations that were to convert brewing from an art into atechnology. When Horace Brown's career drew to a closesome SO years later, the industry had taken giant stepstowards technology and research and development had been

established as vital activities to allow brewing to adapt to thesocial and economic changes surrounding it. For example,in the 188O's a little or a Tew very famous beers travelledgreat distances, even as far as India, but the vast majority

travelled no further than a horse and cart could move it ina day. By the 1920's transportation had been revolutionised.

Ale-brewers, hitherto, had lived with a trade pattern whereinthe vast majority of beer was consumed within about twoweeks of production. They now had to adopt techniques

which would ensure that the quality of beer would resistdamage during storage and transport.

Horace Brown's achievements were tremendous. He hadan advantage in that reputable scientists of his day wereallowed, and indeed expected, to be authoritative on allbranches. Thus he had complete confidence to investigatebotanical, biochemical, chemical and microbiological

matters and he made permanent scientific contributions oneach of them.

A great deal of research effort is doomed to frustration.Horace Brown's successes were far above the average.10Nevertheless, he was far too wise to expect that the scienceof brewing would be completely elucidated in his lifetimeor indeed that it ever would be complete, because ofthe ever-changing pressures on the industry. Thus, he was

somewhat saddened that Boards of Directors expected finiteinvestigations which would establish a single and permanentbrewing technology. Eventually wisdom prevailed and

recognition that scientific investigations, and especiallythose of Horace Brown, had brought technical benefit which

in turn safeguarded the industry's economy, brought theBrewing Industry Research Foundation into being.

When he delivered the ninth lecture in tribute to HoraceBrown, Sir Ian Heilbron reviewed the findings of the firstseven years ofresearch at Nutfield.17 Those years representeda large investment and displayed a very great degree of trust

by the commercial companies in a group of scientists newto the industry. At the outset the group did not understand

the terminology and special mathematics of brewing andhad the gravest difficulty in understanding the problems asdescribed by the brewersa difficulty that Horace Brownwould never envisage. By I9S8 this had changed and sufficient expertise had been built up at the Foundation to

underpin the remarkable improvements in the technology ofmalting and brewing which would be introduced in the following 20 years.

Timeliness of researchThe history of research on the hop bitter substances illustrates that whether or not industry responds to research find

ings, depends on combinations of circumstances andpressures.

It is now commonly accepted that the vast majority of thebitterness in beer derives from the a-acids of hops, in themain, by direct isomerisation but to some extent by way ofoxidation products.20 It is usual to calculate the utilisation

of potential bitter substances from the equation:21

% Utilisation =-Bitterness units in becrx 100Concentration of a-acids added to wort

Using this measure, the range of utilisation reported fromBritish breweries in 1958 was 15-29% and the concept ofextracting the bitter principles, isomerising them and thenadding them after fermentation so as to bring utilisation intothe range 75-85%, was being developed. However, neither

the elegant chemistry of Howard & Tatchell" nor thepilot-scale demonstrations of Hall14 could arouse much

interest from production brewers at that time. There weretwo potential process-defects. Firstly, the hop-back requiringa substantial depth of spent hop as filter medium, was still

the main means of separating off hot-break. Secondly, whenfermenting unhopped wort, many strains of Saccharomycescerevisiae did not form a sufficient head to be dealt with bythe available skimming systems. Hence Whitear's studies45of the storage conditions applied to hops, which started inthe early 1960's, had a much more direct commercial

impact. The outlook for hop extracts only became at allrealistic when the Whirlpool separator had been introducedand when the use of cylindro-conical vessels also became

commonplace.Almost 10 years of commercial trial and adaptation ofpowders, pellets and extracts led to a kind of equilibrium by

1975. From the research point of view this outcome was notas exciting as had been expected in 1960. Still the majorityof hops were used as whole hops (Table I) and the lesserportion was divided between pellets and extracts, with onlya very small usage of isomcrised extracts. This latter fact was

very likely due to inability to obtain suitable quality at a realistic price. Nevertheless, considerable advances had beenmade alongside the superior hop-varieties which had beenintroduced. Within breweries the bitterness of beer could be

