DRAFT UGANDA STANDARD  
  DUS nnnn  
First  Edition  
2021 -08-21 
 
 
 Reference number  
DUS nnnn: 2021  
© UNBS 2021   
  
Sorghum m alt — Specification  
 DUS nn nn: 2021   
ii © UNBS 2021  – All rights reserved  
 Compliance with this standard does not, of itself confer immunity from legal obligations  
A Uganda Standard does not purport to include all necessary provisions of a contract. Users are 
responsible for its correct application  
© UNBS 2021   
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any 
form or by any means, electronic or mechanical, including photocopying and microfilm, without prior written 
permission from UNBS . 
Requests for permission to reproduce this document should be addressed to  
The Executive Director  
Uganda National Bureau of Standards  
P.O. Box 6329  
Kampala  
Uganda  
Tel: +256 41 4 333 2 50/1/2/3  
Fax: +256 41 4 286 123  
E-mail: info@unbs.go.ug  
Web: www.unbs.go.ug  DUS nnnn: 2021  
© UNBS 2021  – All rights reserved  iii 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ .............................  v 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  2 
4 Requirements  ................................ ................................ ................................ ................................ .........  2 
4.1  General  ................................ ................................ ................................ ................................ ...................  2 
4.2  Physical Characteristics  ................................ ................................ ................................ .......................  2 
4.3  Freedom from Impurities  ................................ ................................ ................................ .....................  3 
5 Hygiene  ................................ ................................ ................................ ................................ .............................  3 
6 Microbiological limits  ................................ ................................ ................................ ............................  3 
7 Contaminants  ................................ ................................ ................................ ................................ ...................  4 
7.1 Heavy metals  ................................ ................................ ................................ ................................ .................  4 
7.2 Aflatoxin  ................................ ................................ ................................ ................................ .................  4 
7.3 Pesticide residues  ................................ ................................ ................................ ................................ . 4 
8 Weights and measures  ................................ ................................ ................................ .........................  5 
9 Packaging  ................................ ................................ ................................ ................................ ...............  5 
10 Labelling  ................................ ................................ ................................ ................................ .........................  5 
10.1 General  ................................ ................................ ................................ ................................ ........................  5 
10.2 Labelling of non -retail containers  ................................ ................................ ................................ .............  5 
11 Sampling  ................................ ................................ ................................ ................................ ................  5 
Annex  A  (normative)   DETERMINATION OF YIELD  OF EXTRACT  ................................ ..............................  6 
A.1 APPARATUS  ................................ ................................ ................................ ................................ ..........  6 
A.1.1 Grinding Mill.  ................................ ................................ ................................ ................................ .............  6 
A.1.2 Mash Beaker and Counter Weight.  ................................ ................................ ................................ .........  6 
A.1.3 Mashing Apparatus ................................ ................................ ................................ ................................ ... 6 
A.1.4 Gypsum Plate  ................................ ................................ ................................ ................................ ............  6 
A.1.5 Filter Paper  ................................ ................................ ................................ ................................ ................  6 
A.1.6 Funnels . ................................ ................................ ................................ ................................ .....................  6 
A.1.7 Flasks  ................................ ................................ ................................ ................................ .........................  6 
A.1.8 Pknometers  ................................ ................................ ................................ ................................ ...............  6 
A.1.9 Water -Bath  ................................ ................................ ................................ ................................ .................  6 
A.2. REAGENTS  ................................ ................................ ................................ ................................ ..................  7 
A.2.1 Iodine Solution.  ................................ ................................ ................................ ................................ .........  7 
A.3 DETERMINATION  ................................ ................................ ................................ ................................ .........  7 
A.3.1 Grinding  ................................ ................................ ................................ ................................ .....................  7 
A.3.2 Mashing Procedure ................................ ................................ ................................ ................................ ... 7 
A.3.3 Cooling and filtration  ................................ ................................ ................................ ................................  7 
A.3.4 Specific gravity  ................................ ................................ ................................ ................................ .........  8 
A.4 CALCULATION  ................................ ................................ ................................ ................................ .............  8 
