Caballero B. (ed.) Encyclopaedia of Food Science, Food Technology and Nutrition. Ten-Volume Set

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is generally on ‘hot weight minus 2%’ to accommo-

date evaporative weight loss in the chills. Sometimes

grade will affect price.

0025 Sides are washed and pass into the chill room about

1 h postmortem. Chilling is mandatory. Chilling rates

are determined by carcass weight and fatness and by

air speed and temperature. Faster cooling facilities

throughput and reduces bacterial growth and evap-

orative weight loss, but is more expensive in equip-

ment and energy. Cold toughening may result if

muscle cools below 10



C sooner than 10 h post-

mortem.

Cutting

0026 EC regulations stipulate that, before cutting, sides

must be chilled to below 7



C. A 140-kg side of

average fatness will achieve 7



C in the center hip, in

about 32 h under air of 0



Cat1ms

1

, but this rate

could cause cold toughening in the striploin (long-

issimus dorsi, LD), so a slower chilling may be

required.

0027 Chilled beef sides are quartered according to local

usage, often near the end of the rib cage, and go for

shipping, to the boning hall or retail shops. The

primal cuts of the side differ slightly by country, but

are based on convenient anatomical divisions, eating

quality and costing.

0028 Figure 1 shows London and Home Counties cuts.

Vacuum-packed, usually boneless, primals now pre-

dominate over quarters for distribution.

0029 Beef differs in eating quality depending on the cut,

the age of the animal, and pre- and postmortem

handling. The relative price of sides and cuts depends

chiefly on expected tenderness. Prime 2-year-old steer

is more expensive than 7-year-old culled cow. Fillet

(psoas major) is always tender, and is the most expen-

sive; striploin and rump (gluteus medius) are slightly

tougher, more unpredictable, and are cheaper in cost.

Shin beef is cheapest of all. B. indicus meat is tougher

than that from B. taurus, but breed differences are not

large; reports of tougher bull meat are now attributed

to faster cooling in the leaner sides.

0030 Butchers, and customers, may identify different

cuts, but once the beef is off the bone and trimmed

of fat it is difficult to distinguish lean beef from, for

example, adults of different ages or from fast- and

slow-cooled sides. This has made beef marketing less

transparent than that of other meats.

0031 The trade has developed empirical techniques for

improving quality. Prime beef is from 18–36 -months-

old cattle. Aging, holding in chill for some days,

effects some improvement in tenderness, but will not

make cold-toughened beef as tender as slow-cooled

beef.

0032Muscle biochemistry now provides explanations

for much meat quality variation. In cattle, prolonged

stress premortem depletes muscle glycogen reserves

and postmortem production of lactic acid from glyco-

gen is inadequate to bring the physiological pH of

muscle from 7 to 5.4–5.6, the normal level 48 h

after slaughter. Stressed cattle give meat of above

pH 6.0 that is described as ‘dark, firm, and dry’

(DFD). Consumers react against the darker appear-

ance compared to the customary bright cherry-red

due to oxymyoglobin at pH 5.4–5.6; the higher pH

facilitates microbial spoilage. (See Meat: Structure.)

0033Young bulls, and most cattle in the autumn, are

more prone to stress and thus to produce DFD meat.

Biopsies have shown that depleted muscle glycogen is

not replaced in life for several days after the stress

insult. Stressed cattle must be rested before slaughter.

Humane handling will prevent most DFD meat.

0034Tenderness variation among muscles is partly due

to differences in connective tissue collagen content.

More collagen implies lower tenderness (Table 2(a)).

Decreasing tenderness with age is due to increasing

collagen molecular cross-linking. Solubility is an

inverse measure of cross-linking and is less in older

Topside reverse

Silverside

Eye of round

Aitchbone

Rump

Fillet

(inside)

Striploin

Quarters

divided here

Forerib

Clod

Neck or sticking

Shin

Fore

Brisket

Plate or

F1/4 flank

Flat ribs

Thin flank

Hind

Thick flank

or toprump

Leg

Steakmeat cut into:

leg of mutton cut and

chuck and blade

Middlerib divided into:

backrib and

toprib

fig0001Figure 1 London and Home Counties primal cuts. Adapted

from Gerrard F, Mallion FJ and Quin (eds) (1977) The Complete

Book of Meat. London: Virtue.

BEEF 415

cattle. Table 2(b) shows that extraction, that is, solu-

bility, of collagen falls significantly with increasing

animal age.

0035 Cold toughening seems to invoke two mechanisms.

Early exposure to a temperature of about 10



causes the release of Ca

2þ

ions, which stimulate con-

traction in slack muscles like LD. As the muscle con-

tracts into rigor, extra bonds are formed between the

thick and thin filaments of the contractile myofibrils,

and the strength and toughness of the meat are in-

creased. This is cold shortening, and is confirmed

by micrometry of the sarcomeres, units of the

myofibrils.