TABLE I. World Hop Usage in 1975

Hop form

Hop conesHop extractsHop pellets

x 10O0 Zcntncrs

1237525435

% of world crop

5624

20

190 HUDSON: BREWING TECHNOLOGYcontrolled and hop-utilisations as high as 40% were reported

using conventional wort-boiling. Doubtless the main contributor Jo this improvement was the adoption of techniquesto suppress the formation of yeastheads in cylindro-conicalvessels." The acreage of hops needed to bitter 39-8 millionbarrels of beer was 14,420 in 1978 compared with 21,130acres for 23-8 million barrels 20 years earlier. Considerableeffort had been expended on research and development and

further effort seemed scarcely justified.The outlook changed yet again in 1976 when Laws andco-workers25 discovered that the valuable constituents of

hops can be extracted with liquid carbon dioxide. The ratherselective action of liquid carbon dioxide yields a productcontaining virtually all of the a-acids and essential oils of

hops and with only p-acids as significant quantities of unwanted material (Table II). Hard resins, pigments and poly-phenols are not extracted. Thus, these extracts have the

merits of stability and relatively small bulk which are advantageous in transport and storage. In contrast to hop extracts

made with organic solvents, they retain the aroma characteristics of the parent hops so that they have flavour potentialbeyond bitterness. Extracts made with liquid carbon dioxideperformed so well in commercial trials that the first commercial plant for their preparation was in operation by 1980"

to be joined by two more in 1981.5I2 The order of throughput for each of these plants is 25,000 zentners per annumand represents the first large-scale use of liquid carbon

dioxide in the food and beverage industries. The 4 yearselapsed time between laboratory discovery and commercial

production is remarkably short for a process ofthis kind andillustrates that the brewing industry is anxious to take advantage of new technology, providing that it meets proper standards of quality and economy.

TABLE II. Constiluents extractedbyCO2

Constituents

a-AcidsB-Acids

Hard resinsTotal resins

Hop oilFats and waxesWater

% w/w

40-6030-45

Trace70-98

2-100-10

1-5

An especially important advantage which extracts prepared using liquid carbon dioxide have over those made withorganic solvents, is that the essential oil which is responsiblefor desirable aroma and characteristic taste, is obtained invirtually the same state as exists in the parent hops. Hence,this type of extract has already made an impact as a substi

tute for dry hops with consequent benefits in consistent andcontrollable flavour and in avoiding mechanical and hygienedifficulties.'12 There is prospect of similar improvement with

regard to control of kettle hop flavour. Nevertheless, themain target of all hop research, utilisation of the bitter-potential at better than 90%, still lies ahead. Because a maincost hitherto, in manufacturing isomerised hop extracts hasbeen incurred by the need to eliminate polyphenols, hard

resins and the like, before treatment with alkali, the liquidcarbon dioxide process, which leaves such material in the

spent hops, at least brings the target within range.

Malting technologyThe second Horace Brown lecturer, E. S. Beaven3 lived inless strenuous times than the 1980's (as evidenced by the factthat he delivered his lecture in 1930, but it did not reach the

Institute's Journal until 1934). His contribution was to breedbarleys suitable for malting and the successful varieties of his

[J. Inst. Brew.day were Spratt Archer, Plumage Archer and Hunter. These

were still the prime malting barleys of the 1950's until theadvent of Proctor in 1955.6 When it first appeared, Proctorwas not hailed as the variety to meet the highest expectationsof maltsters and brewers. It did not perform at all well underthe conditions of malting that had served so well with Spratt

Archer. In consequence many breweries struggled with setmashes because of the mechanical over-modification anddoubtless, there were many, many barrels of beer spoiledbecause of the excess of amino nitrogen which survived

fermentation. However, the market was changing rapidly. Asthe barley crop expanded, maltsters had lost their authorityto dictate what varieties would be grown and by 1958,

