KENYA STANDARD                    DKS 65: 2016 
ICS 67.100.10  
 
 
 
  
 
  
 
  
 
 
Black tea — Specification  
 
 
      
 
              
© KEBS 2016         Fourth Edition 2016 DKS 65:2016 
 
                             KEBS 2016 — All rights reserved iiTECHNICAL COMMITTEE REPRESENTATION 
 
The following organizations were r epresented on the Technical Committee. 
 
Egerton University  Agriculture and Food Authority- Tea Directorate 
Ministry of Health — Public Health Department 
Government Chemist’s Department 
Melvin Mash International Ltd 
Unilever Tea Kenya Ltd Kenya Plant Health inspectorate Service 
Finlays Tea 
Tea Research Foundation of Kenya Ministry of industry, Trade and cooperatives 
Kenya Agricultural and Livestock organization 
Ministry of Agriculture Kenya Tea Development Agency Ltd 
Institute of Packaging of Kenya 
Consumer Information Network Kenya Bureau of Standards- Secretariat 
 
  
   
  
 
  
 
 
 
  
 
REVISION OF KENYA STANDARDS  
 
In order to keep abreast with the progress in the industry, Kenya Standards shall be regularly reviewed. 
Suggestions for improvements to publ ished standards, addressed to the Managing Director, Kenya Bureau of 
Standards, are welcome. 
 
   
© Kenya Bureau of Standards, 2016 
 Copyright. Users are reminded that by virtue of Section 25 of the Copyright Act, Cap. 12 of 2001  of the Laws of Kenya, copyrig ht subsists in 
all Kenya Standards and except as provi ded under Section 26 of this Act, no Kenya Standard produced by Kenya Bureau of Standard s may 
be reproduced, stored in a retrieval system in any form or trans mitted by any means without prior permission in writing from th e Managing 
Director. KENYA STANDARD                            DKS 65:2016  
ICS 67.100.10  
 
KEBS 2016 — All rights reserved    iii 
 
 
 
  
 
 
     
Black tea — Specification  
 
  
 
  
 
  
 
 
 
  
 
  
 
  
 
 
 
 
 
 
 
 
KENYA BUREAU OF ST ANDARDS (KEBS) 
 
Head Office:  P.O. Box 54974, Nairobi-00200, Tel.: (+254 020) 605490, 602350, Fax: (+254 020) 604031 
E-Mail: info@kebs.org,  Web:http://www.kebs.org  
 
Coast Region    Lake Region         Rift Valley Region  
P.O. Box 99376, Mombasa-80100  P.O. Box 2949, Ki sumu-40100       P. O. Box 2138, Nakuru-20100 
Tel.: (+254 041) 229563, 230939/40               Tel.: (+254 057) 23549, 22396       Tel.: (+254 051) 210553, 210555 
Fax: (+254 041) 229448   Fax: (+254 057) 21814              
 DKS 65:2016 
 
                             KEBS 2016 — All rights reserved iv Foreword 
This Kenya Standard has been prepared by the Tea Tech nical Committee under the guidance of the Standards 
Projects Committee and it is in accordance with t he procedures of the Kenya Bureau of Standards. 
 
The need to revise this standard has arisen from the increased need to accommodate technological innovations 
and the desire to position the Kenya tea as high quality offering in the tea world market.  Thus, there is a 
general need to address both economic and nutritional concerns. In the said dispensation, the standard 
promotes fair trade, safeguards the interests of the stakeholders and guarantees enhanced safety of the 
consumers. 
During the preparation of this standard, re ference was made to the following documents: 
      
ISO 1839: Sampling of tea. 
ISO 1572: Preparation of ground tea sample. ISO 3720: Black tea — Definitions and basic requirements. ISO 11286; 2004: Tea classification by particle size. 
ISO 16050: Determination of aflatoxin in foods. 
 
 
Acknowledgement is hereby made for the assistance derived from these sources 
 
 
 
  
                             KEBS 2016 — All rights reserved 2 
Black tea — Specification 
 
1 Scope 
 
This Kenya Standard specifies requirem ents and methods sampling and test of black tea of the species Camellia 
sinensis (Linneaus) O. Kuntze. This standard does not  apply to flavoured teas and decaffeinated black teas. 
 
2 Normative references 
 The following publications contain provisions which, through reference in this text, constitute provisions of this 
standard. At the time of publication, the edition indicat ed was valid. For undated references, the latest edition of the 
normative document referred to applies.  
 