APPENDIX B (normative)  DETERMINATION OF DIFFERENCE IN YIELD OF EXTRACT BETWEEN 
FINE AND COARSE GRINDING  ................................ ................................ ................................ ............  9 
B.1 GRINDING  ................................ ................................ ................................ ................................ .....................  9 
B.1.1 Fine Grinding  ................................ ................................ ................................ ................................ .............  9 
B.1.2 Coarse Grinding  ................................ ................................ ................................ ................................ ........  9 
B.2. YIELD OF EXTRACT  ................................ ................................ ................................ ................................ ... 9 DUS nn nn: 2021   
iv © UNBS 2021  – All rights reserved  
 APPENDIX C  (normative)  DETERMINATION OF SACCHARIFICATION TIME  ................................ ..........  10 
C.1. PROCEDURE  ................................ ................................ ................................ ................................ ............  10 
APPENDIX D  (normative)  DETERMINATION OF MODIFICATION INDEX  ................................ .................  11 
D.1. PRINCIPLE  ................................ ................................ ................................ ................................ ................  11 
D.2. TOTAL NITROGEN  ................................ ................................ ................................ ................................ ... 11 
D.3. TOTAL SOLUBLE NITROGEN  ................................ ................................ ................................ .................  11 
D.3.2 Calculation  ................................ ................................ ................................ ................................ ..............  11 
D.4 MODIFICATION INDEX  ................................ ................................ ................................ ..............................  11 
APPENDIX E DETERMINATION OF COLD WATER EXTRACT  ................................ ................................ .... 12 
E.1 PREPARATION OF SAMPLE  ................................ ................................ ................................ ....................  12 
E.2 PROCEDURE  ................................ ................................ ................................ ................................ ..............  12 
E.3 CALCULATION  ................................ ................................ ................................ ................................ ...........  12 
APPENDIX F  DETERMINATION OF DlASTATIC POWER  ................................ ................................ ............  13 
F.1 REAGENTS  ................................ ................................ ................................ ................................ .................  13 
F.1.1 Acetate Buffer Solution  ................................ ................................ ................................ ..........................  13 
F.1.2 Fehling’s solution  (Soxhlet modification)  ................................ ................................ ............................  13 
F.1.3 Methylene blue solution  ................................ ................................ ................................ .........................  13 
F.1.4 Sodium Chloride  ................................ ................................ ................................ ................................ ..... 13 
F.1.5 Starch Solution  ................................ ................................ ................................ ................................ ....... 13 
F.1.6 Soluble Starch Indicator  ................................ ................................ ................................ ........................  14 
F.2 DETERMINATION  ................................ ................................ ................................ ................................ ....... 14 
F.3 CALCULATION  ................................ ................................ ................................ ................................ ...........  14 
F.3.1 Diastatic Power (as in basis)  ................................ ................................ ................................ .................  14 
F.3.2 Diastatic power (on dry basis)  ................................ ................................ ................................ ..............  14 
Bibliography  ................................ ................................ ................................ ................................ .....................  16 
 DUS nnnn: 2021  
© UNBS 2021  – All rights reserved  v 
 Foreword  
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry of Trade , Industry and 
Cooperatives established under Cap 327 , of th e Laws of Uganda , as amended .  UNBS is mandated to co -
ordinate the elaboration of standards and is  
(a) a member of International Organisation for Standardisation (ISO) and  
(b) a contact point for the WHO/FAO Codex Alimentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT  Agreement  of the World Trade Organisation (WTO).  
The work of preparing Uganda Standards is carried out through Technical Committees. A Technical 
Committee is established to deliberate on standards in a given field or area and consists of key stakeholders 
including government, academia, consumer groups, private sector and other interested parties.  
Draft Uganda Standards adopted by the Technical Committee are widely circulated to stakeholders and the 
general public for comme nts. The committee reviews the comments before recommending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council.  
The committee responsible for this document is Technical Committee UNBS /TC 203, [Cereals, Pu lses and 
related products and processes ] DUS nn nn: 2021   
vi © UNBS 2021  – All rights reserved  
 Introduction  
Malt is an important base ingredient for use in brewing and distilling industries. In addition, maIt is used for 
preparing malt extract, malt vinegar, processed foods meant for infants, children, and m edicinal preparations. 
In order to ensure that the end products are of an acceptable quality, it is essential that the malt used should 
be of appropriate quality. Therefore, in order to make available malt of proper quality to the various groups of 
consumi ng interests, this Uganda Standard is be ing issued. The  use of sorghum grain for brewing malt will 
vastly improve income levels of people in rural areas as well as eliminate any income loss incurred by local 
beverage companies when other raw materials are in short supply.  