Proctor was 55% of the total crop. There was no alternativebut to adapt the malting technology and for a decade or

more, Proctor was the staple barley for malting. However,by the early 1970's, so many other varieties were introduced

with superior yields and better resistance to disease, thatProctor declined to less than 5% and has now disappearedfrom the National Institute of Agricultural Botany's list ofrecommended varieties. Since then Mans Otter waxed andis waning, and new varieties which must be regardedseriously by maltsters, appear almost annually and frequently they call for adjustments in malting techniques. The

latest of the star varieties, Triumph, has even re-introducedthe spectre ofdormancy which had seemed ofrelatively little

importance for so many years.This experience, combined with the 'high nitrogen* seasonof 1975 which caused needless anxiety and the extreme of

1976 when there was so little barley of any kind, emphasisethat it is the function of the Research Foundation to devisesufficiently flexible technology to produce sound malt fromvirtually any barley. Obviously it is ofadvantage to have var

ieties that malt readily because the process will then bemanaged the more economically. However, providing thatmalt of sound quality is produced, barley variety is of no significance in the brewing process or in terms of beer quality.

When Spratt Archer was the main variety (Table III) germination times of 10 days were normal so that includingsteeping and kilning, process times of 14 days were ordinary.

In addition malting losses of 10% were commonplace. Nowadays, the corresponding times are 4-5 days, and maltinglosses are 5% or less. To some extent these improvementsare attributable to improved engineering giving better control over temperature and humidity, along with more ef

ficient turning and transfer of the grain. However, the mainadvances are derived from basic research on the physiology

of the grain.

TABLE HI.

Year

19501980

Malting Time/Malting Loss

Malting time(days)

144-5

Malting loss(%)

105

The first serious impact of the Foundation's research onmalting technology resulted from Pollock, Kirsop &EsseryV2-33 34JS studies on dormancy. Water-sensitivity wasrecognised as one form of dormancy and it focused attention

on the need to provide the embryo with a ready supply ofoxygen during germination. From this there developed theprogrammes of aerated and interrupted steeping31 which are

now regarded as almost traditional parts of technology, andwhich have had permanent economic benefit.

For several years the alterations in steeping coupled withthe superior temperature control and mechanical handling

which were also introduced, seemed to be sufficient changeand improvement for the industry to deal with and the

Vol. 89, 1983] HUDSON: BREWING TECHNOLOGY 191

general advice was to turn research effort to other matters.However, research on malting continued and the next development represents a reversal of the usual order of discoveryand exploitation. The plant hormone, gibberellic acid wasdiscovered in Japan, evaluated but not used in Sweden, but

produced commercially by ICI and used by the maltingindustry in Britain and several other countries.

The greater mass of the barley grain is the starch whichis the main source of brewers extract. The importantcomponents ofthe grain in making the starch extractable arcthe aleurone layer and the embryo. It is the aleurone cells

which generate the enzymes, i.e. a-amylasc, the glucanasesand the proteases, which in turn, hydrolyse the contents ofthe endosperm. However, the aleurone does not start to

generate these enzymes until it receives a message to do sofrom the embryo and this message arrives in the form of thehormones the gibbcrcllins, of which gibbercllic acid is typical. The next main impact ofbiochemical research on malt

ing technology, was the introduction of treatment withextraneous gibberellic acid at rates of 01-0-2 ppm, to regu

larise and accelerate the germination process.40 Meanwhile,the world of new biotechnology outside malting and brew

ing, is still puzzling as to how gibberellic acid might beemployed, for example, to improve the cultivation of grapesor to provide extra biomass to be used as a source of energy.

