Tea Fermentation

8/13/2019 Tea Fermentation

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] Fermentation is a tea production style in which the tea leaves undergo

microbial fermentation and oxidation after they are dried and rolled.

ProcessingAfter picking appropriate tender leaves, the Plucked leaves are handledgingerly to prevent bruising and unwanted oxidation. Weather permitting, the

leaves are then spread out in the sun or a ventilated space to wilt and remove

some of the water content.!"] #n overcast or rainy days, the leaves will be

wilted by light heating, a slight difference in processing that will affect the

$uality of the resulting maocha and pu%er. &he wilting process may be skipped

altogether depending on the tea processor.

&he leaves are then dry pan'fried using a large wok in a process called (kill

green( ) * pinyin+ sh $-ng, which arrests most en/yme activity in the leaf

and prevents full oxidation. After pan'frying, the leaves are rolled, rubbed, and

shaped into strands through several steps to lightly bruise the tea and then

left to dry in the sun. 0nlike green tea produced in china which is dried with

hot air after the pan'frying stage to completely kill en/yme activity, leaves

used in the production of pu'erh are not air'dried after pan'frying, which

leaves a small amount of en/ymes which contribute a minor amount of

oxidation to the leaves during sun'drying. &he bruising of the tea is also

important in helping this minimal oxidation to occur, and both of these steps

are significant in contributing to the uni$ue characteristics of pu'erh tea. #ncedry, maocha can be sent directly to the factory to be pressed into raw pu%er,

or to undergo further processing to make ripened pu%er.!1] 2ometimes 3ao

4ha is sold directly as loose'leaf (raw( 2heng 4ha or it can be matured in

loose leaf form, re$uiring only two to three years due to the faster rate of

natural fermentation in an uncompressed state. &his tea is then pressed into

numerous shapes and sold as a more matured (raw( 2heng 4ha.

5ipe pu'erhedit]

(5ipened( 2hou 4ha ) tea is pressed maocha that has been specially

processed to imitate aged (raw( 2heng 4ha tea. Although it is also known in

6nglish as cooked pu'erh, the process does not actually employ cooking to

imitate the aging process. &he term may come be due to inaccurate

translation, as sh7 ) means both (fully cooked( and (fully ripened(.

&he process used to convert m8och8 into ripened pu%er manipulates

conditions to approximate the result of the aging process by prolonged

bacterial and fungal fermentation in a warm humid environment under

controlled conditions, a techni$ue called W9 :;i ) , (wet piling( in 6nglish,

which involves piling, dampening, and turning the tea leaves in a mannermuch akin to composting.


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&he piling, wetting, and mixing of the piled m8och8 ensures even

fermentation. &he bacterial and fungal cultures found in the fermenting piles

were found to vary widely from factory to factory throughout oxidation process can result in bad ripened pu%er, characteri/ed

by badly decomposed leaves and an aroma and texture reminiscent of

compost. &he ripening process typically takes anywhere from half to a whole a

year. For example, a ripened pu%er produced in early "??= will be pressed in

the winter of "??=>"??@, and appear on the market between late "??@ and

early "??.

&he W9 :;i process was first developed in !BC! by 3enghai &ea Factory]

and Dunming &ea FactoryC] to imitate the flavor and color of aged raw pu'erh,

and was an adaptation of wet storage techni$ues used by merchants to

artificially simulate ageing of their teas. 3ass production of ripened pu%er

began in !BC. Et can be consumed without further aging, or it can be stored

further to (air out( some of the less savory flavors and aromas ac$uired

during fermentation. &he tea is sold both in flattened and loose form. 2ome

tea collectors believe (ripened( 2heng 4ha should not be aged for more than

a century.Pressingedit]

A pu'erh tea factory, which steams, bags, and presses the loose leaf pu'erh

into tea bricks

&o produce pu%er, many additional steps are needed prior to the actual

pressing of the tea. First, a specific $uantity of dry m8och8 or ripened tea

leaves pertaining to the final weight of the bingcha is weighed out. &he dry

tea is then lightly steamed in perforated cans to soften and make it more

tacky. &his will allow it to hold together and not crumble during compression.

A ticket, called a (ni fGi( ) or additional adornments, such as colored

ribbons, are placed on or in the midst of the leaves and inverted into a cloth

bag or wrapped in cloth. &he pouch of tea is gathered inside the cloth bag and

wrung into a ball, with the extra cloth tied or coiled around itself. &his coil or

knot is what produces the dimpled indentation at the reverse side of a tea

cake when pressed. :epending on the shape of the pu%er being produced, a

cotton bag may or may not be used. For instance, brick or s$uare teas often

are not compressed using bags.!@]

Pressing can be done by+


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A press. En the past hand lever presses were used, but were largely

superseded by hydraulic presses. &he press forces the tea into a metal form

that is occasionally decorated with a motif in sunken'relief. :ue to its

efficiency, this method is used to make almost all forms of pressed pu%er. &ea

can be pressed either with or without it being bagged, with the latter done byusing a metal mould. &ightly compressed bHng, formed directly into a mold

without bags using this method are known as tiI bHng ) , literally (iron

cake>puck( due to its density and hardness. &he taste of densely compressed

raw pu%er is believed to benefit from careful aging for up to several decades.