Sorghum, finger millet and other cereals have been used to brew traditional opaque beer since time 
immemorial in Africa. The brewing process involves fermentation of malted grains. Currently sorghum is the 
main raw material used to brew op aque beer at commercial level in Uganda. Sorghum ( Sorghum bicolour ) 
and finger millet ( Eulicine  coracana ) grains thrive in areas of low rainfall and are cultivated in drought stricken 
areas in East and Southern Africa  
The quality of opaque beer depends on the malt quality. The quality of malt depends upon several parameters 
such as free amino nitrogen content, diastatic power and germination energy. Malting is a biological process 
that turns grain into malt. Malting of finger millet and sorghum is a common technique in India and Africa and 
malted finger millet is considered superior to malted sorghum and malted maize. Malting results in 
mobilization of hydrolytic enzymes such as amylases and proteases that are essential for the solubilisation of 
starch and p roteins in the grains. This makes the grains easy to ferment. Performance of finger millet in the 
brewing of opaque beer by locals is commendable.  Commercial sales of finger millet will financially boost 
people living in rural areas who produce this crop.  
 DRAFT UGANDA S TANDARD  DUS nnnn : 2021  
 
© UNBS 2021  – All rights reserved  1 
 Sorghum malt  — Specification  
1 Scope   
This standard prescribes the requirements and methods of sampling and test for Sorghum malt.  
2 Normative references   
The following referenced documents referred to in the text in such a way that some or all of their content 
constitutes requirements of this document. For dated references, only the edition cited applies. For undated 
references, the latest edition of the referenced document (including any amendments) applies.  
AOAC 952.13 , Arsenic in food  ― Silver diethyldibocarbamate method  
AOAC 972.23 , Lead in fish ― Atomic absorption spectrophotometric method  
AOAC 973.34 , Cadmium in food ― Atomic absorption spectrophotometric method  
AOAC 983.20 , Mercury (methyl) in fish and shellfish ― Gas chromatograph ic method  
US 1659 , Materials in contact with food — Requirements for packaging materials  
US 28 EAS 39 , Code of practice for hygiene in the food and drink manufacturing industry  
US 738, General standard for contaminants and toxins in food and feed   
US EAS 38, Labelling of pre -packaged foods — General requirements  
US EAS 900 , Cereals and pulses — Sampling  
US EAS 901 , Cereals and pulses — Test methods  
US EAS 757, Whole Sorghum grain  — Specification  
US ISO 15089 , Water quality Guidelines for selective immunoa ssays for the determination of plant treatment 
and pesticide agents  
ISO 16649 -2 
AOAC 967.26  
ISO 6888 -1 
ISO 21527 -2 
  
2 © UNBS 2021  – All rights reserved  
 3 Terms and definitions   
For the purposes of this document, the following terms and definitions apply.  
ISO and IEC maintain terminological databases for use in standardization at the following addresses:  
— ISO Online browsing platform: available at http://www.iso.org/obp  
3.1  
sorghum malt  
product of controlled steeping, germination and drying sorghum grain  
 
3.2 
extract  
percentage of dry sub stance in the  malt which is soluble in water when extracted over a  standard gradient 
regime  
 
3.4 
diastatic Power  
measure of the enzymatic activity of malt ( combined activity of alpha and beta amylases).  
3.5 
Total Nitrogen  
3.6  
Friability 
The measure or tendency of malted grain to crush or crumble  
3.7 
Sacchar ification time  
 
 
4 Requir ements  
4.1  General  
4.1.1  Sorghum m alt shall be prepared from Sorghum  conforming to US EAS 757 
4.1.2  Malt shall be prepared from sorghum grains  with a mi nimum of 85% germination energy  to be 
accepted for malting purposes  
4.2  Specific requirements  
4.2.1  Colour -The colour of malt shall be as agreed between the purchaser and the vendor. Malt shall 
possess a bright appearance and sha ll be free from discolouration and characteristic of parent grain . DUS nnnn: 2021  
© UNB S 2021  – All rights reserved  3 
 4.2.2  Flavour  - Malt shall possess flavour, which is typical and characteristic of clean malt. It shall be free 
from any off -flavours  e.g. mouldy flavours . Malt shall be  sweet to taste, and shall be free from any trace of 
bitterness and sourness.  
4.2.2 Friability  
4.2.3   The size of malted kernels shall be in accordance to US EAS 757 
4.3  Freedom from  Impurities  
4.3.1   Foreign Matter -The proportion of all matter other than malt,  culms rests, etc., shall  not exceed 2 
percent by mass.  
4.3.2   Broken Kernels - The proportion of broken kernels (which are  not whole) shall not exceed 5 percent 
by mass.  
4.3.4   Sorghum  malt shall be free from living insects and mould, and  shall be free from dead insects, insect 
fragments and rodent contamination  visible to the eye .  
