Bilingualer Fachunterricht an berufsbildenden Schulen 

Unterrichtsmodul

Berufsfeld:  	Ernährung/Hauswirtschaft

Beruf: 		Restaurantfachleute
			Hotelfachleute

Tea

ACTION PROGRAMME OF THE EUROPEAN UNION
LEONARDO DA VINCI
PROJEKT NO.: 2002 LA 112 628 BILVOC
Language Competence Through
Bilingual Teaching at Vocational Colleges

Teaching Module

Date of production			09/2005

Subject:					catering		

Topic:					beverage technology

Title: 						tea	

Target Group: 				any group of catering students (first year)

Prior Knowledge:				cocoa

Level of Language Skills:		waystage (A2)

Follow - Ups:		 		coffee

Objectives:		students get an overview on tea

Benefits:		students should be able to answer questions on the following topics: the history of tea,regions where tea is produced, processing the tea leaf to produce black, green and Oolong tea, tasting terminology and tea service

Teaching Module: tea

Teaching Time
(experience)	Contents 
	Activities	Media 	Skills	
10 minutes

15 minutes

60 minutes

15 minutes

60 minutes

20 minutes

20 minutes

	tea at a glance, what do you know about tea

the history of tea 

grades of tea, processing the tea leaves to produce black, green and Oolong tea, regions where tea is produced

grades of tea, processing the tea leaves to produce black, green and Oolong tea

tasting session

summary of contents about tea

evaluation of bilingual teaching/ learning

 	brainstorming/ revision

group work, check unknown words in a dictionary/ wordlist

individual or group work

presentations, classroom discussion

watch leaves, infused leaves and infusion of different kinds of black, green and Oolong teas

lecture

discussion

	board 

transparency/ worksheets

board, worksheets, map

worksheets

board, transparency and
worksheets

worksheets

-

	classroom discussion

using dictionaries, making a timeline

translation and summarizing skills, skills to structure information

presentation skills

tasting skills, note taking skills

note taking

-

	
200 minutes					

Tea

Tea is made from the young leaves and leaf buds of the tea plant, 
Camellia sinensis. Two principal varieties are used, the small-leaved China plant 
(Camellia sinensis sinensis ) and the large-leaved Assam plant 
(Camellia sinensis assamica ).Hybrids of these two varieties are also grown.

History of the tea trade
According to a legend tea has been known in China since about 2700 BC. For millennia it was a medicinal beverage obtained by boiling fresh leaves in water, but around the 3rd century AD it became a daily drink, and tea cultivation and processing began. The first published account of methods of planting, processing, and drinking came in AD 350. Around 800 the first seeds were brought to Japan, where cultivation became established by the 13th century. Chinese from Amoy brought tea cultivation to the island of Formosa (Taiwan) in 1810.Tea cultivation in Java began under the Dutch, who brought seeds from Japan in 1826 and seeds, workers, and implements from China in 1833.
In 1824 tea plants were discovered in the hills along the frontier between Burma and the Indian state of Assam. The British introduced tea culture into India in 1836 and into Ceylon (Sri Lanka) in 1867.At first they used seeds from China, but later seeds from the Assam plant were used.
The Dutch East India Company carried the first consignment of China tea to Europe in 1610.In 1669 the English East India Company brought China tea from ports in Java to the London market. Later, teas grown on British estates in India and Ceylon reached Mincing Lane, the center of tea trade in London By the late 19th and early 20th centuries, tea growing had spread to Russian Georgia, Sumatra, and Iran and extended to non-Asian countries such as Natal, Malawi, Uganda, Kenya, Congo, Tanzania, and Mozambique in Africa, to Argentina, Brazil, and Peru in South America, and to Queensland in Australia.