AOAC 942.17, Arsenic in foods Molybdenum blue method AOAC 999.10, Lead, Cadmium, Copper, Iron, and Zinc in fo ods, Atomic Absorption Spectrophotometry after dry 
ashing 
KS EAS 39, Code of practice for food hygiene in the food and drink m anufacturing industry 
KS ISO 1573; Tea – Determination of loss in mass at 103 °C 
KS ISO 1839, Sampling of tea KS ISO 3103; Tea – Preparation of liquor for use in sensory tests   
KS ISO 18593; Microbiology of food and animal feeding stuffs  – Horizontal methods for sampling techniques from 
surfaces using contact plates and swabs   
KS ISO 4833-1; Microbiology of food and animal feeding st uffs - Horizontal method for the enumeration of 
microorganisms - Colony-count te chnique at 30 degrees C   
KS ISO 21527; Microbiology of food and animal feeding stuffs - Horizontal method for the enumeration of yeasts and 
moulds - Part 2: Colony count technique in product s with water activity less than or equal to 0,95   
KS ISO 16649-1; Microbiology of food and animal feeding st uffs – Horizontal method for the enumeration of 
betaglucuronidase-positive Escherichia coli – Part 1: Colony 
count technique at 44 degrees C using membranes a nd 5-bromo-4-chloro-3-indolyl beta-D-glucuronide   
KS ISO 16649-2; Microbiology of food and animal feeding stuffs - Horizontal method for the enumeration of 
betaglucuronidase-positive Escherichia coli - Part 2: Co lony count technique at 44 degrees C using 5-bromo-
4chloro-3-indolyl beta-D-glucuronide 
KS ISO 6579; Microbiology of food and animal feeding stuffs - Horizontal method for the detection of Salmonella spp   
KS EAS 38, Labelling of pre-packaged foods KS CODEX STAN 193, Codex general standard fo r contaminants and toxins in foods  
KS ISO 8968-1, Microbiology of food and animal feeding stuffs -- Horizontal method for the enumeration of 
coagulase-positive staphylococci (Staphylococcus aureus and other species) -- Part 1: Technique using Baird 
Parker agar medium 
KS ISO 15598; Tea- Determination of crude fibre
 
KS ISO 5498; Agricultural food products- Determinat ion of crude fibre content- General Method 
KS ISO 14502-2 (Tea – Methods for determination of substances  characteristic of green and black tea – Part 2: 
Determination of catechins in green tea – Method using high performance liquid chromatography) 
 
   
4        Requirements  DKS 65:  
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4.1      General requirements  
 
For purposes of this standard, the following definitions shall apply: 
 
3.1 black tea  
 
tea derived solely and exclusively produced by acceptable pr ocesses (notably withering, leaf maceration, aeration 
and drying) from the tender shoots of varieties of the spec ies Camellia sinensis (Linnaeus) O. Kuntze, known to be 
suitable for making tea for consumption as a beverage  
3.2 Extraneous matter 
 
Any material of tea origin such as twigs, barkand stems 
 
3.3 Foreign matter 
 
Any material which is not tea leaf, fl avour used or fragments of tea plant e. g. sand, stones, me tallic chips and any 
organic matter other than extraneous matter  
 
3.4 Contaminants 
 
Any physical or chemical or biological agent, foreign matte r, or any other substances not intentionally added to 
food which may compromise food safety or suitability 
 
3.5 Adulterant 
 
Any material intentionally added that changes the origi nal composition and compromises the quality and safety of 
black tea 
 
3.6 Filth 
 Any material such as, but not limited to dead insects, rodents and their derivatives
 
 
3.7 Taint  
 
Taste and odour foreign to tea 
 
 
4        Requirements  
 
4.1      General requirements  
 
Black tea shall comply with the following: 
 
4.1.1    Shall be of uniform colour. 
 
4.1.2    Shall be of typical texture and appearance. 
 
4.1.3    Shall have a typical flavour and taste. 
 
4.1.4    Shall be free from unpleasant or repulsive  odours but may have a typical aroma. 
 
4.1.5    Shall be free from contaminants  
                             KEBS 2016 — All rights reserved 4 
4.1.6        The tea shall have no taint and shall be reasonabl y free from extraneous matter .Liquor for assessment of 
taint shall be prepared by method specified in KS ISO 3103.  
The assessment shall be described in the test report using terms defined in KS ISO 6078. 
 DKS 65:  
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 4.2      Compositional quality requirements/limits  
 
4.2.1     The black tea shall comply with the re quirements/limits specified in Table 1. 
 
 
Table 1 ▬ Chemical requireme nt for black tea. 
 
SL No. Characteristic Requirement Methods of test 
(i) Moisture content %, m/m, max.  7.0 KS ISO 1573 
(ii) Water extract, percent (m/m) min. 32 KS ISO 9768 
(iii) Total ash, percent (m/m) 4-8 KS ISO 1575 
(iv) Water soluble ash, as percentage of total ash, 
min. 45 KS ISO 1576 
(v) Alkalinity of water-soluble ash (as KOH), percent 
(m/m) 1.0a- 3.0a KS ISO 1578 
(vi) Acid-insoluble ash, perc ent (m/m),max. 1.0 KS ISO 1577 
(vii) Crude fibre, perc ent (m/m), max. 16.5 KS ISO 5498 or KS ISO 
15598b 
(viii) Total polyphenols (m/m), min 9.0 KS ISO 14502-1 
(ix) Total Catechins content%, (m/m),min 7 KS ISO 14502-2 
a When the alkalinity of water-soluble ash is expresse d in terms of millimoles of KOH per 100 g of ground 
sample, the limits shall be: 17.8 min.; 53.6 max. 
 
b The specific method for the determination of crude fibr e in tea is specified in ISO 15598, however for the 
purpose of routine estimation, the general method specif ied in ISO 5498 is adequate. In cases of dispute, 
the method of determination should always be that  specified in ISO 15598. The requirement of 16.5 % 
mass fraction remains unchanged regardless of the method used. 
 