4.4  Malt shall also conform to the requirements prescribed in Table I. 
Table 1  — Requirements for Sorghum malt  
S/N Characteristic  Requirements  Method of test  
1 Moisture, percent by mass, Max  8.1  
2 Yield or extraction  
(On dry basis). Percent by mass, Min 
 65  
3 Sacchar ification time  at 700C (Minutes) , Max  60  
4 Diastatic power (on dry basis)  SDU/g , Min  20  
5 Thousand Kernel mass (on dry basis) in g, min  14  
6 Free Amino Nitrogen  (FAN) , Max  50  
 
4.5 The mash and wort when examined as given in A.3.2 and A.3.3 shall  conform to the following 
requirements.  
4.5.1 Mash - It shall be free from mouldy smell (A.3.2 ). 
4.5.2 Wort  - It may be clear,  bright or slightl y opalescent in appearance  where applicable  (A.3.3)  
5 Hygiene  
Sorghum malt  shall be handled in accordance with US 28 EAS 39.  
6 Microbiological limits  
The maximum limits for microbiological contaminants in Sorghum malt shall comply with the requirements i n 
Table 2   
4 © UNBS 2021  – All rights reserved  
 Table 2 ― Microbiological limits for Sorghum malt  
S/No.  Organism  Limit  Test method  
i) Yeasts and moulds, cfu per g max  104 ISO 21527 -2 
ii) Staphylococcus spp., cfu per g max  103 ISO 6888 -1 
iii) Escherichia coli , cfu per g  Absent  ISO 16649 -2 
iv) Salmonella spp. per 25 g  Absent  AOAC 967.26  
 
7 Contaminants  
Sorghum malt  shall comply with maximum levels for contaminants in accordance with US 738.  
7.1 Heavy metals  
Sorghum malt  shall comply with the hea vy metal limits given in Table 2  when tested in accordance wi th the 
test methods specified therein  
Table 3 — Heavy metal limits for Sorghum malt  
S/N Heavy metal  Maximum limit  
mg/kg  Test method  
i.  Arsenic  0.1 AOAC 952.13  
ii.  Lead  0.3 AOAC 972.23  
iii.  Cadmium  0.3 AOAC 973.34  
iv.  Mercury  0.5 AOAC 983.20  
7.2 Mycoto xins 
Sorghum malt shall comply with the maximum limits for mycotoxins given in Table 3 when tested in 
accordance with the test methods specified therein.  
Table 4— Mycotoxins limits for Sorghum malt   
Mycotoxin  Maximum limit  
μg/kg  Test method  
Total aflatox in 10 US EAS 901  
Aflatoxin B1  5 
 
 
7.3 Pesticide residues  
Sorghum malt  shall comply with those maximum pesticides residue limits given in Table 4 when tested in 
accordance with the test methods specified therein.  DUS nnnn: 2021  
© UNB S 2021  – All rights reserved  5 
 Table 5— Pesticide residue limits  in Sorg hum malt  
S/N Pesticide residue  Maximum limit  
mg/kg  Test method  
i Dichloro -diphenyl -
trichloroethane  (DDT)  0.1 
US ISO 15089  ii Polychlorinated 
biphenyls  (PCBs )  0.01 
iii Dioxin  0.01 
 
8 Weights and measures  
Sorghum malt  shall be packaged in accordance  with the weights and meas ures regulations of the country .  
9 Packaging  
9.1 Sorghum malt  shall be packaged in food grade packaging that will safeguard the hygienic, nutritional, 
technological, and organoleptic qualities of the product . Each package shall b e securely sealed.   
9.2 The packaging containers used shall conform to the requirements given in US 1659.  
10 Labelling  
10.1 General  
In addition to the requirements in US EAS 38, each package shall be legibly and indelibly labelled with the 
following:  
a) name of the product as “ Sorghum malt ”;  
b) name, address and physical location of the producer/packer/importer;  
c) lot/batc h/code number/  crop year  and grade ;  
k) declaration on whether the sorghum  was genetically modified, where applicable.  
 
10.2 Label ling of non -retail containers  
10.2.1 Information detailed in 9.1 shall be given either on the container or in accompanying documents, 
except that the name of the product, lot identification and the name and address of the processor or packer as 
well as st orage instructions, shall appear on the container.  
10.2.2 However, lot identification and the name and address of the processor or packer may be replaced by 
an identification mark provided that, such a mark is clearly identifiable with the enclosed  docume nts. 