Because the commercial application of gibbcrcllic acidhad been achieved without waiting for complete elucidationof its function and effects, further laboratory investigations

were undertaken in the late 1960s. These brought Palmer torealise that left to itself, in the time available for malting, thebarley embryo passes gibberellin to only a small proportionof all alcuronc cells. Palmer then invented the process ofabrasion whereby the husk and underlying layers are just suf

ficiently damaged for extraneous gibberellic acid, applied insprays or in steep-water to pass directly to the aleurone

layer.*0 In this way the enzymes which modify the grain,both chemically and mechanically, can be distributed

throughout the corn much more homogeneously. TheAbrasion Process is notable in that, assisted by the fact

that it could be achieved by modification of an existingmachine, it passed Prom laboratory discovery to commercialapplication in as little as 3 years.13

The Abrasion Process illustrates that malting and brewinginvolve series of compromises and that to obtain full benefitof innovation at one point it may be necessary to make

adjustments along the process. Also, it emphasises the pointthat it is sometimes necessary to reserve judgement on thesuccess ofa new process for as much as ten years. Thus, abrasion was first taken up by sales malting companies, probablybecause it can be used to facilitate the malting of some

batches of barley which would otherwise be unattractive.However, it has probably stood the test of time best, in thehands of brewer maltsters. The explanation appears to bethat if the new malting process disturbs the brewing performance, the combined companies can explore reasons and

make adjustments to fit the needs of particular brewing programmes. For example, Brookes7 has shown that the most

efficient abrasion, advocated from the original research,resulted in significantly greater modification than wasacceptable and led to unsatisfactory elution ofextract in the

mash-tun. The remedy was to apply a lesser degree of abrasion. It would be unrealistic to expect sales-maltsters to varythe degree of abrasion to meet the separate demands of thedifferent brewing systems used by their customers.

FermentationBrewers have only limited control over yeast and fermentation. The means of control lie in altering the compositionof won through choice of grist materials and mashing conditions at brewing, and by pitching rate and temperatureadjustments in the fermentation room. Brewers are said to

control the growth of yeast but in fact suffer the amount thatcoincides with their required degree of attenuation. Theexpectation in earlier years was that vastly improved control

would be gained by turning to continuous fermentation andRudin & Hough39-40 published accounts of very promisinglaboratory trials.

The expectations of control over quality, of acceleratedfermentation and of savings in cleaning operations, wereall so great that investigation and development was soon

taken up in very many commercial companies. Meanwhile,imaginative and inventive schemes were put forward by

Portno36-37-38 and others.18 However, the outlook on batchfermenters suddenly altered and continuous fermentationnever achieved extensive commercial success. The reasonwas that the engineering designers for reasons of economy

in construction, turned the attention of the brewing worldonto cylindro-conical fermentation vessels.

Shortly after the turn of the century a Swiss namedNathan27 had designed new fermentation vessels, as illustrated in this Journal. 1930, 36, 545. He combined it witha maturation system whereby undesirable flavour consti

tuents were purged from green beer with carbon dioxide.Nathan campaigned to have his vessels adopted at least until

1930. In that year he addressed sections of the Institute inEdinburgh28 and in London29 and entered into public debateon the merits of his system with such masters ofbrewing sci

ence as Chaston Chapman, Lloyd Hind and Julian Bakerbut to little or no avail. It was not until tower vessels werebeing advocated as continuous fermenters that the merits of

Nathan's designs were finally acknowledged. At the sametime centrifuges of sufficient performance to separate yeast

without damaging beer quality, became available, so thathead-formation and sedimentation became much lesser constraints in selecting yeast. Hence, whereas dwell times in traditional fermenting vessels had been one week with most of

that time devoted to natural separation of yeast rather thanto actual fermentation, 2-5 day cycles became feasible. Inaddition, the new vessels were readily suited to the collec

tion of carbon dioxide and to 'In Place Cleaning' methods.Most of the advantages claimed for continuous fermentation

had disappeared, largely because studies of continuousfermentation had provoked the reactions which made batchfermentations so very much more efficient.

The change to cylindro-conical vessels caused a reappraisal of yeast-performance. Although yeast separation wouldbe achieved by sedimentation into the cone, probably sup

plemented by centrifugation for the main bulk of beer, ale-brewers wanted to retain the strains of S. cerevisiae

responsible for characteristic flavour in their products. Thehead-forming capacity which had been so vital before wasnow an embarrassment and had to be suppressed in orderto avoid waste of capacity. More importantly, closer attention to the supply of the necessary level of oxygen was

needed to ensure efficient fermentation.1 Formerly, the difference between top and bottom fermentation systems wasa main feature distinguishing lagers from ales. Now it seems

only the difference in temperature is significant at the fermentation stage.