Classification of teas
Teas are classified according to region of origin, as in China, Ceylon, Japanese, Indonesian, and African tea, or by smaller district, as in Darjeeling, Assam, and Nilgris from India, Uva and Dimbula from Sri Lanka, Keemun from Chi-men in China’s Anhwei Province, and Enshu from Japan.
Teas are also classified by the size of the processed leaf. Traditional operations result in larger leafy grades and smaller broken grades.  The leafy grades are: flowery orange pekoe (FOP), orange pekoe (OP), pekoe (P), pekoe souchong (PS), and souchong (S).The broken grades are: broken orange pekoe (BOP), broken pekoe (BP), BOP fanning, and dust. Broken grades have usually substantial contributions from the more tender shoots, while leafy grades come mainly from the tougher and nature leaves. In modern commercial grading, about 95 percent of production belongs to broken grades, whereas earlier a substantial quality of leafy grades was produced. This shift has been caused by an increased demand for teas of smaller particle size, which produce a quick,
strong brew.

The most important classification is by the manufacturing process, resulting in the three categories of fermented (black), unfermented (green), and semi fermented (Oolong or Pouchong). Green tea is usually produced from the China plant and is grown mostly in Japan, China, and to some extent Malaysia and Indonesia. The infused leaf is green, and the liquor is mild, pale green or lemon-yellow, and slightly bitter. Black tea, by far the most common type produced, is best made from Assam or hybrid plants. The infused leaf is bright red or copper coloured, and the liquor is bright red and slightly astringent but not bitter, bearing the characteristic aroma of tea. Oolong and Pouchong teas are produced mostly in southern China and Taiwan from a special variety of the China plant. The liquor is pale or yellow in colour, as in green tea, and has a unique malty, or smoky flavour.

Processing the leaf
In tea manufacture, the leaf goes through some or all stages of withering, rolling, fermentation, and drying. The process has a twofold purpose: (1) to dry the leaf and (2) to allow the chemical constituents of the leaf to produce the quality peculiar to each type of tea.
The best known constituent of tea is caffeine, which gives the beverage the stimulating character but contributes only a little to colour,  flavour and aroma. About 4 percent of the solids in fresh leaf is caffeine, and one teacup of the beverage contains 60 to 90 milligrams of caffeine. The most important chemicals in tea are the tannins, or polyphenols, which are colourless, bitter-tasting substances that give the drink the astringency. When acted upon by an enzyme called polyphenol oxidise, polyphenols acquire a reddish colour and form the flavouring compounds of the beverage. Certain volatile oils contribute to the aroma of tea, and also contributing to beverage quality are various sugars and amino acids.
Only black tea goes through all stages of the manufacturing process. Green tea and Oolong acquire their qualities through variations in the crucial fermentation stage.

Black tea
Withering
Plucking the leaf initiates the withering stage, in which the leaf becomes flaccid and loses water until, from a fresh moisture content of 70 to 80 percent by weight, it arrives at a withered content of 55 to 70 percent, depending upon the type of processing.
In the traditional process, fresh leaf is spread by hand in thin layers onto trays or sections of coarse fabric called tats. It is then allowed to wither for 18 to 20 hours, depending upon several factors that include the temperature and humidity of the air and the size and moisture content of the leaf. Withering in the open air has been replaced by various mechanical systems. In trough withering, air is forced through a thick layer of leaf on a mesh in a trough. In drum withering, rotating, perforated drums are used instead of troughs, and in tunnel withering, leaf is spread on tats carried by mobile trolleys and is subjected to hot-air blasts in a tunnel. Continuous withering machines move the leaf on conveyor belts and subject it to hot air in an enclosed chamber, discharging withered leaf while fresh leaf is simultaneously loaded.
Mechanized systems greatly reduce withering time, but they can also lower the quality of the final product by reducing the time for chemical withering, during which proteins and carbohydrates break down into simpler amino acids and sugars, and the concentration of caffeine and polyphenols increases.