0036 Although ultrafast cooling may enhance tender-

ness, normal cold inhibition of protein-splitting

enzymes during the very early period, 2–4 h postmor-

tem, probably causes more tough beef in commerce

than cold shortening. A near-physiological tempera-

ture should be maintained up to 4 h postmortem to

maximize tenderness. Lower temperatures reduce

tenderness pro rata. Subsequent aging at low tem-

perature, and low pH, may not facilitate the splitting

of particular protein links in the myofibrils which

would be critical in providing reentrant cracks for

the breaking of connective tissue during chewing.

(See Meat: Preservation.)

0037 Fillet is always consistently tender because it is low

in collagen, it is stretched giving minimal thick–thin

filament overlap and, being inside the rib cage under

kidney fat, cools slowly.

0038A coherent explanation of beef tenderness is

awaited; the synergy of temperature, pH, and Ca

2þ

concentration in controlling enzyme activity and

shortening is complex, as is the interaction of con-

nective tissue, myofibrils, and cooking.

0039Electrical stimulation (ES) of prerigor carcasses

was patented 40 years ago to improve tenderness.

ES causes muscular contractions, depleting the glyco-

gen and other energy reserves in muscles, so prevent-

ing the cold shortening of slack muscles like LD. It

may toughen muscles if the concomitant fast pH fall

inactivates certain proteolytic enzymes. Its effect may

be compounded by the tearing of opposing simultan-

eously contracting muscles. The New Zealand lamb

industry and the North American beef industry use

ES, but it is not widely used elsewhere.

Nutritional Value

0040Beef is central in most societies for celebrations and

family meals, but has lost a little ground to white

meats recently. Beef is an excellent food, supplying

most nutritional requirements save fiber (Table 3); its

vitamin B

content promotes vitamin absorption

from other sources. The three essential unsaturated

fatty acids account for 3–6% of total fatty acid in

lean beef. Trace elements (iodine, managanese, zinc,

cobalt, selenium, nickel, chromium, molybdenum,

fluorine, vanadium, silicon, arsenic) occur in beef so

a normal diet will ensure an adequate supply. (See

tbl0002 Table 2 Collagen and tenderness

(a) Differences between muscles

Muscle Cut Collagen (%) Tenderness

Psoas major Fillet 2.24 6.7

Longissimus dorsi Striploin 2.76 5.2

Gluteus medius Rump 3.64 4.5

Semimembranosus Topside 4.09 3.3

Semitendinosus Eye of round 4.75 3.6

Biceps femoris Silverside 5.07 2.8

Collagen is expressed as percent fat-free dry matter (Dransfield E (1977) Intramuscular composition and texture of beef muscles.

Journal of the Science of Food & Agriculture 28: 833–842). Tenderness is on a linear scale: 0, extremely tough; 8, extremely tender

(Joseph RL and Connolly J (1977) The effects of suspension method, chilling rates and post mortem ageing period on beef quality.

Journal of Food Technology 12: 231–247).

(b) Collagen cross-linking and age

Extraction

temperature

of medium (



Animalage groups

I (40^49 days) II (403^495 days) III (5 years) IV (10 years)

60 544+29 168+10 82+138+1

70 863+34 409+26 171+482+1

Figures are average +SE mg collagen extracted from samples into medium (Goll DE, Hoekstra WG and Bray W (1964) Age associated changes in bovine

muscle connective tissue. II. Exposure to increasing temperature. Journal of Food Science 29: 615–628).

416 BEEF

Meat: Nutritional Value.) Refer to individual nutri-

ents.

0041 The culinary uses of beef are numberless and it does

not pall. Stock from beef and bones is the ‘fond de

cuisine.’ The beefburger has been universally

accepted by the world’s youth. Charqui (biltong),

sun-dried salted beef, provides protein and salt

throughout the tropics. Salamis were developed to

preserve beef, and other meats with salt and spices;

now thousands of varieties are available. The ‘roast

beef of old England’ still forms the centerpiece of state

banquets. Beef is indeed the universal meat.

See also: Bovine Spongiform Encephalopathy (BSE);

Meat: Structure; Slaughter; Preservation; Nutritional

Value

Further Reading

de Boer H and Martin J (eds) (1978) Patterns of Growth

and Development in Cattle. The Hague: Martinus

Nijhoff.

Dransfield E (1977) Intramuscular composition and texture

of beef muscles. Journal of the Science of Food and

Agriculture 28: 833–842.

FAO (1989) FAO Yearbook of Production, vol. 43. Rome:

Food and Agriculture Organization.

Gerrard F, Mallion FJ and Quin (eds) (1977) The Complete

Book of Meat. London: Virtue.

Goll DE, Hoekstra WG and Bray W (1964) Age associated

changes in bovine muscle connective tissue. II. Exposure

to increasing temperature. Journal of Food Science 29:

615–628.

James SJ and Bailey C (1990) Chilling of beef carcasses. In:

Gormley TR and Zeuthen P (eds) Chilled Foods – the

Ongoing Debate. Amsterdam: Elsevier.

Joseph RL and Connolly J (1977) The effects of suspension

method, chilling rates and post mortem ageing period on

beef quality. Journal of Food Technology 12: 231–247.

Lawrie RA (1985) Meat Science, 4th edn. Oxford: Perga-

mon.