A large heavy stone, carved into the shape of a short cylinder with a handle,

simply weighs down a bag of tea on a wooden board. &he tension from the

bag and the weight of the stone together give the tea its rounded and

sometimes non'uniform edge. &his method of pressing is often referred to as+

(hand( or (stone'pressing(, and is how many artisanal pu%er bHng are still

manufactured.

Pressed pu%er is removed from the cloth bag and placed on latticed shelves,

where they are allowed to air dry, which may take several weeks or months,

depending on the wetness of the pressed cakes.!"] &he pu%er cakes are then

individually wrapped by hand, and packed.

4lassificationedit]

Aside from vintage year, pu%er tea can be classified in a variety of ways+ by

shape, processing method, region, cultivation, grade, and season.2hapeedit]

Pu%er is compressed into a variety of shapes. #ther lesser seen forms include+

stacked (melon pagodas(, pillars, calabashes, yuanbao, and small bricks )"J@

cm in width. Pu%er is also compressed into the hollow centers of bamboo

stems or packed and bound into a ball inside the peel of various citrus

fruits.Emage 4ommon name 4hinese characters Pinyin :escription

2 &

King, Keeng, 4ake, or :isc KHngch8 A round, flat, disc or puck'

shaped tea, the si/e ranges from as small as !??g to as large as @ kg or more,

with 1@Cg, =??g, and @??g being the most common. :epending on the

pressing method, the edge of the disk can be rounded or perpendicular. Et is

also commonly known as L-/M bHngch8 ), literally (seven units cake tea(

because seven of the bing are packaged together at a time for sale or

transport.

&uocha, Kowl, or Nest &uOch8 A convex knob'shaped tea, its si/e

ranges from 1g to 1 kg or more, with !??g, "@?g and @??g being the most

common. &he name for tuocha is believed to have originated from the round,

top'like shape of the pressed tea or from the old tea shipping and tradingroute of the &uo 5iver.!] En ancient times, tuocha cakes may have had holes


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punched through the center so they could be tied together on a rope for easy

transport.

Krick hunch8 A thick rectangular block of tea, usually in

!??g, "@?g, @??g and !???g si/es* huancha bricks are the traditional shape

used for ease of transport along the ancient tea route by horse caravans.2$uare Fngch8 A flat s$uare of tea, usually in !??g or "??g

si/es. 4haracters are often pressed into the s$uare, as in the example

illustrated.

3ushroom QHnch8 Riterally meaning (tight tea,( the tea is shaped

much like a "@?g to 1??g t7ocha, but with a stem rather than a convex

hollow. &his makes them $uite similar in form to a mushroom. Pu%er tea of this

shape is generally produced for &ibetan consumption.

3elon, or gold melon Q-ngu Ets shape is similar to tuOch8, but

larger in si/e, with a much thicker body decorated with pumpkin'like stripes.

&his shape was created for the famous (&ribute tea() made expressly for

the Ling :ynasty emperors from the best tea leaves of


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Sreen>raw pu%er, pressed maocha that has not undergone additional

processing* high $uality green pu%er is highly sought by collectors.

5ipened>cooked pu%er, pressed maocha that has undergone fermentation in

the ripening process for up to a year. Kadly fermented maocha will create a

muddy tea with fishy and sour flavors indicative of inferior aged pu%er.Aged raw pu%er, a tea that has undergone a slow secondary oxidation and a

certain degree of microbial fermentation. Although all types of pu%er can be

aged, the pressed raw pu%er is typically the most highly regarded, since aged

maocha and ripened pu%er both lack a clean and assertive taste.

5egionsedit]


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Qingmai )+

N8nnu9 ) + a varietal of tea grows here called /^Tun ), literally (purple

lady( whose buds and bud leaves have a purple hue.

Kada )+


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of tea as pu%er to tea produced within specific regions of the


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the printed wrappers and identifiers that come with the pu%er cake makes

identification of the tea a difficult task. Pu%er Tournals and similar annual

guides such as &he Profound World of 4hi &se, Pu'erh


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Animal Kyproducts Emport 6xport company )4NNP,


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#ccasionally, a three digit code is attached to the recipe number by

hyphenation. &he first digit of this code represents the year the cake was

produced, and the other two numbers indicate the production number within

that year. For instance, the seven digit se$uence Y@1'?", would indicate thesecond production in "?? of factory recipe Y@1. 2ome productions of cakes

are valued over others because production numbers can indicate if a tea was

produced earlier or later in a season>year. &his information allows one to be

able to single out tea cakes produced using a better batch of m8och8.

&ea packagingedit]

Pu%er tea is specially packaged for trade, identification, and storage. &hese

attributes are used by tea drinkers and collectors to determine the

authenticity of the pu%er tea.