During the trials of continuous fermentation there wasconsiderable difficulty in matching the flavour of existing

brands of beer. This raises two points. Firstly, when newmethods are being developed for the production of existingbrands it is quite often the case that the demands for flavour-

matching are more stringent than can be attained betweenbatches from the existing process. This situation should alternow that routine Flavour Profile evaluations reveal the truevariation between batches but it has afflicted research anddevelopment teams and caused some worthy projects to beabandoned. Secondly, it should be noted that in the main,

investigations of continuous processing were concernedwith the physical and engineering aspects of the process.Traditional materials were used to produce the worts of the

192 HUDSON: BRKW1NO TECHNOLOGY [J. Inst. Brew.

same composition as had been fermented in batches. Toreach the existing specifications ofbeer-quality it was usuallyjudged necessary to achieve the same rates of yeast multipli

cation as obtained in the batch systems. With hindsight, itis probable that a more flexible approach to materials andwort composition would have yielded much more advantageous results.

Impending researchThe lifetime of BRF has coincided with a period of greattechnical change and improvement in the brewing and malt

ing industries and there is a temptation to be content withconsolidation and retrenchment. However, the pressures onthe industries change in unforeseen ways. Most of todaysprocess and plant were devised at a time when energy wasstill cheap and when concern about food-safety, though real,

had not reached the near hysteria that prevails nowadays.The world at large is casting around for the means ofproduc

ing enzymes and seeking new uses for them under the guiseof biotechnology. Maltsters have always developed vastly

more enzymic capacity than is needed in brewing and thendestroyed a large proportion with valuable heat-energy. Thegreater proportion of heat applied on the malt kiln, is usedto evaporate water so that the malt can be transported andstored. The first stages in brewing are to crush the grain andslurry it with water. No doubt research will eventually findways of avoiding these contrary requirements.

Brewhouse.A main move to counter the increase in costof energy has been the adoption of high-gravity brewing and

fermentation. This avoids the heating and movements ofconsiderable bulks ofwater. However, the scope fordevelop-

ment is limited because existing brewhouses become intolerably inefficient when producing worts of gravity exceeding

1060 and because fermentations at gravities higher than1060 carry a barley wine type offlavour. Approaches to control the flavour have achieved a measure of success by judicious supply ofoxygen during fermentation24 but, apart froma proposal to use high pressure mash filters, there has been

very little consideration of how to modify the mashing process.

To operate at gravities above 1080 or even 1100 willrequire solid/liquid separators quite unlike lautcr tuns. Inthat case it will be timely to reappraise tube-converters

possibly heating the mash by infra-red radiation. Currentstudies of flavour stability should by then indicate

whether or not, action can be taken at the mashing stage toneutralise the precursors of the carbonyl compounds whichare responsible for the stale flavour which develops in pack

aged beer.Assuming that the liquid carbon dioxide extract of hopsis completely successful in the next decade then brewers willbe spared anxieties from the empirical calculation of hop-

utilisation quoted early in this lecture. The measurement ofa-acids is usually by conductometry or sometimes by spec-trophotomctry and neither technique is specific. Provided

measurements are made soon after harvest the discrepanciesare not very great. However, the optical densities of iso-

octane extracts of beers bittered at the copper stage, isonly an empirical estimate of bitter-substances. With the

transition to post-fermentation bittering, brewers will haveexact measure of the contents of iso-a-acids and the burdenof responsibility for utilisation will be transferred to the

extract manufacturer.

FermentationAt present compromises have to be madein the selection ofyeast strains. Main features in the selectionofa brewing yeast are the characteristic flavours which indi

vidual strains confer and the ease with which the cells separate from beer when fermentation is complete. In order

to secure a particular flavour therefore, it may be necessary

to sacrifice some efficiency in fermentation. The new techniques ofgenetic engineerng should provide real control overfermentation performance. Already it has proved possible tointroduce superannuating properties into strains which do

not have the ability to produce vinyl guaiacol from fcrulicacid.43 This latter ability is the one which causes thedamaging phenolic flavours when worts are fermented withS. diastaticus.