Pearson AM (1981) Meat and health. In: Lawrie RA (ed.)

Developments in Meat Science, vol. 2, ch. 8. London:

Applied Science Publishers.

Tarrant PV (1989) Animal behaviour and environment

in the dark-cutting condition in beef – a review. Irish

Journal of Food Science and Technology 13: 1–21.

Wallis D (1986) The Rare Breeds Handbook. Poole:

Blandford.

Beekeeping See Honey

tbl0003 Table 3 Contribution of 100 g of beef to recommended daily

allowances (RDAs)

Nutrient US RDA From beef %RDA

Energy 11.3 MJ 2.4 MJ 21.0

Protein 56 g 31.1 g 55.5

Calcium 800 mg 22.6 mg 2.8

Phosphorus 800 mg 312.8 mg 39.1

Iron 10 mg 4.7 mg 47.0

Magnesium 350 mg 31.7 mg 9.0

Vitamin A

1000 mgRE 455 mg RE 45.5

Vitamin C 60 mg 1.16 mg 1.9

Thiamin 1.4 mg 0.50 mg 35.7

Riboflavin 1.6 mg 0.43 mg 26.9

Niacin 18 mg 7.95 mg 44.2

Vitamin B

2.2 mg 0.59 mg 26.8

Vitamin B

3.0 mg 5.23 mg 174.3

Folacin 400 mg 17.5 mg 4.4

Zinc 15 mg 7.1 mg 47.3

Copper 2.0–3.0 mg 0.21 mg 10.5

1 retinol equivalent (RE) ¼ 3.3 international units (IU) of vitamin A activity.

BEEF 417

BEERS

Contents

History and Types

Raw Materials

Wort Production

Biochemistry of Fermentation

Chemistry of Brewing

Microbreweries

History and Types

C W Bamforth, University of California, Davis, CA,

USA

The Origins and History of Beer

0001 We must look back to Babylon some 8000 years ago

for the origins of beer. It is assumed that barley, which

was beginning to be cultivated, was found to be both

more nutritious and tasteful once it had been wetted

and subsequently dried after sprouting, Furthermore

the ensuing product, perhaps baked in the form of a

bread, once more wetted and spontaneously fer-

mented by adventitious yeasts, will have been particu-

larly pleasurable. It was soon realized that the dough

could be thinned by the plentiful addition of water

and then strained to remove most of the solids prior

to fermentation of the liquid component in earthen

vats. Furthermore, the ancient brewers will have real-

ized the merits of adding a proportion of the previous

brew to ‘kick-start’ the fermentation. Addition of

certain other plant materials, including mandrake,

afforded flavors to complement the elements of the

brew.

0002 Beer soon became the staple drink of the Egyptian

diet, as well as playing a key role in matters from

currency to religious offering. It is claimed that the

court of the Pharaoh Rameses included a brewery

producing 10 000 hectoliters of beer each year.

0003 Although brewing technology passed to the Greeks

and Romans, beer was only consumed by their lower

classes. In the warmer southern countries wine was

the preferred beverage. The procession of beer-

brewing technology took a more northerly route,

with the Gauls, Germanic tribes, and Celts. In part

this reflected their abilities to work with wood for the

fashioning of vessels for brewing and storage. By the

first century ad there is mention of Britons and

Hiberni (Irish) making an alcoholic drink from barley.

0004Ale was a major beverage for the Danes and Anglo-

Saxons and was regarded as the ideal drink for

heroes. The Vikings drank heartily before setting sail

next day, hence the origins of the phrase ‘three sheets

to the wind.’ The word beer originates from the

Anglo-Saxon bjor.

0005Right the way through and beyond the middle ages,

much beer was brewed in the home, by the female of

the household (the ‘brewster’). However whenever

history has seen the development of larger commu-

nities, it has been accompanied by the establishment

of more substantial, commercial brewing operations.

The development of new technologies also allows

the scaling-up of brewing concerns, and so it was

in the early ad centuries, with individuals learning to

smelt and shape metal into vessels. Cleanable, flame-

proof, heat-conducting copper brewhouse equipment

emerged, and metal could also be used to hold to-

gether ever larger wooden fermenters, as well as

barrels.

0006Through the ages some of the most substantial

breweries have been located in ecclesiastical settings.

Remnants today are the formidable Trappist beers of

Belgium. The Domesday Book (1086) records that

the brewery of St Paul’s Cathedral was producing the

equivalent of some 3150 hectoliters of ale. In every

walk of life, ale was the principal beverage for all

members of the family, young and old.

0007The roots of a truly major commercial brewing

industry in the west were sown first in Bohemia and

Bavaria. The importance of good malt to good beer

was recognized, causing the development of specialist

malthouses. Many of the European beers were

flavored and preserved with proprietary mixtures of

herbs and spices, including bog myrtle, coriander,

cumin, and even strychnine. Such mixtures were

known as gruit. Hops were first used in beer in Bav-

aria in the late eighth century, yet did not gain the

ascendancy as the flavorant for several centuries in

many countries, notably England. The term ‘ale’ was

originally retained in that country for description of

418 BEERS/History and Types

products that did not contain hops, as opposed to

beers, which did.