Endividual cakesedit]

&ypical contents of a wrapped K^ngch8

Pu%er tea cakes, or K^ngch8, are almost always sold with"Y] a+

Wrapper+ 3ade usually from thin cotton cloth or cotton paper and shows the

tea company>factory, the year of production, the region>mountain of harvest,

the plant type, and the recipe number. &he wrapper can also contain decals,

logos and artwork. #ccasionally, more than one wrapper will be used to wrap

a pu%er cake.Ni fGi ) or + A small ticket originally stuck on the tea cake but now

usually embedded into the cake during pressing. Et is usually used as proof, or

a possible sign, to the authenticity of the tea. 2ome higher end pu%er cakes

have more than one ni fGi embedded in the cake. &he ticket usually indicates

the tea factory and brand.

Ni pio ) + A larger description ticket or flyer packaged loose under the

wrapper. Koth aid in assuring the identity of the cake. Et usually indicates

factory and brand. As well, many ni pio contain a summary of the tea

factories% history and any additional laudatory statements concerning the tea,

from its taste and rarity, to its ability to cure diseases and effect weight loss.

K^ng+ &he tea cake itself. &ea cakes or other compressed pu%er can be made up

of two or more grades of tea, typically with higher grade leaves on the outside

of the cake and lower grades or broken leaves in the center. &his is done to

improve the appearance of the tea cake and improve its sale. Predicting the

grade of tea used on the inside takes some effort and experience in selection.

Uowever, the area in and around the dimple of the tea cake can sometimes

reveal the $uality of the inner leaves.

A tng of recipe CC=" tea cakes wrapped in bamboo shoot husks


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5ecently, ni fGi have become more important in identifying and preventing

counterfeits. 3enghai &ea Factory in particular has begun microprinting and

embossing their tickets in an effort to curb the growth of counterfeit teas

found in the marketplace in the late !BB?s and early "???s. 2ome ni fGi also

include vintage year and are production'specific to help identify the cake andprevent counterfeiting through a surfeit of different brand labels.

Wholesaleedit]

When bought in large $uantities, pu%er tea is generally sold in stacks, referred

to as a tng ) , which are wrapped in bamboo shoot husks, bamboo stem

husks, or coarse paper. 2ome tongs of vintage pu%er will contain a tng pio

), or tong ticket, but it is less common to find them in productions past

the year "???.!"] &he number of b^ngch8 in a tng varies depending on the

weight of individual b^ngch8. For instance one tng can contain+

2even 1@CJ@??g b^ngch8,

Five "@?g mini'b^ngch8

&en !??g mini'b^ngch8

&welve tng are referred to as being one Tin ) , although some

producers>factories vary how many tng e$ual one Tin. A Tin of tea, which is

bound together in a loose bamboo basket, will usually have a large batch

ticket ) * pinyin+ dpio affixed to its side that will indicate information

such as the batch number of the tea in a season, the production $uantities,

tea type, and the factory where it was produced.!"]Aging and storageedit]

Pu%er teas of all varieties, shapes, and cultivation can be aged to improve their

flavor, but the tea%s physical properties will affect the speed of aging as well

as its $uality. &hese properties include+

Reaf $uality+ &he most important factor, arguably, is leaf $uality. 3aocha that

has been improperly processed will not age to the level of finesse as properly

processed maocha. &he grade and cultivation of the leaf also greatly affect its

$uality, and thus its aging.

4ompression+ &he tighter a tea is compressed, the slower it will age. En this

respect, looser hand' and stone'pressed pu%ers will age more $uickly than

denser hydraulic'pressed pu%er.

2hape and si/e + &he more surface area, the faster the tea will age. Kingcha

and /huancha thus age more $uickly than golden melon, tuocha, or Tincha.

Rarger bingcha age slower than smaller bingcha, and so forth.

Qust as important and the tea%s properties, environmental factors for the tea%s

storage also affect how $uickly and successfully a tea ages. &hey include+

Air flow+ 5egulates the oxygen content surrounding the tea and removes odorsfrom the aging tea. :ank, stagnant air will lead to dank, stale smelling aged


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tea. Wrapping a tea in plastic will eventually arrest the aging process.

#dors+ &ea stored in the presence of strong odors will ac$uire them,

sometimes for the duration of their (lifetime.( Airing out pu%er teas can reduce

these odors, though often not completely.

Uumidity + &he higher the humidity, the faster the tea will age. Ri$uid wateraccumulating on tea may accelerate the aging process but can also cause the

growth of mold or make the flavor of the tea less desirable. ?JY@ humidity

is recommended."B] Et is argued whether tea $uality is adversely affected if it

is subTected to highly fluctuating humidity levels.

2unlight+ &ea that is exposed to sunlight dries out prematurely, and often

becomes bitter.