It is likely that there will soon be commercial applicationofstrains which can produce low-carbohydrate beers by producing their own amyloglucosidascs to supplant the fungalenzymes which are employed at present. The more distant

target is to persuade yeast to excrete enzymes, capable ofmodifying the composition of beer so as to improve its quality. For example, a yeast which secretes protease could im

prove the colloidal stability of beer during fermentationinstead ofthe conventional treatments with papain after fermentation which are now so widespread. Likewise, the production of an appropriate glucanase could improve the

filterability ofbeer, convert p-glucan, which at best is a neutral constituent and at worst an extra hazard to quality, into

useful fermentable extract.

Beer-quality.Haze-life: Three decades of research on the compositionof hazes, on the functions of constituents and development

of preventive measures, have given brewers a sufficient technology to meet the requirements ofcolloidal stability.22 Themain damaging factor in end-processing and in package isoxygen. The constituents most readily oxidised and whichtherefore act as haze-precursors are the polyphenolic

materials, the anthocyanogens. Techniques of filling bottlesand cans which arc very effective in minimising contact withoxygen are employed in many countries but the Excise

Legislation prevents them being used to utmost advantage inBritain.

The difficulty posed by anthocyanogens is currently dealtwith by treating beer with polyvinyl polypyrrolidonc(PVP).26 The degree of protection obtained depends on the

rate oftreatment afforded. A more radical approach has beento breed barleys which are virtually free ofanthocyanogens.44

However, it is a very lengthy process to develop the new barleys with attractive yield, sufficient disease resistance alongwith the germinative and other properties so necessary formalting. Always, there will be a danger that new races ofparasitic moulds, fungi and mildew will break down thedisease resistance of the variety so that this path can only

be followed alongside a permanent breeding programme.The production of such specialised varieties may be justified in countries where barley is grown specifically for brew

ing. It seems that where brewing provides only one of thelesser uses of barley, as in Britain, the industry in unlikelyto afford the premium that growers would need to justifytheir risk.

For the present, the palliative measures against haze, treatment with proteolytic enzyme, treatment with silica gel,treatment with PVP, should be sufficient for the needs oftrade. In any case the haze-life of beers in small package isalmost invariably much longer than the flavour-life, so that

further improvement will be pointless until longer flavour-lives can be guaranteed.

Flavourspecification and description.Wherever possible science relies on objective measurement and description.The perception and description of flavour by an individual

is inescapably subjective. Application of taste-panels andstatistical treatment of results confers a degree of objectivity.

An early move was to demonstrate the fallibility of individuals using blind tasting in two-glass or three-glass difference tests.4 However, there are no permanent standards ofbeer-flavour so that difference tasting can rarely be used in

routine quality control though it is valuable when specific

Vol.89, 1983] HUDSON: BREWING TECHNOLOGY 193

changes in materials and processing are being investigated.The Flavour Profile technique of tasting and description, is

now in widespread use" and its application has been Facilitated by the adoption of an international list of flavour descriptors." Ideally, such a list should be reinforced with a

collection or library of flavour standards covering every individual descriptive term. It is salutary that there arc approvedreference standards for less than half of the terms listed byEBC/ASBC. Having persuaded the tasters in a panel to usedenned terms the next problem is to get agreement on the

intensity of flavour and, even more difficult, to be consistentin marking, month after month. In this area the problem ofproviding standards seems insurmountable.

Until recently the recording and interpretation of resultshas been almost a greater physical task than the tasting itself.