0008 Until the sixteenth century ale (in later years in-

corporating hops) was the major beer style univer-

sally, such beers being produced in open vessels by

yeasts that rose to the surface during fermentation

(top fermentation). Bottom fermentation probably

started in Bavarian monasteries in the early sixteenth

century. A major factor was an edict of Prince Max-

imilian I in 1533 that largely precluded brewing in the

summer months. The ale-style products from top fer-

mentation had been brewed in warm conditions, but

now bottom fermentation was performed in the

winter, with the beer being stored (‘lager’ ¼ ‘store’)

until the subsequent autumn, when brewing could

start again.

0009 In Bavaria in 1516, Dukes Wilhelm IV and Ludwig

X introduced the Reinheitsgebot to preclude the use

of undesirable materials in brewing, a practice that

had crept in due to shortages of barley and hops. The

law has survived to this day and now extends

throughout Germany for domestic production, re-

stricting the raw materials of brewing to malt, hops,

yeast, and water.

0010 James I of England, whose exchequer took four

pence for every quarter of malt, levied the first tax

specifically on brewers in 1614.

0011 Just 6 years later the first ales were landed in the

New World with the Pilgrim Fathers, who actually

put into Plymouth Rock because: ‘We could no longer

take time for further search or consideration, our

victuals being much spent, especially our beer.’

0012 In the late eighteenth century, with the Industrial

Revolution, there was a decline in the proportion of

beer brewed at home and a growth in brewing com-

panies producing beer for consumption for a working

population. The development of transportation

systems enabled the increasingly growing brewing

companies to distribute their products ever more

widely. The railways and roads were fast becoming

main arteries for beer distribution, but beer was also

being shipped internationally, with products such as

the India Pale Ale from England having a suitable

long shelf-life, its high hopping acting as a preserva-

tive. Use of James Watt’s steam engines (1765) within

the brewery facilitated increased efficiencies and out-

puts. The development of artificial refrigeration by

von Linde (1876) divorced the production of lager-

style products from an association with natural ice

such as was to be found in the winter months adjacent

to the great lakes in North America, as well as

allowing the shipping of beer ever greater distances

in cold railcars.

0013 The ability to regulate the process was, by now,

manifest. In 1762 Michael Combrune had employed

a thermometer to enable the checking and regulation

of temperatures in the mash tun and fermenter. Prior

practice was to dip the thumb into the brew to ensure

that the wort wasn’t too hot for the yeast – the ‘rule of

thumb.’ Another Englishman, John Richardson, fur-

ther facilitated enhanced process control with the

construction in 1784 of the first brewer’s saccharom-

eter. Other significant technological developments in-

cluded Pasteur’s understanding (1860) of the natural

spoilage of foodstuffs by microorganisms and the

role of heat in countering this, as well as the develop-

ment of bottle-closing technology, the crown cork.

This was invented in Baltimore by William Painter, a

man of British descent who accordingly took out his

first patent on closures in London in 1885 and who,

by 1891, had arrived at the familiar crimped metal

device. Accordingly, beer for domestic consumption,

as opposed to draught beer for retail in pubs and bars,

could now reach a vast hinterland. The appearance of

beer had been revolutionized by Enzinger’s (1879)

introduction of filtration while the consistency of

beer was dramatically enhanced by Hansen’s realiza-

tion in 1883 of the importance of using isolated,

pure yeast strains for fermentation of individual

beers. The advent of cylindroconical vessels through

the patents of Nathan filed between 1899 and 1905

allowed the large-scale fermentation of beer. The first

cans suitable for filling with beer were produced

by the American Can Company in 1934, and the

initial company to go ahead with a canned product

was Krueger’s of Newark with its cream ale, in

January 1935.

0014Other key developments in the evolution of a re-

fined brewing process were the establishment of

breeding programs for the key raw materials barley

and hops. The first named barley variety came in

1823 in the UK through the skill of Chevalier, and it

was duly named for him. The first established hop-

breeding program was also in the UK, with Howard

at Wye, commencing in 1904. By the 1950s for barley

and 1970s for hops the most significant advances in

how to process them had been put in place. Thus the

importance of steeping barley intermittently with air

rests between water soaks had led directly to a

halving of total malting time and huge enhancement

of output and efficiency. For hops, the establishment

of pellet technology and, later, extraction of the key

principles using liquid carbon dioxide allowed en-

hanced utilization of resins and oils and flexibility of

product design.

Styles of Beer

0015One of the most fundamental approaches to classify-

ing beers is based on whether they are produced by

BEERS/History and Types 419

‘top fermentation’ or ‘bottom fermentation,’ which

basically refers to whether the yeast congregates at

the top of the vessel or sinks to the base. With modern

cylindroconical fermenters and their high hydrostatic

pressures there tends to be less of a distinction.

0016 Top fermentation, with its vastly older pedigree,

tends to be performed at relatively warm tempera-

tures (15–25



C), under which conditions yeast tends

to produce higher levels of flavor volatiles such

as esters, affording fruity characteristics. Bottom-

fermentation beers are produced at much lower

temperatures (say 6–15



C) and frequently possess

significant sulfury notes.