&emperature+ &eas should not be subTected to high heat since undesirable

flavors will develop. Uowever at low temperatures, the aging of pu%er tea will

slow down drastically. Et is argued whether tea $uality is adversely affected if

it is subTected to highly fluctuating temperature.

When preserved as part of a tong, the material of the tong wrapper, whether

it is made of bamboo shoot husks, bamboo leaves, or thick paper, can also

affect the $uality of the aging process. &he packaging methods change the

environmental factors and may even contribute to the taste of the tea itself.

Further to what has been mentioned it should be stressed that a good well'

aged pu%er tea is not evaluated by its age alone. Rike all things in life, there

will come a time when a pu%er teacake reaches its peak before stumbling intoa decline. :ue to the many recipes and different processing method used in

the production of different batches of pu%er, the optimal age for each age will

vary. 2ome may take !? years while others "? or 1? years. Et is important to

check the status of ageing for your teacakes to know when they peaked so

that proper care can be given to halt the ageing process.

5aw Pu%eredit]

#ver time, raw pu%er ac$uires an earthy flavor due to slow oxidation and

other, possibly microbial processes. Uowever, this oxidation is not analogous

to the oxidation that results in green, oolong, or black tea, because the

process is not cataly/ed by the plant%s own en/ymes but rather by fungal,

bacterial, or autooxidation influences. Pu%er flavors can change dramatically

over the course of the aging process, resulting in a brew tasting strongly

earthy but clean and smooth, reminiscent of the smell of rich garden soil or an

autumn leaf pile, sometimes with roasted or sweet undertones. Kecause of its

ability to age without losing ($uality(, well aged good pu%er gains value over

time in the same way that aged roasted oolong does.1?]

5aw pu%er can undergo (wet storage( )sh-cng, and (dry storage()gncng , with teas that have undergone the latter ageing more slowly,


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but thought to show more complexity. :ry storage involves keeping the tea in

(comfortable( temperature and humidity, thus allowing the tea to age slowly.

Wet or (humid( storage refers to the storage of pu%er tea in humid

environments, such as those found naturally in Uong Dong, Suang/hou and, to

a lesser extent, &aiwan.

&he practice of (Pen 2hui( involves spraying the tea with water and

allowing it dry off in a humid environment. &his process speeds up oxidation

and microbial conversion, which only loosely mimics the $uality of natural dry

storage aged pu%er. (Pen 2hui( pu%er not only does not ac$uire the nuances

of slow aging, it can also be ha/ardous to drink because of mold, yeast, and

bacteria culturescitation needed].

Pu%er properly stored in different environments can develop different tastes at

different rates due to environmental differences in ambient humidity,

temperature, and odors.!"] For instance, similar batches of pu%er stored in

the different environments of &aiwan and Uong Dong are known to age very

differently. Kecause the process of aging pu%er is lengthy, and teas may

change owners several times, a batch of pu%er may undergo different aging

conditions, even swapping wet and dry storage conditions, which can

drastically alter its flavor. 5aw pu%er can be ruined by storage at very high

temperatures, or exposure to direct contact with sunlight, heavy air flow,

li$uid water, or unpleasant smells.

Although low to moderate air flow is important for producing a good'$uality

aged raw pu%er, it is generally agreed by most collectors and connoisseurs

that raw pu%er tea cakes older than 1? years should not be further exposed to

(open( air since it would result in the loss of flavors or degradation in

mouthfeel. &he tea should instead be preserved by wrapping or hermetically

sealing it in plastic wrapping or ideally glass.

5ipe Pu%eredit]

2ince the ripening process was developed to imitate aged raw pu%er, many

arguments surround the idea of whether aging ripened pu%er is desirable.

3ostly, the issue rests on whether aging ripened pu%er will, better or worse,

alter the flavor of the tea.

Et is often recommended to age ripened pu%er to (air out( the unpleasant

musty flavors and odors formed due to maocha fermentation. Uowever, some

collectors argue that keeping ripened pu%er longer than !? to !@ years makes

little sense, stating that the tea will not develop further and possibly lose its

desirable flavors. #thers note that their experience has taught them that

ripened pu%er indeed does take on nuances through aging,"Y] and point toside'by'side taste comparisons of ripened pu%er of different ages. Aging the


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tea increases its value, but may be unprofitable.

Preparationedit]

Preparation of pu%er involves first separating a well'si/ed portion of the

compressed tea for brewing. &his can be done by flaking off pieces of the cakeor by steaming the entire cake until it is soft from heat and hydration."Y] A

pu%er knife, which is similar to an oyster knife or a rigid letter opener, is used

to pry large hori/ontal flakes of tea off the cake to leaf breakage. 2maller

cakes such as tuocha or mushroom pu%er are often steamed until they can be

rubbed apart and then dried. En both cases, a vertical sampling of the cake

should be obtained since the $uality of the leaves in a cake usually varies

between the surface and the center.