Rolling
At this stage, the withered leaf is distorted, acquiring the distinctive twist of the finished tea leaf, and leaf cells are burst, resulting in the mixing of enzymes with polyphenols.
The traditional method is to roll bunches of leaves between the hands, or by hand on a table, until the leaf is twisted, evenly coated with juices, and finally broken into pieces. Rolling machines consist of a circular table fitted in the centre with a cone and across the surface with slates called battens. A jacket, or bottomless circular box with a pressure cap, stands atop the table. Table and jacket rotate eccentrically in opposite directions, and the leaf placed in the jacket is twisted and rolled over the cone and battens in a fashion similar to hand rolling. Lumps of rolled leaf are then broken up and sifted. The smaller leaf passing through the sieve - called the fines - is transferred to the fermentation room, and the remaining coarse leaf is rolled again.
In many countries, rolling the leaf has been abandoned in flavour of distortion by a variety of machines. In the Legg cutter (actually a tobacco-cutting machine), the leaf is forced through an aperture and cut into strips. The crushing, tearing and curling (CTC) machine consists of two serrated metal rollers, placed close together and revolving at unequal speeds, which cut, tear, and twist the leaf. The Rotorvane consists of a horizontal barrel with a feed hopper at one end and a perforated plate at the other. Forced through the barrel by a screw-type rotating shaft fitted with vanes at the centre, the leaf is distorted by resistor plates on the inner surface of the barrel and is cut at the end plate. The non-traditional distorting machines can burst leaf cells so thoroughly that in many cases they render the withering stage unnecessary. However, unlike traditional rolling, they do not produce the larger leafy grades of tea.

Fermentation
Fermentation commences when leaf cells are broken during rolling and continues when the rolled leaf is spread on tables or perforated aluminium trays under controlled conditions of temperature, humidity, and aeration. The process actually is not fermentation at all but a series of chemical reactions. The most important is the oxidation by polyphenol oxidise of some polyphenols into compounds that combine with other polyphenols to form orange-red compounds called teaflavins. The teaflavins react with more units to form tearubigins, which are responsible for the transformation of the leaf to a dark brown or coppery colour. The tearubigins also react with amino acids and sugars to form flavour compounds that may be partly lost if fermentations prolonged. In general, teaflavin is associated with the brightness and brisk taste of brewed tea, while tearubigin is associated with strength and colour.
In traditional processing, optimum fermentation is reached after 2 to 4 hours. This time can be halved in fermenting leaf broken by the Legg cutter, CTC machine, and Rotorvane. In skip fermentation, the leaf is spread in aluminium skips, or boxes, with screened bottoms. Larger boxes are used in trough fermentation, and in continuous fermentation the leaf is spread on trays on a conveyor system. In all of these fermentation systems the leaf is aerated by forced air (oxygen being necessary for the action of the enzymes), and it is brought by automated conveyor to the dryer.
Drying
At this stage, heat inactivates the polyphenol enzymes and dries the leaf to a moisture content of about 3 percent. It also caramelises sugars, thereby adding flavours to the finished product, and imparts the black colour associated with fermented tea.
Traditionally, fermented leaf was dried on large pans or screens over fire, but since the late 19th century, heated forced air has been used. A mechanized drier consists of a large chamber into the bottom of which hot air is blown as the leaf is fed from the top on a series of descending conveyors. The dried leaf is then cooled quickly to prevent over drying and loss of quality. Modern innovations on the drier are the hot-feed drier, where hot air is supplied separately to the feeder to arrest fermentation immediately as the leaf is fed, and the fluid-bed drier, where the leaf moves from one end of the chamber to the other over a perforated plate in a liquid fashion.

Green tea
In preparing unfermented tea, the oxidizing enzymes are killed by steam blasting the freshly plucked leaf in perforated drums or by roasting it in hot iron pans prior to rolling. The leaf is then subjected to further heating and rolling until it turns dark green and takes a bluish tint. The leaves are finally dried to a moisture content of 3 to 4 percent and are either crushed into small pieces or ground to a powder.
With the inactivation of polyphenol oxidize, the polyphenols are not oxidized and therefore remain colourless, allowing the processed leaf to remain green. The absence of teaflavins and tearubigins in the finished leaf also gives the beverage a weaker flavour than black tea.

Oolong tea
After a brief withering stage, the leaf is lightly rolled by hand until it becomes red and fragrant. For Oolong it is then fermented for about one half, and for Pouchong for one. Quarter, of the time allowed for black tea. Fermentation is stopped by heating in iron pans, and the leaf is subjected to more rolling and heating until it is dried.