Top-Fermentation Beers

0017 Ales Perhaps the major product in the genre is the

English pale ale, which is referred to as bitter when

dispensed on tap (draught). Alcohol content will be in

the range 3–7.5% by volume (ABV). Classically it is

produced from well-modified malt, kilned to a rela-

tively high-temperature regime to impart a copper

color. The products are relatively malty, especially in

the case of Scotch ales, which may be sweeter and

darker than their English counterparts. After fermen-

tation ales are traditionally primed with extra sugars,

‘dry-hopped’ with a handful of cones and dosed with

isinglass finings prior to racking in casks. Residual

yeast uses the sugars to introduce natural carbonation

(albeit at a low level of perhaps 2.5 g l

1

), prior

to being sedimented along with other insolubles by

the finings. The product is not pasteurized and is

distributed for retail in pubs, whether by gravity dis-

pense or hand-pumping via a beer engine. Because of

the skill needed to deal with cask ales (if infections

and clarity problems are to be avoided), it has become

increasingly common for such ales to be conditioned

in the brewery and pasteurized prior to packaging in

keg (for draught dispense) or bottle or can. Such

products have a carbon dioxide similar to that of

other beers sold from kegs or small packs, between

4.5 g l

1

for large packs and up to 6 g l

1

for small

packs. Lower carbonation products in both keg and

small packs have become increasingly prevalent over

the past decade. They incorporate nitrogen gas,

which enhances foam stability and also affords a

smooth texture to the product. Because of the greatly

reduced tendency for foam to form at the lower car-

bonation levels, it is common to use nucleation

devices called ‘widgets’ in cans and even bottles con-

taining beer of this type.

0018 Mild ale, a style which is in decline and largely

perceived as old-fashioned, is a sweeter, darker prod-

uct, the color being either due to caramel or in part to

a low proportion of heavily kilned malt, though not

so much as to impart burnt flavors. It tends to have a

lower alcohol content (less than 3.5% ABV) and

when bottled may be referred to as brown ale. Trad-

itional terms in Scotland have been heavy, for their

stronger bitters, and light, for the milds.

0019Barley wines are fermented at very high gravities

(the higher the specific gravity, the greater the content

of sugars available for fermentation), which is an

additional factor impacting on the very high ester/

fruity character and, of course, accounting for a

very high alcohol content of up to 10% ABV. They

are usually sold in smaller volumes, in bottles called

nips.

0020Porter In early eighteenth-century London there

were three main categories of beer: ale, which was

strong, the weaker beer, and two-penny, a better

quality of beer. There were brown, pale, and amber

versions of each. People tended to ask for ‘half and

half’–equal measures of ale and beer – or ‘two-

thirds’–(three threads): ale, beer and ‘tuppenny’ in

equal measure. One far-sighted brewer in 1722 con-

ceived of a product based on the second of these but

with the three styles premixed in the brewery, and as a

consequence saving the landlord’s time. Because most

of the customers wanting their beer in a hurry were

porters in the local markets, it became known as

porter. There are few, if any, genuine porters to be

had these days. They are traditionally very dark, due

to the use of roasted barley, and not overwhelmingly

strong (about 5% ABV).

0021Stout A close relative of porter, stout originated in

Ireland, of course, with intense color and burnt,

smoky flavors due to the use of roasted barley ad-

juncts and high bitterness. These robust flavor char-

acters have been tempered for many years now by the

use of nitrogen gas, which ‘smoothes’ the palate as

well as affording the rich, white, and creamy foam.

Alcohol content may be between 4 and 7%, with up

to 10% in imperial stouts. Sweet stouts are a British

variant, of lower alcohol content (up to 4% ABV),

with less roast character (often due to the use of

caramel and less roast barley as colorant).

0022Belgium top-fermentation beers There is a greater

diversity of beer styles in Belgium than any other

country. Trappist beers are relatively dark, intensely

bitter, acidic products of up to 12.5% ABV, with clear

fruity notes. The Lambic and Gueuze products pos-

sess a diversity of complex flavor characteristics,

imparted through the agency of the metabolic activ-

ities of a more complex microflora than brewing yeast

alone. They tend to be quite sour (low pH) and are

frequently not clear. Various flavorants may be added

420 BEERS/History and Types

to certain Belgian beers, including cherries (Kriek) or

raspberries (Framboise).

0023 German ales Alt from the German means ‘old,’ is

brewed ‘in the old way’ from a grist of barley and (to

a lesser extent) wheat malts. It is a dark-copper color,

relatively bitter, and approximately 5% ABV. Kolsch,

from Cologne, is a much lighter beer, of similar alco-

hol content. The darker malts used in the production

of alt are replaced by a less intensely kilned malt,

called Vienna malt.