Pu%er is generally expected to be served Songfu style, generally in


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Good pressed pu'er often have a matte sheen on the surface of the cake, though this is not

necessarily a sole indicator of quality

Liquor: The tea liquor of both raw and ripe pu'er should never appear cloudy. ell!aged raw pu'er

and well!crafted ripe pu'er tea may produce a dark reddish liquor, reminiscent of a dried "u"ube,

but in either case the liquor should not be opaque, #muddy,# or black in color. The flavors of pu'erliquors should persist and be revealed throughout separate or subsequent infusions, and never

abruptly disappear, since this could be the sign of added flavorants.

$oung raw %uerh:The ideal liquors should be aromatic with a light but distinct odors of camphor,

rich herbal notes like &hinese medicine, fragrance floral notes, hints of dried fruit aromas such as

preserved plums, and should ehibit only some grassy notes to the likes of fresh sencha. $oung

raw pu'er may sometimes be quite bitter and astringent, but should also ehibit a pleasant

mouthfeel and #sweet# aftertaste, referred to as g(n )* and h+ig(n)*.

ged raw %uerh: ged pu'er should never smell moldy, musty, or strongly fungal, though some

pu'er drinkers consider these smells to be unoffensive or even en"oyable. The smell of aged pu'er

may vary, with an #aged# but not #stuffy# odor. The taste of aged raw pu'er or ripe pu'er should be

smooth, with slight hints of bitterness, and lack a biting astringency or any off!sour tastes. The

element of taste is an important indicator of aged pu'er quality, the teture should be rich and thick

and should have very distinct g(n ) * and h+ig(n) * on the tongue and cheeks, which together

induces salivation and leaves a #feeling# in the back of the throat.

-pent tea: hole leaves and leaf bud systems should be easily seen and picked out of the wet

spent tea, with a limited amount of broken fragments. Twigs, and the fruits of the tea plant should

not be found in the spent tea leaves, however animal )and human* hair, strings, rice grains and

chaff may occasionally be included in the teacitation needed/. The leaves should not crumble

when rubbed, and with ripened pu'er, it should not resemble compost. ged raw pu'er should haveleaves that unfurl when brewed while leaves of most ripened pu'er will generally remain closed.

%racticesedit/

0n &antonese culture, pu'er is known as po!lay )or bo!lay* tea. mong the &antonese long settled

in &alifornia, it is called bo!nay or po!nay tea. 0t is often drunk during dim sum meals, as it is

believed to help with digestion. 0t is not uncommon to add dried osmanthus flowers, pomelo rinds,

or chrysanthemum flowers into brewing pu'er tea in order to add a light, fresh fragrance to the tea

liquor. %u'er with chrysanthemum is the most common pairing, and referred as guk pou or guk bou

)1 pinyin: "+ p2*.

-ometimes wolfberries are brewed with the tea, plumping in the process.

3ealthedit/

-ee also: %otential effects of tea on health

-cientific studies report that consumption of pu'er tea leaves significantly suppressed the

epression of fatty acid synthase )4-* in the livers of rats1 gains in body weight, levels of

triacylglycerol, and total cholesterol were also suppressed.56/57/ The compositions of chemical

components found to have been responsible for these effects )catechins, caffeine, and theanine*

varied dramatically between pu!erh, black, oolong, and green teas.56/


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-pecific mechanisms through which chemicals in pu'er tea inhibit the biosynthesis of cholesterol

in the laboratory have been suggested.55/

%u'er tea has also been found to have antimutagenic and antimicrobial properties in vitro.58/ )0n

vitro studies do not necessarily correlate to medicinal effects. n article in 9icrobiologist, Themagaine of the -ociety for pplied 9icrobiology, in 9arch 7;; ?o 6, p5@, found that tea

had many in vitro antimicrobial properties against many organisms1 for eample Anglish Breakfast

tea at the concentration used for drinking had significant antimicrobial effect on the lethal anthra

bacillus )Bacillus anthracis* and many others, but this did not make it a useful treatment for

anthra.*

%u'er tea is widely believed in &hinese cultures to counteract the unpleasant effects of heavy

alcohol consumptioncitation needed/. 0n traditional &hinese medicine it is believed to invigorate

the spleen and inhibit #dampness.# 0n the stomach, it is believed to reduce heat and #descends qi#.

citation needed/

%u'er tea is widely sold, by itself or in blends, with unsubstantiated claims that it promotes loss of

body weight in humans.

-ome pu'er brick tea has been found to contain very high levels of fluorine, because it is generally

made from lesser quality older tea leaves and stems, which accumulate fluorine.5@/ 0ts

consumption has led to fluorosis )a form of fluoride poisoning that affects the bones and teeth* in

areas of high brick tea consumption, such as Tibet.5C/5D/

gingedit/

%u'er tea can generally improve in taste over time )due to natural secondary oidation and

fermentation*. Teas that can be aged finely are typically:

9ade from high quality material

%rocessed skillfully

-tored properly over the years

The common misconception is that all types of pu'er tea will improve in tasteEand therefore gain

in valueEas they get older. There are many requisite variables for a pu'er tea to age beautifully.

