AFDC16(6181 )P3/Rev. TZS 76 4:2003     
ICS 67.120.10                                           
 
 
  
DRAFT TANZANIA STANDARD  
 
 
 
 
Malting barley – Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TANZANIA BUREAU OF STANDARDS  
 
 
 
 
 
 
 
 
 
 
 
 
  1 0  Foreword  
 
Barley is an important crop in Tanzania associated with production of beer and other malting 
purposes. Acceptabili ty of this product is determined by its overall malting performance,  
 
This Tanzania  Standard  therefore has been  prepared to provide guidance in evaluating  
good quality barley for malting purposes.  
 
In preparation of this Tanzania Standard, ass istance was drawn from the following publications:  
IS 6894, Malting  barley – Specification (First Revision)  published by the Bureau of Indian     
Standards.  
 
ISO/DIS 10520.2, Native starches - Determination of starch content  – Ewers polarimetric 
method   Published by the International Organization for Standardization.  
 
In   reporting   the   results  of a test or   analysis   made in accordance   with   this   Tanzania  
Standard, if the final value observed or calculated is to be rounded off, it shall be don e in 
accordance with TZS 4 (see clause 2).  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  2 1 Scope  
 
This Tanzania Standard prescribes requirements, methods of sampling and test for barley for 
preparing malt for brewing and other malting purposes.  
 
 
2  Normativ e References  
The following referenced documents are indispensable for the application of this document. For 
dated references, only the edition cited applies. For undated references, the latest edition of the 
referenced document (including any amendments) a pplies  
 
TZS 329/EAS 900,  Cereals – Sampling of grain:  
TZS 441, Cereals – Determination of moisture content.  
TZS 4, Rounding off numerical values.  
TZS 799, Agricultural food products – Determination of aflatoxins.  
TZS 331/EAS 901, Cereals – Milled products – Methods of test:  
TZS 331/EAS 901, Cereals grains – Methods of test . 
TZS 59:, Water –Distilled quality – Specification   
 
 
3 Terms and Definition  
 
For the  purpose of  this Tanzania Standard, the following terms and definitions shall apply:  
 
3.1   sound b arley   
Kernel of barley remaining after removal of foreign matter) and damaged kernel  
 
3.2   foreign matter  
 includes inorganic and organic matter. The inorganic matter includes  
sand, gravel, dirt, pebbles, stones, glass and metallic pieces, lumps of ea rth, clay and mud. 
Organic matter includes husk, chaff, straw, weed, seeds and extraneous matter including 
foreign grains.  
 
3.3   foreign grains  
other edible grains other than the grain under consideration.  
 
3.4   damaged kernels  
pest damaged, discoloure d, stained, rotten and diseased, immature and shrivelled grains and 
broken kernel.  
3.5   broken kernels  
 pieces of sound kernels that are less than three fourths of the size of  
full kernel.  
 
3.6   skinned kernels  
 kernels of barley from which one third  o r more of the hull has been  
loosened or removed over the germ.  
 
3.7   mealy barley  
kernels which when cut transversely, show a white endosperm having  
an opaque and mealy appearance.  
 
3.8   fine appearance  
characteristic appearance of grain not stained and withered.  
 
3.9   steely barley  
kernels which when cut transversely, show a vitreous endosperm.  
 
Define smutty, garlicy, weevily, ergot or bleached  
 
3.10  shrivelled or immature kernels kernels or pieces of kernel  which are not fully developed   3  
3.11 malting  
Is a biological process that turns barley into malt in three stage process including soaking or 
steeping the grain in water to bring the kernels to 45% moisture, germination under cool humid 
conditions and drying (kilning).  
 
3.12 malt  
is the germin ated cereal grain that has been dried in a process known as malting  
 
3.13 food grade packaging material  
material, made of substances which are safe and suitable for their intended use and which will 
not impart any toxic substance or undesirable odour or fl avour to the product  
 
4  Requirements  
 
4.1 General requirements  
 
Barley for malting purposes shall be free from living insects, moulds, dead insects, insect 
fragments and rodent contamination visible to eyes with the aid of a suitable   magnification (not 
exceeding x 10).  
 
When cut transversely, the kernels shall be mealy and not steely. The barley shall not be 
smutty, garlicy, weevily, ergot or bleached.  
 
4.2 Size 
 
The size of  barley kernels shall be such that not less than 30 percent by mass of kernels are 
retained on a sieve of aperture 2.8 mm, not less than 80 percent by mass are retained on a 
sieve of aperture 2.2 mm.  
 
The proportion of kernels passing through a 2.2 mm aperture sieve shall not exceed 2 per cent 
by mass.  
 
4.3   Barley for malting purposes  shall also conform to the requirements prescribed in  
table 1.  
 
 
Table 1 – Requirements for barley for malting purposes.  (Rearrange the table)  
 
 
S/N  
Characteristics   
Requirements   
Methods of Test  
  Brewing  Other purposes  
 
1 
 
 
 
2 
 
 
 
 
3 
 
 
 
 
4 
 
 
  
Moisture, percent 
by mass, max.  
 