0024 German wheat beers Weizenbier is made from a

grist comprising at least 50% wheat malt. The prod-

ucts are relatively highly carbonated, affording a re-

freshing character alongside the fruity and phenolic

(clove-like) characters. Kristallweizen denotes that

the beers have been filtered to remove yeast, whereas

Hefeweizens are cloudy due to yeast, which is trad-

itionally employed to carbonate the bottled product

through ‘natural conditioning.’ The products are rela-

tively lightly colored (straw-like) and have alcohol

contents of 5–6% ABV. Weissbier (‘white beer’)is

much weaker (e.g., 2.8% ABV), and made from a

grist of less than 50% wheat malt, with the addition

of lactic acid bacteria to generate a low pH of 3.2–

3.4. Accordingly such beers are quite sour, and may

be taken with raspberry or sweet woodruff syrups.

Bottom-fermentation beers

0025 The classic style originated in mid nineteenth-century

Bohemia, in the Pilsen city brewhouse. It is quite a

malty brew (the malt traditionally being relatively

undermodified), typically with 4.8–5.1% ABV and a

pale gold color. Particularly prized is the late hop

character, afforded by retaining a proportion of the

hops for addition late in the kettle boil to ensure that

the desired fraction of essential oils presents.

0026 All too often the term lager is used synonymously

with pilsner (pils). Lager as a term is really an um-

brella description for all relatively pale brews, fer-

mented and dispensed at low temperatures.

0027 The greatest breadth of styles of this type of

product is to be found in Germany. To many the

distinction between some of the styles is subtle and,

for those seeking to replicate them internationally,

may own as much to marketing as to major differ-

ences in brewing practice.

0028 Export is a little stronger than Pilsner (5.5% ABV)

and darker, though somewhat less bitter.

0029 Bock is a stronger beer (6–8% ABV) with sulfury

and malty flavors and colors ranging from straw to

dark brown. The related Doppelbock may contain up

to 12% ABV.

0030Marzen (‘March beer’) was historically brewed to a

high strength (up to 6.5% ABV) with pale and dark

versions. It has ‘middle-of-the-road’ characters, with

some toasted notes.

0031Helles (4.5–5.5% ABV) is pale amber, very malty,

with a low bitterness and hop character.

0032Dunkel has a similar alcohol content but is copper-

brown, whilst Schwarzbier is black, dry, and between

3.8 and 5% ABV.

0033Malt liquor is a term used to describe alcoholic

products (6–7.5% ABV) which are very pale, very

lightly hopped and quite malty and sweet, and origin-

ating in the USA.

0034The other lager-style product indigenous to the

USA is steam beer. The origins of this product can

be traced to the California gold rush and a demand

for light and refreshing drinks despite the unavail-

ability of ice for cold storage and conditioning.

Bottom yeasts were used at warmer fermentation

temperatures in shallow vessels into which the

‘steaming’ wort was introduced to cool.

Other classifications of beer

0035There is considerable blurring of the boundaries that

divide the classic beer styles. For example, products

both light and dark have been developed with all

manner of additional flavors, such as citrus character,

cf. the traditional mixers of ale with lemonade

(shandy) or lager with a splash of lime or lemon

(lager top). Flavors as diverse as oyster, chocolate,

coriander, and chilli have been used. Black lagers

have been developed, as indeed have colorless ones.

There is probably no limit to the ingenuity of new

product development teams, although most of these

products tend to be quite short-lived as brands.

0036Ice beers The original provenance of this style stems

from the trick (mostly in Canada) of concentrating

beer by placing it on the window sill in the heart of

winter, under which conditions water freezes out first,

leaving a more alcoholic and warming solution

behind. In fact, the freeze concentration technique

used in the manufacture of such beers in the brewery

produces ice in only sparing amounts, but there is a

loss of some of the tannin materials, which may make

these products slightly less astringent than the norm.

0037Dry beers These are lagers with a relatively low

proportion of residual sugars making for a low sweet-

ness. They are related to the light beers, the most

rapidly growing genre. Standard beers contain a pro-

portion of carbohydrate surviving the fermentation

process, whereas a light beer has most or all of this

sugar converted. These beers therefore have fewer

BEERS/History and Types 421

calories, provided that the extra alcohol is diluted to

the level found in ‘normal’ beers. They are produced

using a more convoluted mashing procedure to allow

as much starch conversion as possible, followed by

the use of malt extracts (or microbial enzymes if the

brewer is content to use additives) in the fermenter.

0038 Draft beers The term ‘draft’ (‘draught’) is nowadays

used not only to describe large pack dispense (keg,

cask) but also nonpasteurized beers in small pack.

0039 Non- and low-alcohol beers There are many defin-

itions worldwide about what constitutes low-alcohol

products. Perhaps the most stringent is in the UK,

where non- and low-alcohol beers contain less than

0.05% or 1.2% ABV respectively. They are produced

either by removing the alcohol from a full-strength

brew, by techniques such as vacuum distillation or

reverse osmosis, or by restricting the ability of yeast

to ferment wort, either by making a wort containing

very low levels of fermentable sugars or by ensuring

that the contact between yeast and wort is at a very

low temperature and for a relatively brief time.

See also: Beers: Biochemistry of Fermentation

Further Reading

Bamforth C (1998) Beer: Tap into the Art and Science of

Brewing. New York: Insight.