11 Sampling  
Sampling shall be carried out in accordance with US EAS 900.   
6 © UNBS 2021  – All rights reserved  
 Annex  A  
(normative )  
 
DETERMINATION OF YIELD  OF EXTRACT  
A.1 APPARATUS  
A.1.1 Grinding Mill .  
Miag -Seck type. For fine grinding use cone type, 300 rev/min, and for coarse grindin g roll type, 150 rev/min.  
A.1.2 Mash Beaker and Counter Weight . 
Made of either pure nickel stainless steel or brass and of such dimensions as '0 assure light connection 
between beakers and grinding mill. If counterweights are used for mash beakers, their t are should be checked 
frequently.  
A.1.3 Mashing Apparatus   
The b eakers, stirrers and solder used  should be of the same 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 
force mash upward. Speed of the mash stirrer shall be 80 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 mash level.  
A.1.4  Gypsum Plate  
Thoro ughly mix 100 ml water with 135 g plaster of paris. Pour mixture while still free flowing into suitable fl at 
moulds.  
A.1.5 Filter  Paper    
Whatman No. I or equivalent.  
A.1.6 Funnels .  
Short -stem glass funnels having approximately a diameter  of 20 c m. The stem shall extend 3 to 5 cm into  the 
receiving flask.  
A.1.7  Flasks   
Erlenmeyer’s  of 500 ml capacity . 
A.1.8 P knometers  
A.1.9 Water -Bath   
Automatically  controlled . DUS nnnn: 2021  
© UNB S 2021  – All rights reserved  7 
 A.2. REAGENTS  
A.2.1 Iodi ne Solution . 
A.2.1.1 0 .01 N Sol ution .  
Prepared by dissolving 0. 63 g iodine and  1.25 g of potass ium iodine in water and diluted to 500 ml.  
A.2.1.2 0.02 N Sol ution . 
Prepared by d issolving 1 .27 g of iodine and  2.5 g of potassium iodine in water and diluted in 500 ml. Both 
these  iodine solutions should be kept in dark and prepared fresh once a month.  
A.3 DETERMINATION  
A.3.1  Grinding   
Weigh approximately 55 g of sample at room temper ature  into a tared mash beaker and grind through mill set 
for standardized  fineness of grind. Collect finely ground malt in same mash beaker,  carefully brushing malt 
particle remaining in the mill into the mash  beaker. Mix and without delay place mash beak er with contents on  
balance accurate to within ± 0.06g,  under 750 g load and adjust mass of  the malt to 50  ± 0.05 g by removing 
excess into tared dish for  moisture determination.  
A.3.2 Mashing Procedure  
Mash in ground malt with 200 ml water  at 46QC and mix  well with glass rod to prevent formation of lumps.  
Carefully rinse glass rod and wall of beaker with small quantity of water.  Promptly place mash beakers in 
mashing apparatus containing water  previously heated to 46°C  and set the stirrers in motion. Place  
thermometer  in each mash beaker. Keep temperature at 45°C exactly for  10 minutes from the time beakers 
were placed in the mashing apparatus. Raise mash temperature at the rate of 1°C per minute till it reaches 
70°C.Add 100 ml water which has been previous ly heated to 70 to 71°C and mash for 60 10mutes at 70'C. 
Care should be taken that temperature deviations during mashing procedure do not exceed 0.5°C. Observe 
the odour of the mash; it should be free from mouldy or smoky smell (see 3.5.1).  
A.3.3 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 
each beaker with its stirrer f rom mashing apparatus. Rinse mash particles adhering to the stirrer into beaker 
with water. Dry outside of each beaker taking care to remove the moisture adhering to the rim. Without de lay, 
adjust the mass of content of mash beaker 450 ± 0.05 g by adding w ater. Stir mash thoroughly with glass rod. 
Once  when removing beakers  from balance pan and again immediately before pouring mash onto filter  
(stirrings shall be not less than 5 minutes not more than 15 minutes  apart).  
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 contents of beaker into funnel provided with specified  filter 
paper. Cover funnel with approximately 20 cm diameter watch glass during the entire filtration  and remove 
receiving fla sk containing wort  for later observations and tests. In case of slow running worts, stop  filtration 
after 2 hours. In case of coarse ground malt mash, collect  exactly 200 ±2 ml wort. When filtration is comp lete, 
mix wort in  receiving flask thoroughly by rotary motion. Speed of  filtration is normal  if filtra tion is complete 
within one hour after returning the filtrate to filter bed; s low if filtration  takes longer. Observe degree of clari ty 
and report  as, cle ar, slightly hazy, or hazy (set 3.5.2).  Remove approximately 100 ml wort for determination of 
colour.   