Packaging
Sorting and grading
The first step in packaging tea is grading it by particle size, shape, and cleanliness. This is carried out on mechanical sieves or sifters fitted with meshes of appropriate size. With small-sized teas in demand, some processed teas are broken or cut again at this stage to get a higher proportion of broken grades. Undesirable particles, such as pieces of tough stalk and fibre, are removed by hand or mechanical extractor. Winnowing by air removes dust, fibres, and fluff.

Packing
Teas are packed in airtight containers in order to prevent absorption of moisture, which is the principal cause of loss of flavour during storage. Packing chests are usually constructed of plywood, lined with aluminium foil and paper, and sealed with the same material. Also used are corrugated cardboard boxes lined with aluminium foil and paper or paper sacks lined with plastic.
Blended teas are sold to consumers as loose tea, which is packed in corrugated paper cartons lined with aluminium foil, in metal tins, and in fancy packs such as metalised plastic sachets, or they are sold in tea bags made of special porous paper. Tea bags are mainly packed with broken-grade teas.
Instant tea
Instant teas are produced from black tea by extracting the liquor from processed leaves, tea wastes, or untried fermented leaves, concentrating the extract under low pressure, and drying the concentrate to a powder by freeze-drying, spray-drying, or vacuum-drying. Low temperatures are used to minimize loss of flavour and aroma. Instant green teas are produced by similar methods, but hot water is used to extract liquor from powdered leaves. Because all instant teas absorb moisture, they are stored in airtight containers or bottles.

Preparing the beverage
Blending
Tea sold to the consumer is a blend of as 20 to 40 teas of different characteristics, from a variety of estates, and from more than one country. Price is an important factor, with cheap teas (called fillers) used to round off a blend and balance cost. Blends are often designed to be of good average character without outstanding quality, but distinctive blends - for example, with a flavour of seasonal Ceylon tea or the pungency and strength of Assam tea - are also made.

Brewing

A tea infusion is best made by pouring water just brought to the boil over dry tea in a warm teapot and steeping it from 2 to 5 minutes. The liquor is separated from the spent leaves and may be flavoured with milk, sugar, or lemon.

Tasting
Professional tasters, sampling tea for the trade, taste but do not consume a light brew in which the liquor is separated from the leaf after 5 to 6 minutes. The appearance of both the dry and infused leaf is observed and the aroma of vapour, colour of liquor, and creaming action (formation of solids when cooled) are assessed Finally the liquor is taken into he mouth with a sucking noise, swirled around the tongue, brought into contact with the palate, cheek, and gums, and then drawn back of the mouth and up to the olfactory nerve in the nose before being expectorated. The liquor is thus felt, tasted, and smelled. Tasters have a large glossary of terms for the evaluation of tea, but the less-demanding consumer drinks it as a thirst quencher and stimulant and for the distinctive sour-harsh taste.