This task is relieved by the introduction of computer retrieval and calculation so that the panel organiser can now devote his effort to judgement rather than arithmetic. The firststeps have been taken, applying the statistical treatments ofprincipal component analysis and multivariate regressionanalysis, to establish which analytical values are truly ref

lected in flavour and hence are the ones which need to becontrolled.8-9 Hitherto, analyses for bitterness, for dimethylsulphide and perhaps for certain esters are among the fewwhich can be specified to give beneficial flavour. Unfortu

nately it is still the case that far more is known of defectiveflavours than ofsound flavour. It is expected that the statistical researches will correct this imbalance and will reducethe load oftasting to the proper number offlavour characterswhich are susceptible to control.

Distant targets.It is sometimes said mistakenly, thatmalting and brewing are natural processes but such a statement is readily refuted. However, they are processes whichdepend heavily on growth, i.e. on germination of barley in

malting and on reproduction of yeast cells in fermentation.Maltsters and brewers exert great effort in controlling growthbut despite their skills, seasonal and geographic variationscause variation in malt quality. In turn these cause variations

in wort composition and hence in yeast growth and eventually in beer-quality. Despite the increase in knowledge and

improvements in technologies, real anxiety still accompaniesthe introduction of the new seasons materials and a sense ofrelief follows when appropriate adjustments have been made

to ensure consistency in growth and hence in quality. Inaddition the growth of yeast necessitates major processing

to avoid losses of beer.The barley endosperm can be made to generate enzymeswithout the intervention of embryos and systems of fermentation have been proposed in which there is very little multiplication of yeast. A distant target for research will be to

liberate the production ofbeer from its dependence on vegetable growth.

At the meeting in 1916 which marked Horace Brown's 50years of service to Brewing, H. E. Armstrong2 assailed theindustry with the following passage:

*Burton-on-Trent, in the eighteen seventies, probablywas the most active and stimulating scientific centre inthe country, the home of a real biochemistry; vitalproblems were always under discussion. It is sad thatthe scientific life is gone out of the town if not of the

industry and that a group of men so remarkable asPeter Gricss, Horace Brown, Cornelius O'Sullivan andAdrian Brown have no lineal descendants; the lapse isone that is not to the credit of the industry and shouldbe inquired into so that it may be repaired.'The lapse was repaired and the lineal descendants havecontinued in support of the industry at BRF and in other

places.However, to ensure that Brewing continues to attract ablescientists and technologists needed to meet as yet unforeseen

pressures and to lead in biotechnology, it will be necessary

to continue the trust which has yielded such a fruitful expansion in technology through the nineteen seventies.

Acknowledgements.The author is grateful to theFoundation's former Director, Dr A. H. Cook, F. R. S. andpresent Director, Professor B. Atkinson, B.Sc, Ph.D.,

F.l.Chem.E., F. Eng., for guidance, instruction and wisecounsel and to all past and present colleagues who have

made all manner of contribution to the Foundation'sresearches. The latter could not have been so productivewithout the information and co-operation so freely given

from all parts of the industry.

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European Brewery Convention. Proceedings of the 15th Congress. Nice. 1975,243.2. Armstrong, H. E., Journal of'the Institute ofBrewing. 1916,22,

348.3. Beaven, E. S., Journal ofthe Institute ofBrewing. 1934,40,188.4. Bengtsson, K., Wallerstein Laboratories Communications.

1953,16(54), 231.5. Brewers'Guardian, 1981, 110(5), 65.6. Brewing Industry Research Foundation, Journal ofthe Institute

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6th Congress, Copenhagen, 1957,314.15. Hall, R. D. & Evans, J. I., British Patent 1,290,444, (1972).16. Harold, F. V. & Clarke, B. J., Brewers'Digest. 1979, 54(9), 45.

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the 18th Congress. Copenhagen. 1981,421.23. Hudson, J. R., European Brewery Convention. Monograph VII.

Flavour Symposium. Copenhagen. 1981, 7.24. Kirsop, B.H., Journal ofthe Institute ofBrewing. 1974,80,252.

25. Laws, D. R. J., Bath, N. A., Pickett, J. A., Ennis, C. S. &Wheldon, A. G., Journal ofthe Institute ofBrewing, 1977,83,39.26. McFarlane, W. D., Technical Proceedings ofthe 74th Annivers

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