8 © UNBS 2021  – All rights reserved  
 A.3.4 Specific gravity   
Rinse empty pyknometer twice with about  10 ml wort. Fill with wort, place in water -bath maintained at 20°C.  
Weigh filled pyknomete r within 3 hours of completed filtration.  Difference between this mass and that of empty 
pyknometer represents  wort capacity o f pyknometer  at 20°C. Calculate specific gravity of wort  to 5 decimal 
places rounding off to 0.000 05 to  0.000 10, by dividing  mass of wort by mass of water.  
A.4 CALCULA TION 
A.4.1 Determine extract yield of wort by reference to specific gravity  values given in specific gravity table . 
A.4.2 Calculate yield of extract of malt (on dry basis) as given below:  
a) Extract, a s is basis =  P (60 0 + M) / (100 - P) 
where  
P = g extract in 100 g Wo rt (as calculate d from specific gravity table) , and  
M = percent moisture in the malt.  
b) Extract  (on dry basis) = (E x 100)/ (100 -M) 
where  
E = extract as -is basis, and  
M = percent moisture in the malt.  DUS nnnn: 2021  
© UNB S 2021  – All rights reserved  9 
 APPE NDIX B  
(normative)  
DETERMINATION OF DIFFERENCE IN YIELD OF EXTRACT  BETWEEN 
FINE AND COARSE GRINDING  
B.1 GRINDING  
B.1.1 Fine Grinding  
Grind malt sample as described in A.3.I, However , for fine grinding the mill shall have been standardized in 
such a manner  that between 9 to 11  percent by mass of the material is retained  on a 300 micron IS Sieve  
B.1.2 Coarse Grinding  
Grind malt sample as described in A.3.1.In case of coarse grinding, the mill shall have been standardized in 
such a manner that between 74 and 76 percent by mass of the material is retained on a 300 -micron IS Sieve.  
B.2. YIELD OF EXTRACT  
B.2.1  Determine yield of extract of fine and coarse grinding separately and calculate difference in yield.   
10 © UNBS 2021  – All rights reserved  
 APPENDIX C  
(normative )  
DETERMINATION OF SACCHARIFICA TION TIME  
C.1. PROCEDURE  
C.1.1 Procee d up to the stage of mashing (A.3. 2). Ten minutes after the  mash has reached 70°C, transfer 
drop of mash with thin glass rod (of  about 3 mm diameter) on to an absorbent gypsum plate (A.1.4), or into a 
cavity of porcelai n plate, and test with drop of 0. 01 N iodine  solution (A.2.1.1) on g ypsum plate or with a drop 
of 0.02 N iodine  solution (A.2.1.2) on porcelain plate. Make tests 5, 7 and 10 minutes  after 70°C is reached  
and thereafter if necessary at 5 -minute intervals.  Conversion (saccharification) is considered complete when 
test drop and  iodine solution produces only yellow stain on gypsum or porcelain plate.  
C.1.2 Report time of saccharification in minutes.  DUS nnnn: 2021  
© UNB S 2021  – All rights reserved  11 
 APPENDIX D  
(normative)  
DETERMINATION OF MODIFICATION INDEX  
D.1. PRINCIPLE  
D.1.1 Modification index is the ratio of the total soluble nitrogen to  total nitrogen.  
D.2. TOTAL NITROGEN  
D.2.1 Determine total nitrogen or malt by the method prescribed in IS 5194 -1969*  
D.3. TOTAL SOLUBLE NITROGEN  
D.3.1 Determine total solu ble nitrogen on the wort obtained from the  standard hot water extract (A -3.3). Take 
25 ml or the wort in 5QO -m1 Kjeldahl flask, and determine nitrogen by the method prescribed in  IS: 5194 -
1969*, Carry out a blank determination in tbe same manner  using the same quantities or all the reagents but 
without the sample.  
D.3.2 Calculation  
Total soluble Nit rogen = (V X 5.6)/W 
where  
V = volume in ml or standard sulphuric acid used in titration,  
and 
W = mass in g or dry matter in the sample.  
D.4 MOD IFICATI ON INDEX  
4.1 Modification index = (A/B)  X 100 
where  
A = total soluble nitrogen percent by mass, and  
B = total nitrogen or malt percent by mass,   
12 © UNBS 2021  – All rights reserved  
 APPENDIX E  
DETERMINATION OF COLD WATER EXTRACT  
E.1 PREPARATION OF SAMPLE  
E.1.1 Prepare sample of  barley mal t by grinding as described in A. 3.1. 