4urther, the ripe )shou* pu'er will not evolve as dramatically as the raw )sheng* type will over time

due to secondary oidation and fermentation.

s with wine, only finely made and properly stored teas will improve and increase in value.

-imilarly, only a small percentage of teas will improve over a long period of time.

4rom 7;;< %u'er prices dropped dramatically. 0nvestment!grade %u'er did not drop as much as the

commoner varieties. 9any producers made large losses, and some decided to leave the industry

altogether.5


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Fombucha &hinese: ch"Hn ) *, Forean: chabeoseot ) *, Iussian: chaynyy grib )JKMN

OPQR*, is a lightly effervescent fermented drink of sweetened black tea that is used as a functional

food. 0t is produced by fermenting the tea using a symbiotic colony of bacteria and yeast, or

#-&SB$#. lthough kombucha is claimed to have several beneficial effects on health, these

claims are not supported by scientific evidence. rinking kombucha has been linked to serious

side effects and deaths, and improper preparation can lead to contamination.6/

&ontents hide/

6 Atymology

7 3istory

5 &hemical and biological properties

8 3ealth claims

@ Brewing kombucha

@.6 -afety and contamination

C -ee alsoD Ieferences


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< 4urther reading

> Aternal links

Atymologyedit/

The Anglish word kombucha, which was first recorded in 6>>@, has an uncertain etymology.7/

The merican 3eritage ictionary suggests: #%robably from Uapanese kombucha, tea made from

kombu )the Uapanese word for kelp perhaps being used by Anglish speakers to designate

fermented tea due to confusion or because the thick gelatinous film produced by the kombucha

culture was thought to resemble seaweed*.#5/

Fonbucha ) V, #kelp tea#* is a brownish beverage made from dried and powdered kombu

#edible kelp from the Laminariaceae family#.8/ The proper Uapanese name for what mericans

know as kombucha is kWcha kinoko )literally, 'red tea mushroom'*, compounding kWcha

#red tea# and kinoko #mushroom1 toadstool#. The &hinese names for kombucha are hXngch"Yn

)'red tea fungus'*, chmZi"Yn )'tea mold'*, or hXngchgH )'red tea

mushroom'*, with "Hn 'fungus, bacterium or germ' )or "Yn 'mushroom'*, mZi"Hn 'mold or

fungus', and gH 'mushroom'. )#Ied tea#, , in &hinese languages corresponds to Anglish #black

tea#.*

6>C@ mycological study called kombucha #tea fungus# and listed other names: #teeschwamm,

Uapanese or 0ndonesian tea fungus, kombucha, wunderpil, hongo, ca"ni", fungus "aponicus, and

teekwass.#@/ -ome further spellings and synonyms include combucha and tschambucco, andhaipao, kargasok tea, kwassan, 9anchurian fungus or mushroom, spumonto, as well as the

misnomers champagne of life, and chai from the sea.C/clarification needed/

3istoryedit/

Fombucha originated in ?ortheast &hina or 9anchuria and later spread to Iussia and from there

to the rest of the world.D/ 0n Iussian, the kombucha culture is called chainy" grib JKMN OPQR

)lit. #tea fungus[mushroom#*, and the fermented drink is called chainy" grib, grib )#fungus1

mushroom#*, or chainy" kvas JKMN \]K^ )#tea kvass#*. Fombucha was highly popular and seen

as a health food in &hina in the 6>@;s and 6>C;s. 9any families would grow kombucha at home.

0t was brought to Iussia sometime before 6>6; and spread from there to Germany and Aurope./

&hemical and biological propertiesedit/

$east and bacteria in kombucha at 8;;`


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The kombucha culture is a symbiotic culture of bacteria and yeast )-&SB$*, comprising

cetobacter )a genus of acetic acid bacteria* and one or more yeasts. These form a oogleal mat.

0n &hinese, this microbial culture is called haomo in &antonese, or "iaomu in 9andarin, )&hinese:

1 literally #yeast mother#*. 0t is also known as 9anchurian 9ushroom.

kombucha culture may contain one or more of the yeasts -accharomyces cerevisiae,

Brettanomyces bruellensis, &andida stellata, -chiosaccharomyces pombe, Torulaspora

delbrueckii, and ygosaccharomyces bailii. lcohol production by the yeast)s* contributes to the

production of acetic acid by the bacteria.

lthough the bacterial component of a kombucha culture comprises several species, it almost

always includes Gluconacetobacter ylinus )formerly cetobacter ylinum*, which ferments the

alcohols produced by the yeast)s* into acetic acid. This increases the acidity while limiting the

alcoholic content of kombucha. G. ylinum is responsible for most or all of the physical structure

of a kombucha mother, and has been shown to produce microbial cellulose.6;/ This is likely due

to artificial selection by brewers over time, selecting for firmer and more robust cultures.

The acidity and mild alcoholic element of kombucha resists contamination by most airborne

molds or bacterial spores. s a result, kombucha is relatively easy to maintain as a culture outside

of sterile conditions. The bacteria and yeasts in kombucha promote microbial growth.