Corran HS (1975) A History of Brewing. Newton Abbot:

David and Charles.

Raw Materials

P Hughes, Heineken Technical Services,

Zoeterwoude, The Netherlands

Background

0001 The production of beer has a long history, dating

back to the Sumerians and the Egyptians. A unique

beverage, the quality of beer is substantially depend-

ent on the identity and quality of its raw materials.

The major raw materials of beer are cereals and hops.

Both have a number of roles in beer production and

final beer quality, but the cereals principally provide

sugars and amino acids for fermentation. Hops are

used to provide a unique flavor and to stabilize the

beer foam. Both can be processed for optimal and

more flexible usage for beer production. Here, aspects

of hops, and cereals as they pertain to the brewing

industry, are described. For clarity, brewing specific

terms are defined in Table 1.

Hops

0002The cultivated hop (Humulus lupulus L.) was origin-

ally added to beers during their production for flavor

and to extend the beer shelf-life. Historically, herbs

have also been used, but today, essentially only the

hop is used commercially. Hops are cultivated solely

for beer production and grow almost exclusively

in the temperate regions of the world, between the

latitudes of 35 and 55



, both north and south of

the equator. Owing to continuing improvements in

the utilization of hops and the gradual reduction of

beer bitterness levels, the global production of hops is

currently decreasing (Table 2), whereas beer produc-

tion is increasing on a world-wide basis.

0003The hop plant is a hardy, climbing, herbaceous

perennial plant. The rootstock stays in the ground

from year to year. The vines that grow from the

rootstock are not self-supporting, and the provision

of a support structure or wirework is a significant

capital investment when setting up a hop garden.

Traditionally, hop plants attained heights in the

region of 5 m, but the recent development of commer-

cial dwarf varieties (c. 2.5 m in height) allows more

cost-effective supporting structures such as hedges to

be used.

Hops for Beer Production

0004The brewing value of the hop is embodied in its cones.

These are structures that bear small, physically robust

yellow lupulin glands. It is these glands that contain

the hop essential oil and the hop acids that are respon-

sible for hoppy and bitter flavors, respectively. Trad-

itionally, cones were added to the wort boil, during

which time extraction and chemical conversion of the

appropriate brewing value occurs. However, neither

the extraction nor chemical conversion is particularly

efficient during a typical beer production process, and

an industry has grown up, whereby hop cones are

processed to enhance efficiency, or utilization, of this

raw material. Today, around 85% of all hop products

used are either extracts (45%) or pelleted hops (40%).

The remainder is made up of reduced extracts and the

unprocessed hop cones themselves (Table 3). These

various products are used at a number of stages

during beer production (Figure 1).

Hop Pests and Diseases

0005These are numerous and can have widespread effects

on the resulting crop. The sensitivity of hops to vari-

ous pests and diseases is in some cases dependent on

422 BEERS/Raw Materials

variety, so that breeding programs, such as those at

the Hop Research Unit at Wye College, specifically

test for resistance to a range of challenges as part of its

selection criteria. For instance, resistance to verticil-

lium wilt, endemic in some parts of the UK, is essen-

tial here for acceptance to the grower.

The Hop Market

0006 Hop producers rely almost solely on brewers to pur-

chase their product. In previous years, the suscepti-

bility of the hop crop to a range of pests and diseases

has affected their market price. This resulted in the

practice of the forward contract, whereby a grower or

merchant would undertake to supply certain quan-

tities of hops or hop products to a buyer for a given

period. Hops that were not put aside for forward

contracts were sold on the spot market. At the end

of the 1990s, the hop industry suffered from overpro-

duction, so hops and hop products were available for

unprecedented low prices on the spot market, and

forward contracts became unpopular. Many growers,

particularly in Europe, ceased growing what became

an uneconomical crop. The cost of the infrastructure

to grow hops and the need for two to three seasons

before a high-quality crop can be expected mean that

there will be an inertia for farmers to turn back to

hops. At the beginning of the new millennium, the

reductions in acreage worldwide have begun to

redress the supply and demand balance.

Impact on Beer Production and Quality

0007The use of hops in brewing is famous for the provi-

sion of bitterness in the final beer. However, they have

a number of other effects on the final beer quality and

on the production process itself.

tbl0003Table 3 Distribution of global hop sales

Hop product class Proportion of

totalsales (%)

Comments

Cones 7 Traditional. Use declining

Bittering pellets 19 Enhanced control of

bitterness

Aroma pellets 22 Enhanced control of hoppy

aroma

Extracts 44 Highly concentrated aroma/

bitter products

Reduced extracts 8 Chemically modified by

selective reduction

tbl0001 Table 1 Definitions of common malting and brewing terms

Term Definition

Boiling Operation that follows lautering. The sweet wort is boiled to ensure its sterilization. a-Acids added with hops or hop

products are partially isomerized here, and there is also substantial development of solids that are later removed.

Yeast is added to the cooled product to begin fermentation.

Fermentation Yeast added to the cooled boiled wort uses the sugars, free amino acids and residual lipid present to grow and

generate ethanol.