4.3       Preparation of tea liquor for sensory analysis 
            
Tea liquor for sensory analysis should be prepared in accordance to ISO 3103  
 
 
 
5.          Hygiene  
 
5.1 It is recommended that the products covered by the prov isions of this standard be prepared and handled in 
accordance with the appropriat e sections of KS EAS 39, and othe r relevant Keny a standards and 
regulations. The products should comply with any micr obiological criteria established in accordance with 
CAC/GL 21 
 5.2   The products shall comply with any microbiological criteria established in accordance with Table 2 below. 
 
 
     
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 Table 2- Microbiological  limits for black tea 
 
SL No  Type of micro-organism  Limits  Test method  
(i) Yeasts cfu/ g, max 102 ISO 21527-2 
(ii) Moulds cfu/ g, max 103  
(iii) Pathogenic Staphylococcus 
aureus cfu/ g, max Absent ISO 6888-1 
(iv) E. Coli , cfu/ g, max Absent ISO 7251 
(v) Salmonella spp, cfu/ 25 g, max  Absent ISO 6579 
 
 
8 Contaminants 
 
The product covered by this standard shall comply with the maximum levels of CODEX STAN 193 and the 
maximum residue limits for pesticides established by the Codex Alimentarius Commission (CAC). 
 
8.1       Heavy metals 
 
Heavy metal contaminants, if present, shall co mply with the limits specified in Table 2 . 
 
Table 2 — Heavy metal contaminant limits in black tea  
 
SL No.  Paramete r Limit Test method  
i) Arsenic ( As), ppm, max. 0.15 AOAC 999.10  
iv) Cadmium (Cd), ppm, max. 0.1 AOAC 942.17  
v) Mercury (Hg), ppm, max. 0.02 AOAC 999.10  
vi) Zinc (Zn), ppm, max. 50 AOAC 942.17  
vii) Copper (Cu), ppm, max. 150 AOAC 942.17  
 
viii) Iron filings,ppm max. 50 KS 2160 
 
   
8.2       Mycotoxin residues 
 
Total aflatoxin levels in black tea shall not exceed 10 ppb with B 1 not exceeding 5 ppb when tested according to KS 
ISO 16050 
 
 
8.5 Pesticide residues 
 
The products covered by the provisions of this standard shall conform to those maximum limits for pesticide residue 
limits established by the Codex A limentarius Commission for these products in codex Stan 193;  KENYA STANDARD                                 DKS 65:2016 
KEBS 2016 — All rights reserved     
 
 
 
7 Environment 
 
Black tea shall be produced, processed and handled under conditions complying with the stipulations of the 
Environmental Management and Co-ordination Act (EMCA), No.8 of 1999 of the Laws of Kenya, on 
environmental management and complying with cl eaner production technological practices. 
 
7 Packaging 
 
7.1 The tea shall be packed in suitable, clean and dry cont ainers, made of material, which does not change 
the tea quality (preserves tea quality) 
 
7.2      The fill of the package shall comply with the Weights and Measures Act, Cap. 513 of the Laws of 
Kenya. 
 
7.3 The disposal of used package and condemned black tea shall be carried out in compliance with the 
Environmental Management and Coordination Act (EMCA) , Waste Regulations, 2006 of the Laws of Kenya 
on disposal of solid and liquid wastes. 
 
11 Labelling 
 
8.1      In addition to the provisions of the General Standard for the Labelling of Prepackaged Foods; KS EAS 
38, the following specific provisions apply:  
 i) product name as “Black Tea’’; 
ii) name, address and physical location of t he manufacturer/ packer/ importer/ exporter; 
iii) date of manufacture; 
iv) expiry date; 
v) method of manufacturing; 
vi) the declaration “Food for Human Consumption”; 
vii) storage instructions as ‘’Store in a Cool Dry Place, Away from Contaminants and direct sunlight’’; 
viii) lot/batch/code number; 
ix) net weight in g or kg; 
x) instructions on disposal of used package; and 
xi) country of origin  
8.2 A declaration of any inaccurate information in ma rking/labelling is prohibited and shall be punishable by 
law under the Standards Act, Cap.  496, of the Laws of Kenya. 
 
 11 Sampling  
Sampling of black tea for analysis shall be carried out in compliance with KS ISO1839.