The kombucha culture can also be used to make an artificial leather.66/

Fombucha flavoured with rose hips

Fombucha contains multiple species of yeast and bacteria along with the organic acids, active

enymes, amino acids, and polyphenols produced by these microbes. The precise quantities of a

sample can only be determined by laboratory analysis and vary depending on the fermentation

method, but kombucha may contain any of the following: cetic acid, Athanol, Gluconic acid,

Glucuronic acid, Glycerol, Lactic acid, snic acid and B!vitamins.67/65/68/

ccording to the merican lcohol and Tobacco Ta and Trade Bureau, many Fombucha

products contain more than ;.@ alcohol by volume, but some contain less.6@/

9any claims have focused on glucuronic acid,6C/ a compound used by the liver for

detoification. The idea that glucuronic acid is present in kombucha is based on the observation

that glucuronic acid con"ugates )glucuronic acid waste chemicals* are increased in the urine after

consumption. Aarly chemical analysis of kombucha brew suggested glucuronic acid was the key

component, and researcherscitation needed/ hypothesied that the etra glucuronic acid would

assist the liver by supplying more of the substance during detoification. These analyses were

done using gas chromatography to identify the chemical constituents, but this method relies on

having proper chemical standards 6D/ to match to the unknown chemicals.


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Ieports of adverse reactions may be related to unsanitary fermentation conditions, leaching of

compounds from the fermentation vessels, or #sickly# kombucha cultures that cannot acidify the

brew.6/ hile no randomied, case!controlled studies have been published in

relation to its effect on humans, there has been suspicion in isolated incidents of its effect on the

central nervous system, liver, metabolic acidosis, and toicity in general,7;/76/ though no

specific links have been established. cute conditions, such as lactic acidosis, caused by drinking

of kombucha, are more likely to occur in persons with pre!eisting medical conditions.76/ Sther

reports suggest care should be taken when taking medical drugs or hormone replacement therapy

while regularly drinking kombucha.77/ 0t may also cause allergic reactions.75/

-ome health claims may be due to the simple acidity of the drink, possibly influencing the

production of stomach acids or modifying the communities of microorganisms in thegastrointestinal tract.78/

Brewing kombuchaedit/

Fombucha is typically produced by placing a culture in a sweetened tea, as sugars are necessary

for fermentation. Black tea is a popular choice, but green tea, white tea and yerba mate may also

be used. 3erbal teas or those treated with oils may harm the kombucha culture over time.7@/

standard kombucha recipe calls for one cup of sugar per gallon of water or tea, though some

variation in the ratio is tolerated by the culture. Fombucha may be fermented with many different

sugar sources, including refined white sugar, evaporated cane "uice, brown sugar, glucose[fructose

syrups, molasses and honey )pasteuried only*. 3igh concentration of honey and its bacteriostatic

agents may potentially disturb the stability of the culture. Fombucha should never be fermented

with stevia, ylitol, lactose, or any artificial sweetener.7C/

The container is often covered with a closed!weave cloth to prevent contamination by dust, mold,

and other bacteria, while allowing gas transfer )#breathing#*. #baby# )new layer of the -&SB$*

is produced on the liquid[gas interface during each fermentation. The surface area is the most

favorable location for both aerobic bacteria on the top of the new #pancake# and anaerobic

bacteria on the bottom. The surface area also has ideal concentration of oygen for the yeast in thematri to propagate readily.


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fter a week or two of fermentation, the liquid is tapped. -ome liquid is retained for the

subsequent batch to keep the p3 low to prevent contamination. This process can be repeated

indefinitely. 0n each batch, the #mother# culture will produce a #baby#, which can be directly

handled, separated like two pancakes, and moved to another container. The yeast in the tappedliquid will continue to survive. secondary fermentation may be accomplished by removing the

liquid to a closed container )bottle* for about a week to produce more carbonation. &are should be

taken, as carbon dioide build up can cause bottles to eplode.

Left entirely alone to ferment with oygen, the kombucha settles into months of production time

)the #baby# thickening considerably*, creating an ever more acidic and vinegar!flavored cider. t

any point the kombucha can be tapped or have tea added. Liquid from the previous batch will

preserve some of the culture.

-afety and contaminationedit/

9old contamination on the culture surface.

s with other foods, there is a risk of contamination during preparation and storage. Fey

components of food safety when brewing kombucha include clean environment, proper

temperature, and low p3. 0f a culture becomes contaminated, it will most likely be identifiable as

common mold which is often green, blue, or black in color. This is visually distinct from the

brownish root filaments on the underside of the culture. 0f mold does grow on the surface of the

kombucha culture, or #mushroom#, both culture and tea are disposed of and the maker must start

again with a fresh kombucha culture.

There is a greater risk of mold growth when the kombucha mushroom is lifted out of the liquid by

its own gases, thus keeping it covered with liquid in the later stages, i.e. when the new kombucha

mushroom starts growing, can successfully prevent mold from growing.