E.1.2  Test Portio n - Weigh to the nearest 0'001 g about 25 g or the  prepared sample.  
E.2 PROCEDUR E 
E.2.1 Use distilled water or water of at least equal purity. The temperature  of water to be use d during 
extraction should be O0C. Transfe r the  test portion quantitatively with water to the volumetric flask and fill to  
the mark with cold water. Stopper the flask and shake  at approximately  30 minutes intervals for 3 hours and 
allow to stand ove rnight without  shaking. Filter the extract throug h a dry filter paper, evaporate a 50 ml  aliquot 
portion to dryness in the dish in the steam -bath and heat in the  oven at 103 ±2°C to  constant mass, that is, 
until two consecutive  weighing s separated by a period of one hour in the oven do not differ by  more  than 
0.002 g. Record the final mass.  
E.3 CALCULATION  
E.3.1 Cold water extract, percent by  mass (on dry basis) = M, X 
100 100 100  
50 X Mo X lOO -H 
where  
M1 = mass in g of the residue obtained,  
M0 = mass in g of the test portion, and  
H = moisture content, pe rcent by mass of the test sample.  DUS nnnn: 2021  
© UNB S 2021  – All rights reserved  13 
 APPENDIX F  
 DETERMINATION OF DlASTATIC POWER  
F.1 REAGENTS  
F.1.1 Acetate Buffer Solution  
Dissolve 68 g sodium acetate in 500 ml  of 1N acetic acid and dilute to one litre with water,  
F.1.2 Fehling’s solution (Soxhlet modific ation)   
Mix by Pouring  Immediately' before use, equal volumes of solution A prepared as described under '-1.2.1 and 
solution B prepared as described under F.1.2.2. Check  against 0. 1 percent invert sugar solution by the 
method of titration  described under F.2.2 so that 5 ml of Fehling’s 25  solution corresponds to  0.025 33 g of 
invert sugar.  
F.1.2.1 Solution A   
 Dissolve 34 '639 g of copper sulphate (CuSO 4 5H2O) in water, and 0. 5 ml of concentrated sulphuric acid of sp 
gr 1-84 conforming to analytical reagent grade of IS 266-1961· and dilute to  500 ml in a graduated flask and 
allow the solution to stand for two days.  Filter this solution through prepared asbestos.  
F.1.2.2 Solution B  
Dissolve 173 g of Rochelle salt [potassium -sodium  tartrate (KNaC 4H4O8. 4H 2O)] and 50 g of sodium 
hydroxide, analytical  reagent (conforming to IS:376 -1969t) in water, dilute to 500 ml in a  graduated flask and 
allow the solution to stand for two days. Filter this  solution through prepared asbestos.  
F.1.3 Methylene blue solution  
 Disso lve 1. 0 g of methylene blue  in water and dilute to 100 ml . 
F.1.4 Sodium Chloride    
0.5 percent.  
F.1.5 Starch Solutio n 
The final concentration shall represent 2 g  soluble starch (weighed on dry basis)  In 100 ml solution. The 
soluble  starch to be used should  be specially suitable for determining diastatic  power, shall possess solubility 
at least I: 50 in hot water, shall contain no  dextrins, shall contain less than 0. 75 percent reducing substances  
calculated as m altose, has moisture content of 10 to 12 percen t and  freshly made 2 perc ent solution shall 
have pH of 4. 5 to 5 .5 without  adjustment with buffer  
F.1.5.1 Macerate starch with just enough cold freshly distilled water to  form smooth, thin paste. Pour, with 
constant stirring, into boiling  fresh distilled wa ter representing not less than approximately 75 percent  of final 
volume of starch solution, at such a rate that boiling does not  cease. Continue boiling for 2 minutes after thin 
paste is completely  added. Quickly add to beaker additional 10 percent of fina l volume  of cold, freshly distilled 
water and transfer mixture quantitatively to glass  stoppered volumetric flask. Mix by in verting flask, wash down 
neck  off task , and cool to 20°C before adding buffer solution. Add 2 ml buffer  solution for each 100 ml of final 
volume of starch solution and dilute  to the mark. Mix again by inverting flask and keep tightly stoppered  at 
20°C until used.   
14 © UNBS 2021  – All rights reserved  
 F.1.6 Soluble Starch Indicator   
One percent soluble starch in  30 percent sodium chloride solution. Prepare soluble starch su spension  and 
pour slowly in to boil ing water . Add sodium chloride and dilute to  volume. (Solutio n should be transparent and 
colourless.)  