 
Foreign matter, 
percent by mass, 
max 
 
 
Other edible 
grain, percent by 
mass, max.  
 
 
Damaged grains, 
percent by mass, 
max. 
  
12 
 
 
 
 
1.0 
 
 
 
0.5 
 
 
 
 
1.5 
 
 
  
12 
 
 
 
 
1.5 
 
 
 
1.0 
 
 
 
 
2.0 
 
 
  
TZS 331/EAS 901   
TZS 734:   
 
 
TZS 734  
 
 
 
TZS 734  
 
TZS 734   
 
TZS 734   
TZS 331/EAS901  
 
 
TZS 331/EAS 901  
  4 5 
 
 
 
 
6 
 
 
 
7 
 
 
 
8 
 
 
 
9 
 
 
 
 
10 
 
 
 
 
11 
 
 
 
12 
 
 
 
13 
 
 
14 Immature and 
shrivelled grains, 
percent by mass, 
max. 
 
Hectolitre mass, 
in kg/HL min.  
 
 
Specific gravity, 
max.  
 
 
Protein, percent 
by mass, max.  
 
 
Extract yield on 
dry basis, percent 
by mass, min. 
 
 
Starch content, 
percent by mass, 
min. 
 
Germination 
capacity, percent 
min. 
 
Germination 
energy, per cent 
min. 
 
 
 2.0 
 
 
 
 
65 
 
 
 
1.3 
 
 
 
9.0 
 
 
 
75 
 
 
 
 
50 
 
 
 
 
98 
 
 
 
92 
 
 
 
5.0 
 
 
10.0 2.5 
 
 
 
 
60 
 
 
 
1.2 
 
 
 
9.0 
 
 
 
80 
 
 
 
 
55 
 
 
 
 
95 
 
 
 
90 
 
 
 
5.0 
 
 
10.0 Annex D 
 
 
 
 
 
 
 
 
Annex A  
 
 
 
Annex A  
 
 
 
TZS 331/EAS901TZS 
331/EAS901  
  
 
 
5.0 Contaminants  
Aflatoxin B1 and Total aflatoxin (ppb), max. (ppb), max. Pesticides residues , Other contaminants, 
statement refer codex stan 193  
 
6.0 Sampling  
Sampling shall be done in accordance with TZS 330/EAS 900.  
 
7.0 Testing  
 
Tests shall be carried out in accordance with the appropriate methods specified in table 1.  
 
 
8.0 Packaging and marking  
 
8.1 Packaging  
 
Barley for malting  purposes sha ll be packed in moisture proof, sound and clean food grade 
packaging material.  
 
8.2 Marking and labelling  
Put statements which refer TZS 538  
Each container shall be marked or labelled with the following particulars:   5  
a) name and type of the barley;  
b) variety of the  barley (2 -rowed or six rowed);  
c) net mass;  
d) country of origin  
e) date of harvesting.  
f) name, address and physical location of the producer/packer/importer;  
g) storage instruction as “Store in a cool dry place away from any contaminants’’ and  
h) declaration that maltin g barley is not genetically modified,  
8.3 The containers shall also be marked with the TBS Standard Mark of Quality  
NOTE – the TBS Mark of quality may be used by the manufactures only under licence from 
TBS. Particular of conditions under which the licenc es are granted  may be obtained from TBS.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  6 ANNEX A  
 
Determination of germination capacity and germination energy  
 
A.1 Apparatus  
 
A.1.1 Soil and Sand Boxes  – Paraffined cardboard boxes of suitable sizes (preferabl y  
115 mm x 115 mm x 40 mm or 215 mm x 215 mm x 45 mm).  
  
A.1.2 Sprinkling Devices  – A suitable sprinkling device for moistening the substrata  
 
A.1.3 Thermometers . 
 
A.1.4 Germinator  – Any kind of germinator in which it is possible to maintain the necessary  
conditions of temperature and moisture.  
 
A.2  Germination substrata  
 
A.2.1 Sand  
 
A.2.2  Germination paper  
 
A.3  Procedure  
 
A.3.1  Take 100 grains of malting barley and place them on moistened germination paper or 
sand and keep in the germinator maintained at temperature between 15°C to 20°C. The first 
count of germinating shall be made after 3 days and final count after 6 days. Note the percent 
grains germinated at the time of each count.  
 
Carry out the tests in either duplicate or triplicate.  
 
A.3.2  The pe rcentage of barley grains  germinating on first count represent the germinative 
energy.  
 
A.3.3  The percentage of barley grains germinating at the final count represent the germination 
capacity of the sample under test.  
 
ANNEX B   
 
Determination of yield of  extract  
 
B.1 Apparatus  
 
B.1.1 Grinding mills – Miag – Seck type. For fine grinding use cone type, 300 rev/min and for 
coarse grinding roll type 150 rev/min.  
 