Lautering A common process in many breweries. The mash is allowed to run through a coarse slotted plate. Insoluble husk

material settles on to this plate and creates an effective filter bed.

Malting Process of partial germination to convert barley (or, less commonly, wheat) into malt.

Modification In terms of malt, this indicates the degree of biopolymer degradation in the grain.

Pasteurization Commonly applied operation that neutralizes any residual bacteria in the final product by controlled heating. Some

companies prefer to sterile filter their product.

Run-off Refers to the gravitational separation of malt extract (wort) from residual solids, usually during the lautering

operation. This can be seriously hampered by a number of wort constituents, such as b-glucan gums.

Trub Solids formed during wort boiling and subsequent cooling. Mainly composed of protein–polyphenol complexes.

Utilization Traditionally refers to the ratio of the moles of bitter iso-a-acids recovered in the final beer to moles of a-acids added

to the wort boil. Now often modified to include efficiency of isomerized hop product dosing.

Wort (sweet) The liquid that recovered, for instance after lautering. The term ‘sweet’ refers to the high levels of fermentable

sugars that are released during the mashing operation. The addition of hops at wort boiling gives a bitter wort.

Whirlpool A common device in breweries for effective solids removal from hot boiled wort. Wort is passed into the whirlpool

vessel tangentially, and the solids present accumulate at the center and deposit as a cone at the base of the

vessel.

tbl0002 Table 2 Global production of hops

Country Globalproduction (percentage of globalproduction)

By area (hectares) By mass (tonnes)

Germany 18 600 (31.5) 29 290 (30.3)

USA 14 630 (24.8) 30 650 (31.7)

Czech Republic 6 110 (10.4) 4 890 (5.1)

China 4 930 (8.4) 13 000 (13.5)

Poland 2 250 (3.8) 3 060 (3.2)

England 1 980 (3.4) 2 800 (2.9)

Slovenia 1 620 (2.7) 1 760 (1.8)

Russia 1 520 (2.6) 820 (0.8)

Total 59 020 (100) 96 610 (100)

Source: The Barth Report (2000/2001).

BEERS/Raw Materials 423

0008 Bitterness Most, if not all, of the bitterness of beer is

due to the presence of the iso-a-acids. These are a

mixture of six major components, which are three

stereoisomeric pairs of compounds derived from

each of the three hop a-acids (Figure 2). These

a-acids are isomerized to the iso-a-acids during the

wort boiling stage, although in practice, the final

utilization is around 30–40%. In contrast, isomeriza-

tion by hop processing gives yields in excess of 90%.

There are probably minor differences in the bitterness

of the individual compounds. Nevertheless, whilst

hops come in a wide range of varieties, current think-

ing is that variety has little effect on bitterness inten-

sity or quality. High-a-acid hop varieties have become

a lucrative breeding target, because of the generally

favorable yields of a-acids per hectare. Today, a-acids

are considered a commodity on the hop market.

There are some who consider the cohumulone con-

tent of the a-acids to have a poorer-quality bitterness,

but to date, this has not been conclusively demon-

strated.

0009Hops also contain the b-acids. Although these do

not undergo isomerization in the sense of a-acids,

they do form bitter degradation products – the hulu-

pones – when present during wort boiling (Figure 3).

In practice, this contribution to bitterness is usually

minor.

0010Hoppy flavor Hop cones have a characteristic

aroma, which is particularly evident when hops are

rubbed between the hands. This is due to the presence

of over 300 volatile compounds in the essential oil of

hops. In addition to volatility, some hop oil com-

pounds are chemically reactive, so that after wort

boiling, very little of the original hop aroma com-

pounds remain, with some being lost completely.

Nevertheless, what is left, subject to the impact of

fermentation, stays in the beer to give a unique flavor.

Beers vary substantially in the intensity and quality of

their hoppy flavor. The intensity is dependent on

the brewing practice and dosing level, whereas the

quality is mostly dependent on the varieties used

fig0002 Figure 2 Isomerization of a-acids to the bitter iso-a-acids. The

mechanism of the reaction is unclear, but the result is a ring

contraction and the production of cis- and trans-isomers. R repre-

sents isopropyl, isobutyl, or sec-butyl substituents. R

and R

are

either hydroxyl or 4-methylpen-3-enoyl, depending on whether a

cis-ortrans isomer is formed.

fig0003Figure 3 Degradation of hop b-acids to bitter hulupones. This

reaction is far from quantitative, although it is believed by some

to impart a good-quality bitterness to the final product. See

Figure 2forthedefinitionofR.

α-products

isomerized pellets

base extract

chemically-modified

hop bitter acids

isomerized extracts

chemically-modified

hop bitter acids

isomerized extracts

ρ-iso-α-acids

aroma pellets

oil-rich extracts/

emulsions

high quality

extracts/essences

pelleted cones

Kettle

Pitching wort

Post-fermentation

Post-filtration

In cask

fig0001 Figure 1 Points-of-addition of hops and hop products during beer production. Generally, the boiling stage is mandatory if

isomerization of the a-acids is necessary.

424 BEERS/Raw Materials