F.2 DETERMINATION  
F.2.1 Grind separately not less than 25.5 g malt as in A. 3.1. Collect  finely ground malt in mash beake r, 
carefully brushing in malt particles  remaining in m ill. Without delay, adjust mass of contents to 25 ±0.5 g. 
Transfer quantitatively to container (about I litre capacity) in which  infusion is to be made. Add 500 ml of 0'5 
percent sodium chloride  solution  at 20°C and close the cont ainer. Let infusion stand for 2. 5 hours  at 20 ± 
0.2°C and agitate by rotating at 20 -minute intervals. Take care  that in agitation of malt suspension as small 
quantity of grit as possible is  left adhering to inner surface of flask  above level of the water. (Do not  invert flask 
to mix; gentle whirling of contents without splashing on sides  of container is sufficient.) Filter infusion by 
transferring entire charge to  a fluted filter. Return first 50 ml filtrate to filter, Collect fil trate for  3 hours  after 
water and ground malt were first mixed. Prevent evaporation  during filtration as far as possible by placing 
water on watch -glass  over funnel and some suitable cover around stem of funnel, resting on  neck of receiver.  
Immediately dil ute 20 ml of this infusion to 100 ml with 0'5 percent  sodium chloride solution at 20DC. Transfer 
10 ml diluted infusion to  250 ml volumetric flask and bring to 20°C. Add 200 ml buffered starch  solution from 
fast flowing pipette all at 20°C. Mix solution by  rotating  flask during addition. Keep starch infusion mixture at 
20 ± 0.1 oC exactly for 30 minutes timed on stop -watch from time addition of starch  was begun. Add 20 ml of 
0'5 N sodium hydroxide rapidly and mix well  by whirling the flask. Dilute to the ma rk at 20°C and mix 
thoroughly.  
F.2.2 Boil 10 ml of the Fehling’s  solution and 10 ml water in a 200 ml Erlenmeyer flask, add from burette about 
two-thirds of quantity of  digested starch solution (F.2.1) and boil for 15 to 20 seconds rotating  constantly. 
Remo ve from heat. If still decidedly blue, add more  solution, boil for about 10 minutes and again observe 
colour. When blue  is almost discharged, and after solution boils gently for about 2 minutes,  add 3 drops of 
methylene blue solution. Continue boiling and add more  solution until 0'1 ml, or ,even one drop, discharges 
blue upon boiling.  Repeat titration adding at once almost whole quantity of digested  starch required, and 
proceed to end -point as directed. Designate  quantity of digested starch solution require d to reach end point in 
this second titration as 'A', Interrupt boiling as little as possible after  indicator is added, so that flask remains 
.filled with steam, preventing  much excess of air.  Prepare blank by processing exactly as in F.2.1. Except  that, 
add the 0. 5 N sodium hydroxide to malt infusion before adding the starch  solution. To 10 ml of the Fehling,  
solution and 10 ml of water add  a volume of this blank solution equal to final volume of digested starch  
solution. Boil and again determine end -point  as in the determination.  Designate quantity of digested starch 
solution used as 'B'.  
F.3 CALCULATION  
F.3.1 Dias tatic Power ( as in basis ) 
= (5 OOOIA) x (BIA)  
where  
A = volume in ml of digested starch solution, and  
B = volume in ml of diges ted starch soluti on required to reduce 10 ml of Fehling's solution.  
F.3.2 Diastatic power (on dry basis)   
= (DP x 100)/( 100 - M} DUS nnnn: 2021  
© UNB S 2021  – All rights reserved  15 
 where  
DP = diastatic power, as -is b... is; and  
M = percent by mass of moisture in the sample.   
16 © UNBS 2021  – All rights reserved  
 Bibliography  
[1] IS 6895 -1973, Indian Standard s pecification for barley malt  
[2] US 334 :2020 , Barley grains — Specification  
[3] India Online ISSN: 2319 -7064, Volume 2 Issue 9, September 2013, International Journal of Science and 
Research (IJSR)  
 US nnnn -n: 2021  
© UNBS 2021  – All rights reserved  17 
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The use of the UNBS Certification Mark is governed by the Standards Act, and the Regulations made 
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certification mark scheme of the Uganda National Bureau of Standards. UNBS marked products are 
continually checked by UNBS for conformity  to that standard.  
Further particulars of the terms and conditions of licensing may be obtained from the Director, Uganda 
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