B.1.2 Mash beakers and counter weights , Made of either pure nickel stainless steel or brass 
and o f such dimensions as to assure tight connection between beakers and grinding mill. If 
counter weights are used for mash beakers, their tare should be checked frequently.  
 
B.1.3 Mashing apparatus  – The beakers, stirrers and solders used should be of the sam e 
metal. Each stirrer should be provided with a blade which during operation has clearance of 
about 2 mm from bottom and 5 mm from wall of the mash beaker. The blade is approximately  
8 mm wide and each side has 45 pitch, arranged as in a propeller, to for ce mash upward. 
Speed of the mash stirrer shall  be so to 100 rev/min, each stirrer of each beaker shall have the 
same speed. Stir water in the bath thoroughly by mechanical means to assure uniformity of 
temperature and have level of water above maximum ma sh level.  
 
B.1.4 Filter paper,  Whatman No. 1 or equivalent.  
 
B.1.5 Funnels,  Short -stem glass funnels having approximately a diameter of 20 cm. The stem 
shall extend 3 cm to 5 cm into the receiving flask.   7  
B.1.6 Flasks,  Erlenmeyer’s of 500 ml capacity.  
 
B.1.7 Pyknometers  
 
B.1.8 Water Bath, Automatically controlled  
 
B.2  Procedure  
 
B.2.1 Grinding  
 
Weigh approximately 55 g of sample at room temperature into a tared mash beaker and grind 
through mill set for standardized   fineness of grind. Collect finely grou nd barley in same mash 
beaker. Mix and without delay place mash beaker with contents on balance and adjust mass of 
the barley to 50.00 g ± 0.05 g by removing excess.  
 
B.2.2 Mashing procedure  
 
Mash in ground barley with 200 ml water at 46°C and mix well wit h glass rod to prevent 
formation of lumps. Carefully rinse glass rod and wall of beaker with small quantity of water. 
Promptly place mash beaker in mashing apparatus containing water previously heated to 46°C 
and set the stirrer in motion. Place thermomete r in the mash beaker. Keep temperature at 45°C 
exactly for 30 minutes from the time the beaker was placed in the mashing apparatus. Raise 
mash temperature at the rate of 1°C per minute till it reaches 70°C to 71°C and mash for 60 
minutes at 70°C. Care shou ld be taken that temperature deviations during mashing procedure 
do not exceed 0.5°C.  
 
B.2.3 Cooling and filtration  
 
After 60 minutes, cool mash promptly (within 10 to 15 minutes) to  the prevailing room 
temperature. Stop stirring. Remove thermometer after  adhering mash particles are rinsed into 
the beaker with water. Remove the beaker with its stirrer from the mashing apparatus. Rinse 
mash particles adhering to the stirrer into the beaker with water. Dry outside of the beaker 
taking care to remove the mois ture adhering to the rim. Without delay adjust the mass of 
contents of mash beaker to 450.00 g ± 0.5 g by adding water.  
 
Stir the mash thoroughly with glass rod once when removing the beaker from balance pan and 
again immediately before pouring mash into f ilter (stirring shall be not less than 5 minutes and 
not more than 15 minutes part). While stirring cooled mash, take care to prevent splashing or 
spilling. Mix drops adhering to beaker wall into mash by rotary stirring with glass rod.  
 
Pour entire content s of beaker into funnel provided with specified filter paper. Cover funnel with 
approximately 20 cm diameter watch -glass during entire filtration. In case of slow running works, 
stop filtration after 2 hours. In case of coarse ground malt mash collect exac tly 200 ml ± 2 ml 
wort. When filtration is complete mix wort in receiving flask thoroughly  by rotary motion.  Speed 
of filtration is normal if filtration is complete within one hour after returning the filtrate to filter 
bed; slow if filtration takes longe r. 
 
B.2.4 Specific gravity  
 
Rinse empty pyknometer twice with about 10 ml wort. Fill with wort, place in water bath 
maintained at 20°C. Weigh filled pyknometer within 3 hours of completed filtration. The 
difference between this mass and that of empty pykno meter represents wort capacity of 
pyknometer at 20°C. Calculate specific gravity of wort to 5 decimal places rounding off to 
0.00005 to 0.00010 by dividing mass of wort by mass of water.  
 
B.3   Calculation  
 
B.3.1 Determine extract yield of wort by referenc e to specific gravity values given in table 2.  
 
B.3.2  Calculate yield of extract of barley (on dry basis) as given below:  
  8 a) Extract as – is basis P (800 + M)/(100 -P) 
 
where  
  P = g extract in 100 g wort (as calculated from table 2).  
  M = percentage moistur e in the barley  
 
 
 
 
b) Extract (on dry basis) = ( E x 100)/(100 -M) 
 
where  
  E = Extract as is basis and  
  M = percent moisture in barley.  
 
 
ANNEX D  
 
Determination of starch content (ewers polarimetric methods) refer to TZS962.  
 
 
 
 