The low rate of contamination by the home brewer might be eplained by protective mechanisms,

such as formation of organic acids and antibiotic substances. Thus, sub"ects with healthy

metabolisms are appropriate for cultivating kombucha tea cultures to drink the product tea.

3owever, those suffering from immunosuppression should preferably consume controlled

commercial kombucha beverages.7D/

0n every step of the preparation process, it is important that hands and utensils )or anything that

will to come into contact with the culture* be well cleaned to prevent contamination of the

kombucha. lso, kombucha becomes very acidic )approimately p3 5.; when finished*, so it can

leach unwanted and potentially toic materials from containers in which it is fermenting if they

are not food!grade.6


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9aintaining a correct p3 is an important factor in a home brew. cidic conditions are favorable

for the growth of the kombucha culture, and inhibit the growth of molds and bacteria. The p3 of

the kombucha batch should be between 7.@ and 8.C. p3 of less than 7.@ makes the drink too

acidic for normal human consumption, while a p3 greater than 8.C increases the risk of

contamination.7>/ se of fresh #starter tea# and[or distilled vinegar can be used to control p3.-ome brewers test the p3 at the beginning and the end of the brewing cycle to ensure the correct

p3 is achieved and the brewing cycle is complete.

dvantages

hat re 4ermented 4oodsV

4ermented foods are foods that have been through a process of lactofermentation in which natural

bacteria feed on the sugar and starch in the food creating lactic acid. This process preserves the

food, and creates beneficial enymes, b!vitamins, Smega!5 fatty acids, and various strains of

probiotics.

?atural fermentation of foods has also been shown to preserve nutrients in food and break the

food down to a more digestible form. This, along with the bevy of probiotics created during the

fermentation process, could eplain the link between consumption of fermented foods and

improved digestion.


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&ultures around the world have been eating fermented foods for years, from -auerkraut in

Germany to Fimichi in Forea and everywhere in between. -tudies have even shown the link

between probiotic rich foods and overall health )%4*. -adly, with the advances in technology and

food preparation, these time!honored traditional foods have been largely lost in our society.

here 3ave ll the 4ermented 4oods GoneV

The amount of probiotics and enymes available in the average diet has declined sharply over the

last few decades as pasteuried milk has replaced raw, pasteuried yogurt has replaced homemade,

vinegar based pickels and sauerkraut have replaced traditional lacto!fermented versionsthe list

goes on.

Aven the much dreaded grains were safer to eat in earlier times since their preparation included

soaking, sprouting and fermenting, which largely reduces the anti!nutrient content and makes

them less harmful )0 still didnt say good*.

0nstead of the nutrient rich foods full of enymes and probiotics that our grandparents probably

ate, the average diet today consists mainly of sugar laden, lab created dead foods.

hy Aat 4ermented 4oodsV

Besides the fact that they taste great and really grow on you, there are several great reasons to start

making and eating fermented foods:

%robiotics! Aating fermented foods and drinking fermented drinks like Fefir and Fombucha will

introduce beneficial bacteria into your digestive system and help the balance of bacteria in your

digestive system. %robiotics have also been shown to help slow or reverse some diseases, improvebowel health, aid digestion, and improve immunity

bsorb 4ood Better! 3aving the proper balance of gut bacteria and enough digestive enymes

helps you absorb more of the nutrients in the foods you eat. %air this with your healthy real food

diet, and you will absorb many more nutrients from the foods you eat. $ou wont need as many

supplements and vitamins, and youll be absorbing more of the live nutrients in your foods.

Budget 4riendly! 0ncorporating healthy foods into your diet can get epensive, but not so with

fermented foods. $ou can make your own whey at home for a couple of dollars, and using that and

sea salt, ferment many foods very inepensively. rinks like ater Fefir and Fombucha can be

made at home also and cost only pennies per serving. dding these things to your diet can also cut

down on the number of supplements you need, helping the budget further.

%reserves 4ood Aasily! 3omemade salsa only lasts a few days in the fridge! 4ermented homemade

salsa lasts months The same goes for sauerkraut, pickles, beets and other garden foods. Lacto!

fermentation allows you to store these foods for longer periods of time without losing the nutrients

like you would with traditional canning.

Bring on the Bacteria 3ow to 0ncorporate 4ermented 4oods 0nto $our iet

0ll be delving into this more in the net few weeks and providing some recipes, but adding

fermented foods to your diet can be an easy process )and can save you money on probiotics and

digestive enyme supplements*


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Sn a basic level, you can make foods like sauerkraut with "ust cabbage, water and salt on your

counter )that recipe can be ad"usted down to make 6 head of cabbage worth in a quart sie "ar*.

$ou can also incorporate fermented drinks like ater Fefir and Fombucha )cultures available

here* which are inepensive to make and can be carbonated like soda

-ome other great recipes from around the web:

Ieal 4ermented -our %ickles

Documents

Tea Fermentation