Wortsammlung Tee

Deutsch	Englisch	
A		
abkühlen	cool	
Absorbierung	absorption	
Abwesenheit, Fehlen	absence	
Alufolie	aluminium foil	
Aminosäure	amino acids	
anregend	stimulant, stimulating	
Aroma	aroma	
ätherische Öle	volatile oils	
aufbrechen	burst	
aufgegossenes Blatt	infused leaf	
Aufguß	brew	
ausspucken	expectorate	
B		
Bebauung	cultivation	
bedecken	coat	
befestigen	fit	
Behälter, Box	skip	
beibringen	impart	
beitragen	contribute	
Berg	Hügel	
Bestandteile	constituents	
bewegen	revolve	
bezogen auf	according to	
Blatt	leaf	
Blattzellen	leaf cells	
bläuliche Farbe	bluish tint	
bleiben	remain	
Bündel	bunches	
Bündel, Klumpen	lump	
C		
charakteristisch	peculiar	
D		
Dampf	vapour	
deaktivieren	deactivate	
deutliche Biegung	distinctive twist	
Druckdeckel	pressure cap	
Druckluft	forced air	
duftend, aromatisch	fragant	
durchlöchern	perforate	
Durstlöscher	thirst quencher	
E		
einführen	introduce	
einteilen, klassifizieren	classify	
entdecken	discover	
entgegengesetzte Richtung	opposite direction	
entscheidend, heikel	crucial	
Enzyme	enzyme	
erwerben	acquire	
exzentrisch	eccentrically	
F		
Farbe	colour	
Faser(n)	fibre	
Faß	barrel	
fermentiert	fermented	
feste Bestandteile	solids	
fester Stiel	tough stalk	
Feuchtigkeit	humidity	
Feuchtigkeitsgehalt	moisture content	
Flaum, Flocken	fluff	
Fließband	conveyor belt	
flüssig	fluid	
Flüssigkeit	liquor	
fühlen	feel	
G		
Gaumen	palate	
Geruchsnerven	olfactory nerve	
Geschmack	flavour	
Getränk	beverage	
Grenze	frontier	
grobes Material	coarse fabric	
Größe	size	
H		
halbfermentiert	semi-fermented	
heißen Dampf blasend	steam-blasting	
Heißluftgebläße	hot-air	
hier lebhaft:	brisk	
hin und her bewegen	sift	
Hitze	heat	
I		
initiieren, auslösen	initiate	
K		
karamelisieren	caramelize	
Kegel	cone	
Keim, Knospe	bud	
Koffein	caffeine	
Kohlenhydrate	carbohydrates	
komplexe Verbindungen	compounds	
Kreuzung	hybrid	
Kultur	culture	
luftdicht	airtight	
M		
mahlen/zermahlen	grind (ground.-)	
malzig	malty	
mechanisch	mechanical	
mit Luft in Verbindung bringen	aerated	
N		
nach unten gehend	descending	
P		
pflanzen, Pflanze	plant	
pflücken	pluck	
Polyphenole	polyphenols	
Proteine	proteins	
Puder	powder	
R		
rauchig	smokey	
reif	mature	
Reinheit	cleanliness	
riechen	smell	
rollen	roll	
rotieren	rotate	
runder Tisch	circular table	
S		
Saft	juice	
Samen	seed	
Schale, Ablage, Tablett	tray	
Schicht	layer	
Schiefer	slate	
schnell	quick	
schraubenähnlich	screw-type	
Sendung	consignment	
Sieb	sieve/sifter	
Siedlung, Ort	estate	
Sorte, Auswahl	variety	
Sortierer	extractor	
Stärke	strength	
starker Anteil	substantial contribution	
Staub	dust	
Streifen	strip	
streng	astringent	
Stück/Stückchen	piece	
Stufe, Stadium	stage	
Substanzen	substances	
T		
Tannin	tannins	
Tee	tea	
Teilchen	particle	
tragen, beinhalten	bear	
trocknen	dry	
Trog	trough	
Trommel	drum	
Tunnel	tunnel	
U		
übertragen	transfer	
unfermentiert	unfermented	
ungleich	unequal	
unterscheidend	distictive	
Ursprungsregion	region of origin	
V		
Veränderung	shift	
verarbeiten, entwickeln	process	
verbunden	associated	
verdrehen, rollen	distort	
Verkoster	taster	
verlangen	demand	
verursacht durch	caused by	
Vokabular	glossary	
W		
Wange	cheek	
welken	wither	
wellig	corrugated	
Z		
zäh, widerstandsfähig	tough	
Zahnfleisch	gums	
zarter Schössling, Sprosse	tender shoot	
Zucker	sugar	
Zufuhr	feed hopper	
Zunge	tongue	
zurück bleiben	remain	
WORDLIST	TEA	
English	German	
A		
absence	Abwesenheit, Fehlen	
absorption	Absorbierung/Aufnahme	
according	bezogen	
acquire	erwerben	
aerated	mit Luft in Verbindung bringen	
airtight	luftdicht	
aluminium foil	Alufolie	
amino acids	Aminosäure	
aroma	Aroma	
associated	verbunden	
astringent	streng	
B		
barrel	Faß	
bear	tragen, beinhalten	
beverage	Getränk	
bluish tint	bläuliche Farbe	
bottomless circular box	bodenlose runde Schachtel	
brew	Aufguß	
brisk	hier: lebhaft	
bud	Keim, Knospe	
bunches	Bündel	
burst	aufbrechen	
C		
caffeine	Koffein	
caramelize	karamelisieren	
carbohydrates	Kohlenhydrate	
caused by	verursacht durch	
cheek	Wange	
circular table	runder Tisch	
classify	einteilen, klassifizieren	
cleanliness	Reinheit	
coarse fabric	grobes Material	
coat	bedecken	
colour	Farbe	
commence	andauernd	
compound	komplexe Verbindungen	
cone	Kegel	
consignment	Sendung, Lieferung	
constituents	Bestandteile	
contribute	beitragen	
conveyor belt	Fließband	
cool	abkühlen	
corrugated	wellig	
crucial	entscheident, heikel	
cultivation	Bebauung	
culture	Kultur	
D		
deactivate	deaktivieren	
demand	verlangen	
descending	nach unten gehend	
discover	entdecken	
distictive	unterscheidend	
distinctive twist	deutliche Biegung	
distort	verdrehen, rollen	
drum	Trommel	
dry	trocknen	
dust	Staub	
E		
eccentrically	exzentrisch	
enzyme	Enzyme	
estate	Siedlung, Gut	
expectorate	ausspucken	
extractor	Sortierer	
F		
feed hopper	Zufuhr	
feel	fühlen	
fermented	fermentiert	
fibre	Faser(n)	
fit	befestigen	
flavour	Geschmack	
fluff	Flaum, Flocken	
fluid	flüssig	
forced air	Druckluft	
fragant	duftend, aromatisch	
frontier	Grenze	
G		
glossary	Vokabular	
grind(ground.-)	mahlen/zermahlen	
gums	Zahnfleisch	
H		
harsh	hier	
heat	Hitze	
hill	Berg,	
hot-air blast	Heißluftgebläße	
humidity	Feuchtigkeit	
hybrid	Kreuzung	
I		
impart	beibringen	
infused leaf	aufgegossenes Blatt	
initiate	initiieren, auslösen	
introduce	einführen	
J		
juice	Saft	
L		
layer	Schicht	
leaf	Blatt	
leaf cells	Blattzellen	
liquor	Flüssigkeit	
lump	Bündel, Klumpen	
M		
malty	malzig	
mature	reif	
mechanical	mechanisch	
moisture content	Feuchtigkeitsgehalt	
O		
olfactory nerve	Geruchsnerven	
opposite direction	entgegengesetzte Richtung	
P		
palate	Gaumen	
particle	Teilchen	
peculiar	charakteristisch	
perforate	durchlöchern	
piece	Stück/Stückchen	
plant	Pflanze	
plant	pflanzen	
pluck	pflücken	
polyphenols	Polyphenole	
powder	Puder	
pressure cap	Druckdeckel	
process	verarbeiten, entwickeln	
proteins	Proteine	
Q		
quick	schnell	
R		
region of origin	Ursprungsregion	
remain	zurück bleiben	
revolve	bewegen	
roll	rollen	
rotate	rotieren	
S		
screw-type	schraubenähnlich	
seed	Samen	
semifermented	halbfermentiert	
shift	Veränderung	
sieve	Sieb	
sieve/sifter	Sieb	
sift	hin und her bewegen	
size	Größe	
skip	Behälter, Box	
slate	Schiefer	
smell	riechen	
smokey	rauchig	
solids	feste Bestandteile	
stage	Stufe, Stadium	
steam-blasting	heißen Dampf blasend	
stimulant	anregend	
stimulating	anregend, stimulierend	
strength	Stärke	
strip	Streifen	
substances	Substanzen	
substantial contribution	starker Anteil	
sugar	Zucker	
T		
tannins	Tannin	
taster	Verkoster	
tea	Tee	
tender shoot	zarter Schössling, Sprosse	
thirst quencher	Durstlöscher	
tongue	Zunge	
tough	zäh, widerstandsfähig	
tough stalk	fester Stiel	
transfer	übertragen	
tray	Schale, Ablage, Tablett	
trough	Trog	
tunnel	Tunnel	
U		
unequal	ungleich	
unfermented	unfermentiert	
V		
vapour	Dampf	
variety	Sorte, Auswahl	
volatile oils	ätherische Öle	
W		
wither	welken